<project title="FastHTML" summary='FastHTML is a python library which brings together Starlette, Uvicorn, HTMX, and fastcore&#39;s `FT` "FastTags" into a library for creating server-rendered hypermedia applications. The `FastHTML` class itself inherits from `Starlette`, and adds decorator-based routing with many additions, Beforeware, automatic `FT` to HTML rendering, and much more.'>Things to remember when writing FastHTML apps:

- Although parts of its API are inspired by FastAPI, it is *not* compatible with FastAPI syntax and is not targeted at creating API services
- FastHTML includes support for Pico CSS and the fastlite sqlite library, although using both are optional; sqlalchemy can be used directly or via the fastsql library, and any CSS framework can be used. Support for the Surreal and css-scope-inline libraries are also included, but both are optional
- FastHTML is compatible with JS-native web components and any vanilla JS library, but not with React, Vue, or Svelte
- Use `serve()` for running uvicorn (`if __name__ == "__main__"` is not needed since it's automatic)
- When a title is needed with a response, use `Titled`; note that that already wraps children in `Container`, and already includes both the meta title as well as the H1 element.<docs><doc title="FastHTML concise guide" desc="A brief overview of idiomatic FastHTML apps"># Concise reference



## About FastHTML

``` python
from fasthtml.common import *
```

FastHTML is a python library which brings together Starlette, Uvicorn,
HTMX, and fastcore’s `FT` “FastTags” into a library for creating
server-rendered hypermedia applications. The
[`FastHTML`](https://www.fastht.ml/docs/api/core.html#fasthtml) class
itself inherits from `Starlette`, and adds decorator-based routing with
many additions, Beforeware, automatic `FT` to HTML rendering, and much
more.

Things to remember when writing FastHTML apps:

- *Not* compatible with FastAPI syntax; FastHTML is for HTML-first apps,
  not API services (although it can implement APIs too)
- FastHTML includes support for Pico CSS and the fastlite sqlite
  library, although using both are optional; sqlalchemy can be used
  directly or via the fastsql library, and any CSS framework can be
  used. MonsterUI is a richer FastHTML-first component framework with
  similar capabilities to shadcn
- FastHTML is compatible with JS-native web components and any vanilla
  JS library, but not with React, Vue, or Svelte
- Use [`serve()`](https://www.fastht.ml/docs/api/core.html#serve) for
  running uvicorn (`if __name__ == "__main__"` is not needed since it’s
  automatic)
- When a title is needed with a response, use
  [`Titled`](https://www.fastht.ml/docs/api/xtend.html#titled); note
  that that already wraps children in
  [`Container`](https://www.fastht.ml/docs/api/pico.html#container), and
  already includes both the meta title as well as the H1 element.

## Minimal App

The code examples here use fast.ai style: prefer ternary op, 1-line
docstring, minimize vertical space, etc. (Normally fast.ai style uses
few if any comments, but they’re added here as documentation.)

A minimal FastHTML app looks something like this:

``` python
# Meta-package with all key symbols from FastHTML and Starlette. Import it like this at the start of every FastHTML app.
from fasthtml.common import *
# The FastHTML app object and shortcut to `app.route`
app,rt = fast_app()

# Enums constrain the values accepted for a route parameter
name = str_enum('names', 'Alice', 'Bev', 'Charlie')

# Passing a path to `rt` is optional. If not passed (recommended), the function name is the route ('/foo')
# Both GET and POST HTTP methods are handled by default
# Type-annotated params are passed as query params (recommended) unless a path param is defined (which it isn't here)
@rt
def foo(nm: name):
    # `Title` and `P` here are FastTags: direct m-expression mappings of HTML tags to Python functions with positional and named parameters. All standard HTML tags are included in the common wildcard import.
    # When a tuple is returned, this returns concatenated HTML partials. HTMX by default will use a title HTML partial to set the current page name. HEAD tags (e.g. Meta, Link, etc) in the returned tuple are automatically placed in HEAD; everything else is placed in BODY.
    # FastHTML will automatically return a complete HTML document with appropriate headers if a normal HTTP request is received. For an HTMX request, however, just the partials are returned.
    return Title("FastHTML"), H1("My web app"), P(f"Hello, {name}!")
# By default `serve` runs uvicorn on port 5001. Never write `if __name__ == "__main__"` since `serve` checks it internally.
serve()
```

To run this web app:

``` bash
python main.py  # access via localhost:5001
```

## FastTags (aka FT Components or FTs)

FTs are m-expressions plus simple sugar. Positional params map to
children. Named parameters map to attributes. Aliases must be used for
Python reserved words.

``` python
tags = Title("FastHTML"), H1("My web app"), P(f"Let's do this!", cls="myclass")
tags
```

    (title(('FastHTML',),{}),
     h1(('My web app',),{}),
     p(("Let's do this!",),{'class': 'myclass'}))

This example shows key aspects of how FTs handle attributes:

``` python
Label(
    "Choose an option", 
    Select(
        Option("one", value="1", selected=True),  # True renders just the attribute name
        Option("two", value=2, selected=False),   # Non-string values are converted to strings. False omits the attribute entirely
        cls="selector", id="counter",             # 'cls' becomes 'class'
        **{'@click':"alert('Clicked');"},         # Dict unpacking for attributes with special chars
    ),
    _for="counter",                               # '_for' becomes 'for' (can also use 'fr')
)
```

Classes with `__ft__` defined are rendered using that method.

``` python
class FtTest:
    def __ft__(self): return P('test')
    
to_xml(FtTest())
```

    '<p>test</p>\n'

You can create new FTs by importing the new component from
`fasthtml.components`. If the FT doesn’t exist within that module,
FastHTML will create it.

``` python
from fasthtml.components import Some_never_before_used_tag

Some_never_before_used_tag()
```

``` html
<some-never-before-used-tag></some-never-before-used-tag>
```

FTs can be combined by defining them as a function.

``` python
def Hero(title, statement): return Div(H1(title),P(statement), cls="hero")
to_xml(Hero("Hello World", "This is a hero statement"))
```

    '<div class="hero">\n  <h1>Hello World</h1>\n  <p>This is a hero statement</p>\n</div>\n'

When handling a response, FastHTML will automatically render FTs using
the `to_xml` function.

``` python
to_xml(tags)
```

    '<title>FastHTML</title>\n<h1>My web app</h1>\n<p class="myclass">Let&#x27;s do this!</p>\n'

## JS

The [`Script`](https://www.fastht.ml/docs/api/xtend.html#script)
function allows you to include JavaScript. You can use Python to
generate parts of your JS or JSON like this:

``` python
# In future snippets this import will not be shown, but is required
from fasthtml.common import * 
app,rt = fast_app(hdrs=[Script(src="https://cdn.plot.ly/plotly-2.32.0.min.js")])
# `index` is a special function name which maps to the `/` route. 
@rt
def index():
    data = {'somedata':'fill me in…'}
    # `Titled` returns a title tag and an h1 tag with the 1st param, with remaining params as children in a `Main` parent.
    return Titled("Chart Demo", Div(id="myDiv"), Script(f"var data = {data}; Plotly.newPlot('myDiv', data);"))
# In future snippets `serve() will not be shown, but is required
serve()
```

Prefer Python whenever possible over JS. Never use React or shadcn.

## fast_app hdrs

``` python
# In future snippets we'll skip showing the `fast_app` call if it has no params
app, rt = fast_app(
    pico=False, # The Pico CSS framework is included by default, so pass `False` to disable it if needed. No other CSS frameworks are included.
    # These are added to the `head` part of the page for non-HTMX requests.
    hdrs=(
        Link(rel='stylesheet', href='assets/normalize.min.css', type='text/css'),
        Link(rel='stylesheet', href='assets/sakura.css', type='text/css'),
        Style("p {color: red;}"),
        # `MarkdownJS` and `HighlightJS` are available via concise functions
        MarkdownJS(), HighlightJS(langs=['python', 'javascript', 'html', 'css']),
        # by default, all standard static extensions are served statically from the web app dir,
        #   which can be modified using e.g `static_path='public'`
        )
)

@rt
def index(req): return Titled("Markdown rendering example",
                              # This will be client-side rendered to HTML with highlight-js
                              Div("*hi* there",cls="marked"),
                              # This will be syntax highlighted
                              Pre(Code("def foo(): pass")))
```

## Responses

Routes can return various types:

1.  FastTags or tuples of FastTags (automatically rendered to HTML)
2.  Standard Starlette responses (used directly)
3.  JSON-serializable types (returned as JSON in a plain text response)

``` python
@rt("/{fname:path}.{ext:static}")
async def serve_static_file(fname:str, ext:str): return FileResponse(f'public/{fname}.{ext}')

app, rt = fast_app(hdrs=(MarkdownJS(), HighlightJS(langs=['python', 'javascript'])))
@rt
def index(): 
    return Titled("Example",
                  Div("*markdown* here", cls="marked"),
                  Pre(Code("def foo(): pass")))
```

Route functions can be used in attributes like `href` or `action` and
will be converted to paths. Use `.to()` to generate paths with query
parameters.

``` python
@rt
def profile(email:str): return fill_form(profile_form, profiles[email])

profile_form = Form(action=profile)(
    Label("Email", Input(name="email")),
    Button("Save", type="submit")
)

user_profile_path = profile.to(email="user@example.com")  # '/profile?email=user%40example.com'
```

``` python
from dataclasses import dataclass

app,rt = fast_app()
```

When a route handler function is used as a fasttag attribute (such as
`href`, `hx_get`, or `action`) it is converted to that route’s path.
[`fill_form`](https://www.fastht.ml/docs/api/components.html#fill_form)
is used to copy an object’s matching attrs into matching-name form
fields.

``` python
@dataclass
class Profile: email:str; phone:str; age:int
email = 'john@example.com'
profiles = {email: Profile(email=email, phone='123456789', age=5)}
@rt
def profile(email:str): return fill_form(profile_form, profiles[email])

profile_form = Form(method="post", action=profile)(
        Fieldset(
            Label('Email', Input(name="email")),
            Label("Phone", Input(name="phone")),
            Label("Age", Input(name="age"))),
        Button("Save", type="submit"))
```

## Testing

We can use `TestClient` for testing.

``` python
from starlette.testclient import TestClient
```

``` python
path = "/profile?email=john@example.com"
client = TestClient(app)
htmx_req = {'HX-Request':'1'}
print(client.get(path, headers=htmx_req).text)
```

    <form enctype="multipart/form-data" method="post" action="/profile"><fieldset><label>Email       <input name="email" value="john@example.com">
    </label><label>Phone       <input name="phone" value="123456789">
    </label><label>Age       <input name="age" value="5">
    </label></fieldset><button type="submit">Save</button></form>

## Form Handling and Data Binding

When a dataclass, namedtuple, etc. is used as a type annotation, the
form body will be unpacked into matching attribute names automatically.

``` python
@rt
def edit_profile(profile: Profile):
    profiles[email]=profile
    return RedirectResponse(url=path)

new_data = dict(email='john@example.com', phone='7654321', age=25)
print(client.post("/edit_profile", data=new_data, headers=htmx_req).text)
```

    <form enctype="multipart/form-data" method="post" action="/profile"><fieldset><label>Email       <input name="email" value="john@example.com">
    </label><label>Phone       <input name="phone" value="7654321">
    </label><label>Age       <input name="age" value="25">
    </label></fieldset><button type="submit">Save</button></form>

## fasttag Rendering Rules

The general rules for rendering children inside tuples or fasttag
children are: - `__ft__` method will be called (for default components
like `P`, `H2`, etc. or if you define your own components) - If you pass
a string, it will be escaped - On other python objects, `str()` will be
called

If you want to include plain HTML tags directly into e.g. a `Div()` they
will get escaped by default (as a security measure to avoid code
injections). This can be avoided by using `Safe(...)`, e.g to show a
data frame use `Div(NotStr(df.to_html()))`.

## Exceptions

FastHTML allows customization of exception handlers.

``` python
def not_found(req, exc): return Titled("404: I don't exist!")
exception_handlers = {404: not_found}
app, rt = fast_app(exception_handlers=exception_handlers)
```

## Cookies

We can set cookies using the
[`cookie()`](https://www.fastht.ml/docs/api/core.html#cookie) function.

``` python
@rt
def setcook(): return P(f'Set'), cookie('mycookie', 'foobar')
print(client.get('/setcook', headers=htmx_req).text)
```

     <p>Set</p>

``` python
@rt
def getcook(mycookie:str): return f'Got {mycookie}'
# If handlers return text instead of FTs, then a plaintext response is automatically created
print(client.get('/getcook').text)
```

    Got foobar

FastHTML provide access to Starlette’s request object automatically
using special `request` parameter name (or any prefix of that name).

``` python
@rt
def headers(req): return req.headers['host']
```

## Request and Session Objects

FastHTML provides access to Starlette’s session middleware automatically
using the special `session` parameter name (or any prefix of that name).

``` python
@rt
def profile(req, sess, user_id: int=None):
    ip = req.client.host
    sess['last_visit'] = datetime.now().isoformat()
    visits = sess.setdefault('visit_count', 0) + 1
    sess['visit_count'] = visits
    user = get_user(user_id or sess.get('user_id'))
    return Titled(f"Profile: {user.name}", 
                  P(f"Visits: {visits}"), 
                  P(f"IP: {ip}"),
                  Button("Logout", hx_post=logout))
```

Handler functions can return the
[`HtmxResponseHeaders`](https://www.fastht.ml/docs/api/core.html#htmxresponseheaders)
object to set HTMX-specific response headers.

``` python
@rt
def htmlredirect(app): return HtmxResponseHeaders(location="http://example.org")
```

## APIRouter

[`APIRouter`](https://www.fastht.ml/docs/api/core.html#apirouter) lets
you organize routes across multiple files in a FastHTML app.

``` python
# products.py
ar = APIRouter()

@ar
def details(pid: int): return f"Here are the product details for ID: {pid}"

@ar
def all_products(req):
    return Div(
        Div(
            Button("Details",hx_get=details.to(pid=42),hx_target="#products_list",hx_swap="outerHTML",),
        ), id="products_list")
```

``` python
# main.py
from products import ar,all_products

app, rt = fast_app()
ar.to_app(app)

@rt
def index():
    return Div(
        "Products",
        hx_get=all_products, hx_swap="outerHTML")
```

## Toasts

Toasts can be of four types:

- info
- success
- warning
- error

Toasts require the use of the `setup_toasts()` function, plus every
handler needs:

- The session argument
- Must return FT components

``` python
setup_toasts(app)

@rt
def toasting(session):
    add_toast(session, f"cooked", "info")
    add_toast(session, f"ready", "success")
    return Titled("toaster")
```

`setup_toasts(duration)` allows you to specify how long a toast will be
visible before disappearing.10 seconds.

Authentication and authorization are handled with Beforeware, which
functions that run before the route handler is called.

## Auth

``` python
def user_auth_before(req, sess):
    # `auth` key in the request scope is automatically provided to any handler which requests it and can not be injected
    auth = req.scope['auth'] = sess.get('auth', None)
    if not auth: return RedirectResponse('/login', status_code=303)

beforeware = Beforeware(
    user_auth_before,
    skip=[r'/favicon\.ico', r'/static/.*', r'.*\.css', r'.*\.js', '/login', '/']
)

app, rt = fast_app(before=beforeware)
```

## Server-Side Events (SSE)

FastHTML supports the HTMX SSE extension.

``` python
import random
hdrs=(Script(src="https://unpkg.com/htmx-ext-sse@2.2.3/sse.js"),)
app,rt = fast_app(hdrs=hdrs)

@rt
def index(): return Div(hx_ext="sse", sse_connect="/numstream", hx_swap="beforeend show:bottom", sse_swap="message")

# `signal_shutdown()` gets an event that is set on shutdown
shutdown_event = signal_shutdown()

async def number_generator():
    while not shutdown_event.is_set():
        data = Article(random.randint(1, 100))
        yield sse_message(data)

@rt
async def numstream(): return EventStream(number_generator())
```

## Websockets

FastHTML provides useful tools for HTMX’s websockets extension.

``` python
# These HTMX extensions are available through `exts`:
#   head-support preload class-tools loading-states multi-swap path-deps remove-me ws chunked-transfer
app, rt = fast_app(exts='ws')

def mk_inp(): return Input(id='msg', autofocus=True)

@rt
async def index(request):
    # `ws_send` tells HTMX to send a message to the nearest websocket based on the trigger for the form element
    cts = Div(
        Div(id='notifications'),
        Form(mk_inp(), id='form', ws_send=True),
        hx_ext='ws', ws_connect='/ws')
    return Titled('Websocket Test', cts)

async def on_connect(send): await send(Div('Hello, you have connected', id="notifications"))
async def on_disconnect(ws): print('Disconnected!')

@app.ws('/ws', conn=on_connect, disconn=on_disconnect)
async def ws(msg:str, send):
    # websocket hander returns/sends are treated as OOB swaps
    await send(Div('Hello ' + msg, id="notifications"))
    return Div('Goodbye ' + msg, id="notifications"), mk_inp()
```

Sample chatbot that uses FastHTML’s `setup_ws` function:

``` py
app = FastHTML(exts='ws')
rt = app.route
msgs = []

@rt('/')
def home():
    return Div(hx_ext='ws', ws_connect='/ws')(
        Div(Ul(*[Li(m) for m in msgs], id='msg-list')),
        Form(Input(id='msg'), id='form', ws_send=True)
    )

async def ws(msg:str):
    msgs.append(msg)
    await send(Ul(*[Li(m) for m in msgs], id='msg-list'))

send = setup_ws(app, ws)
```

### Single File Uploads

[`Form`](https://www.fastht.ml/docs/api/xtend.html#form) defaults to
“multipart/form-data”. A Starlette UploadFile is passed to the handler.

``` python
upload_dir = Path("filez")

@rt
def index():
    return (
        Form(hx_post=upload, hx_target="#result")(
            Input(type="file", name="file"),
            Button("Upload", type="submit")),
        Div(id="result")
    )

# Use `async` handlers where IO is used to avoid blocking other clients
@rt
async def upload(file: UploadFile):
    filebuffer = await file.read()
    (upload_dir / file.filename).write_bytes(filebuffer)
    return P('Size: ', file.size)
```

For multi-file, use `Input(..., multiple=True)`, and a type annotation
of `list[UploadFile]` in the handler.

## Fastlite

Fastlite and the MiniDataAPI specification it’s built on are a
CRUD-oriented API for working with SQLite. APSW and apswutils is used to
connect to SQLite, optimized for speed and clean error handling.

``` python
from fastlite import *
```

``` python
db = database(':memory:') # or database('data/app.db')
```

Tables are normally constructed with classes, field types are specified
as type hints.

``` python
class Book: isbn: str; title: str; pages: int; userid: int
# The transform arg instructs fastlite to change the db schema when fields change.
# Create only creates a table if the table doesn't exist.
books = db.create(Book, pk='isbn', transform=True)
                
class User: id: int; name: str; active: bool = True
# If no pk is provided, id is used as the primary key.
users = db.create(User, transform=True)
users
```

    <Table user (id, name, active)>

### Fastlite CRUD operations

Every operation in fastlite returns a full superset of dataclass
functionality.

``` python
user = users.insert(name='Alex',active=False)
user
```

    User(id=1, name='Alex', active=0)

``` python
# List all records
users()
```

    [User(id=1, name='Alex', active=0)]

``` python
# Limit, offset, and order results:
users(order_by='name', limit=2, offset=1)

# Filter on the results
users(where="name='Alex'")

# Placeholder for avoiding injection attacks
users("name=?", ('Alex',))

# A single record by pk
users[user.id]
```

    User(id=1, name='Alex', active=0)

Test if a record exists by using `in` keyword on primary key:

``` python
1 in users
```

    True

Updates (which take a dict or a typed object) return the updated record.

``` python
user.name='Lauren'
user.active=True
users.update(user)
```

    User(id=1, name='Lauren', active=1)

`.xtra()` to automatically constrain queries, updates, and inserts from
there on:

``` python
users.xtra(active=True)
users()
```

    [User(id=1, name='Lauren', active=1)]

Deleting by pk:

``` python
users.delete(user.id)
```

    <Table user (id, name, active)>

NotFoundError is raised by pk `[]`, updates, and deletes.

``` python
try: users['Amy']
except NotFoundError: print('User not found')
```

    User not found

## MonsterUI

MonsterUI is a shadcn-like component library for FastHTML. It adds the
Tailwind-based libraries FrankenUI and DaisyUI to FastHTML, as well as
Python’s mistletoe for Markdown, HighlightJS for code highlighting, and
Katex for latex support, following semantic HTML patterns when possible.
It is recommended for when you wish to go beyond the basics provided by
FastHTML’s built-in pico support.

A minimal app:

``` python
from fasthtml.common import *
from monsterui.all import *

app, rt = fast_app(hdrs=Theme.blue.headers(highlightjs=True)) # Use MonsterUI blue theme and highlight code in markdown

@rt
def index():
    socials = (('github','https://github.com/AnswerDotAI/MonsterUI'),)
    return Titled("App",
        Card(
            P("App", cls=TextPresets.muted_sm),
            # LabelInput, DivLAigned, and UkIconLink are non-semantic MonsterUI FT Components,
            LabelInput('Email', type='email', required=True),
            footer=DivLAligned(*[UkIconLink(icon,href=url) for icon,url in socials])))
```

MonsterUI recommendations:

- Use defaults as much as possible, for example
  [`Container`](https://www.fastht.ml/docs/api/pico.html#container) in
  monsterui already has defaults for margins
- Use `*T` for button styling consistency, for example
  `cls=ButtonT.destructive` for a red delete button or
  `cls=ButtonT.primary` for a CTA button
- Use `Label*` functions for forms as much as possible
  (e.g. `LabelInput`, `LabelRange`) which creates and links both the
  `FormLabel` and user input appropriately to avoid boiler plate.

Flex Layout Elements (such as `DivLAligned` and `DivFullySpaced`) can be
used to create layouts concisely

``` python
def TeamCard(name, role, location="Remote"):
    icons = ("mail", "linkedin", "github")
    return Card(
        DivLAligned(
            DiceBearAvatar(name, h=24, w=24),
            Div(H3(name), P(role))),
        footer=DivFullySpaced(
            DivHStacked(UkIcon("map-pin", height=16), P(location)),
            DivHStacked(*(UkIconLink(icon, height=16) for icon in icons))))
```

Forms are styled and spaced for you without significant additional
classes.

``` python
def MonsterForm():
    relationship = ["Parent",'Sibling', "Friend", "Spouse", "Significant Other", "Relative", "Child", "Other"]
    return Div(
        DivCentered(
            H3("Emergency Contact Form"),
            P("Please fill out the form completely", cls=TextPresets.muted_sm)),
        Form(
            Grid(LabelInput("Name",id='name'),LabelInput("Email",     id='email')),
            H3("Relationship to patient"),
            Grid(*[LabelCheckboxX(o) for o in relationship], cols=4, cls='space-y-3'),
            DivCentered(Button("Submit Form", cls=ButtonT.primary))),
        cls='space-y-4')
```

Text can be styled with markdown automatically with MonsterUI

```` python
render_md("""
# My Document

> Important note here

+ List item with **bold**
+ Another with `code`

```python
def hello():
    print("world")
```
""")
````

    '<div><h1 class="uk-h1 text-4xl font-bold mt-12 mb-6">My Document</h1>\n<blockquote class="uk-blockquote pl-4 border-l-4 border-primary italic mb-6">\n<p class="text-lg leading-relaxed mb-6">Important note here</p>\n</blockquote>\n<ul class="uk-list uk-list-bullet space-y-2 mb-6 ml-6 text-lg">\n<li class="leading-relaxed">List item with <strong>bold</strong></li>\n<li class="leading-relaxed">Another with <code class="uk-codespan px-1">code</code></li>\n</ul>\n<pre class="bg-base-200 rounded-lg p-4 mb-6"><code class="language-python uk-codespan px-1 uk-codespan px-1 block overflow-x-auto">def hello():\n    print("world")\n</code></pre>\n</div>'

Or using semantic HTML:

``` python
def SemanticText():
    return Card(
        H1("MonsterUI's Semantic Text"),
        P(
            Strong("MonsterUI"), " brings the power of semantic HTML to life with ",
            Em("beautiful styling"), " and ", Mark("zero configuration"), "."),
        Blockquote(
            P("Write semantic HTML in pure Python, get modern styling for free."),
            Cite("MonsterUI Team")),
        footer=Small("Released February 2025"),)
```</doc><doc title="HTMX reference" desc="Brief description of all HTMX attributes, CSS classes, headers, events, extensions, js lib methods, and config options">+++
title = "Reference"
+++

## Contents

* [htmx Core Attributes](#attributes)
* [htmx Additional Attributes](#attributes-additional)
* [htmx CSS Classes](#classes)
* [htmx Request Headers](#request_headers)
* [htmx Response Headers](#response_headers)
* [htmx Events](#events)
* [htmx Extensions](/extensions)
* [JavaScript API](#api)
* [Configuration Options](#config)

## Core Attribute Reference {#attributes}

The most common attributes when using htmx.

<div class="info-table">

| Attribute                                        | Description                                                                                                        |
|--------------------------------------------------|--------------------------------------------------------------------------------------------------------------------|
| [`hx-get`](@/attributes/hx-get.md)               | issues a `GET` to the specified URL                                                                                |
| [`hx-post`](@/attributes/hx-post.md)             | issues a `POST` to the specified URL                                                                               |
| [`hx-on*`](@/attributes/hx-on.md)                | handle events with inline scripts on elements                                                                      |
| [`hx-push-url`](@/attributes/hx-push-url.md)     | push a URL into the browser location bar to create history                                                         |
| [`hx-select`](@/attributes/hx-select.md)         | select content to swap in from a response                                                                          |
| [`hx-select-oob`](@/attributes/hx-select-oob.md) | select content to swap in from a response, somewhere other than the target (out of band)                           |
| [`hx-swap`](@/attributes/hx-swap.md)             | controls how content will swap in (`outerHTML`, `beforeend`, `afterend`, ...)                                      |
| [`hx-swap-oob`](@/attributes/hx-swap-oob.md)     | mark element to swap in from a response (out of band)                                                              |
| [`hx-target`](@/attributes/hx-target.md)         | specifies the target element to be swapped                                                                         |
| [`hx-trigger`](@/attributes/hx-trigger.md)       | specifies the event that triggers the request                                                                      |
| [`hx-vals`](@/attributes/hx-vals.md)             | add values to submit with the request (JSON format)                                                                |

</div>

## Additional Attribute Reference {#attributes-additional}

All other attributes available in htmx.

<div class="info-table">

| Attribute                                            | Description                                                                                                                        |
|------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------|
| [`hx-boost`](@/attributes/hx-boost.md)               | add [progressive enhancement](https://en.wikipedia.org/wiki/Progressive_enhancement) for links and forms                           |
| [`hx-confirm`](@/attributes/hx-confirm.md)           | shows a `confirm()` dialog before issuing a request                                                                                |
| [`hx-delete`](@/attributes/hx-delete.md)             | issues a `DELETE` to the specified URL                                                                                             |
| [`hx-disable`](@/attributes/hx-disable.md)           | disables htmx processing for the given node and any children nodes                                                                 |
| [`hx-disabled-elt`](@/attributes/hx-disabled-elt.md) | adds the `disabled` attribute to the specified elements while a request is in flight                                               |
| [`hx-disinherit`](@/attributes/hx-disinherit.md)     | control and disable automatic attribute inheritance for child nodes                                                                |
| [`hx-encoding`](@/attributes/hx-encoding.md)         | changes the request encoding type                                                                                                  |
| [`hx-ext`](@/attributes/hx-ext.md)                   | extensions to use for this element                                                                                                 |
| [`hx-headers`](@/attributes/hx-headers.md)           | adds to the headers that will be submitted with the request                                                                        |
| [`hx-history`](@/attributes/hx-history.md)           | prevent sensitive data being saved to the history cache                                                                            |
| [`hx-history-elt`](@/attributes/hx-history-elt.md)   | the element to snapshot and restore during history navigation                                                                      |
| [`hx-include`](@/attributes/hx-include.md)           | include additional data in requests                                                                                                |
| [`hx-indicator`](@/attributes/hx-indicator.md)       | the element to put the `htmx-request` class on during the request                                                                  |
| [`hx-inherit`](@/attributes/hx-inherit.md)           | control and enable automatic attribute inheritance for child nodes if it has been disabled by default                            |
| [`hx-params`](@/attributes/hx-params.md)             | filters the parameters that will be submitted with a request                                                                       |
| [`hx-patch`](@/attributes/hx-patch.md)               | issues a `PATCH` to the specified URL                                                                                              |
| [`hx-preserve`](@/attributes/hx-preserve.md)         | specifies elements to keep unchanged between requests                                                                              |
| [`hx-prompt`](@/attributes/hx-prompt.md)             | shows a `prompt()` before submitting a request                                                                                     |
| [`hx-put`](@/attributes/hx-put.md)                   | issues a `PUT` to the specified URL                                                                                                |
| [`hx-replace-url`](@/attributes/hx-replace-url.md)   | replace the URL in the browser location bar                                                                                        |
| [`hx-request`](@/attributes/hx-request.md)           | configures various aspects of the request                                                                                          |
| [`hx-sync`](@/attributes/hx-sync.md)                 | control how requests made by different elements are synchronized                                                                   |
| [`hx-validate`](@/attributes/hx-validate.md)         | force elements to validate themselves before a request                                                                             |
| [`hx-vars`](@/attributes/hx-vars.md)                 | adds values dynamically to the parameters to submit with the request (deprecated, please use [`hx-vals`](@/attributes/hx-vals.md)) |

</div>

## CSS Class Reference {#classes}

<div class="info-table">

| Class | Description |
|-----------|-------------|
| `htmx-added` | Applied to a new piece of content before it is swapped, removed after it is settled.
| `htmx-indicator` | A dynamically generated class that will toggle visible (opacity:1) when a `htmx-request` class is present
| `htmx-request` | Applied to either the element or the element specified with [`hx-indicator`](@/attributes/hx-indicator.md) while a request is ongoing
| `htmx-settling` | Applied to a target after content is swapped, removed after it is settled. The duration can be modified via [`hx-swap`](@/attributes/hx-swap.md).
| `htmx-swapping` | Applied to a target before any content is swapped, removed after it is swapped. The duration can be modified via [`hx-swap`](@/attributes/hx-swap.md).

</div>

## HTTP Header Reference {#headers}

### Request Headers Reference {#request_headers}

<div class="info-table">

| Header | Description |
|--------|-------------|
| `HX-Boosted` | indicates that the request is via an element using [hx-boost](@/attributes/hx-boost.md)
| `HX-Current-URL` | the current URL of the browser
| `HX-History-Restore-Request` | "true" if the request is for history restoration after a miss in the local history cache
| `HX-Prompt` | the user response to an [hx-prompt](@/attributes/hx-prompt.md)
| `HX-Request` | always "true"
| `HX-Target` | the `id` of the target element if it exists
| `HX-Trigger-Name` | the `name` of the triggered element if it exists
| `HX-Trigger` | the `id` of the triggered element if it exists

</div>

### Response Headers Reference {#response_headers}

<div class="info-table">

| Header                                               | Description |
|------------------------------------------------------|-------------|
| [`HX-Location`](@/headers/hx-location.md)            | allows you to do a client-side redirect that does not do a full page reload
| [`HX-Push-Url`](@/headers/hx-push-url.md)            | pushes a new url into the history stack
| [`HX-Redirect`](@/headers/hx-redirect.md)            | can be used to do a client-side redirect to a new location
| `HX-Refresh`                                         | if set to "true" the client-side will do a full refresh of the page
| [`HX-Replace-Url`](@/headers/hx-replace-url.md)      | replaces the current URL in the location bar
| `HX-Reswap`                                          | allows you to specify how the response will be swapped. See [hx-swap](@/attributes/hx-swap.md) for possible values
| `HX-Retarget`                                        | a CSS selector that updates the target of the content update to a different element on the page
| `HX-Reselect`                                        | a CSS selector that allows you to choose which part of the response is used to be swapped in. Overrides an existing [`hx-select`](@/attributes/hx-select.md) on the triggering element
| [`HX-Trigger`](@/headers/hx-trigger.md)              | allows you to trigger client-side events
| [`HX-Trigger-After-Settle`](@/headers/hx-trigger.md) | allows you to trigger client-side events after the settle step
| [`HX-Trigger-After-Swap`](@/headers/hx-trigger.md)   | allows you to trigger client-side events after the swap step

</div>

## Event Reference {#events}

<div class="info-table">

| Event | Description |
|-------|-------------|
| [`htmx:abort`](@/events.md#htmx:abort) | send this event to an element to abort a request
| [`htmx:afterOnLoad`](@/events.md#htmx:afterOnLoad) | triggered after an AJAX request has completed processing a successful response
| [`htmx:afterProcessNode`](@/events.md#htmx:afterProcessNode) | triggered after htmx has initialized a node
| [`htmx:afterRequest`](@/events.md#htmx:afterRequest)  | triggered after an AJAX request has completed
| [`htmx:afterSettle`](@/events.md#htmx:afterSettle)  | triggered after the DOM has settled
| [`htmx:afterSwap`](@/events.md#htmx:afterSwap)  | triggered after new content has been swapped in
| [`htmx:beforeCleanupElement`](@/events.md#htmx:beforeCleanupElement)  | triggered before htmx [disables](@/attributes/hx-disable.md) an element or removes it from the DOM
| [`htmx:beforeOnLoad`](@/events.md#htmx:beforeOnLoad)  | triggered before any response processing occurs
| [`htmx:beforeProcessNode`](@/events.md#htmx:beforeProcessNode) | triggered before htmx initializes a node
| [`htmx:beforeRequest`](@/events.md#htmx:beforeRequest)  | triggered before an AJAX request is made
| [`htmx:beforeSwap`](@/events.md#htmx:beforeSwap)  | triggered before a swap is done, allows you to configure the swap
| [`htmx:beforeSend`](@/events.md#htmx:beforeSend)  | triggered just before an ajax request is sent
| [`htmx:beforeTransition`](@/events.md#htmx:beforeTransition)  | triggered before the [View Transition](https://developer.mozilla.org/en-US/docs/Web/API/View_Transitions_API) wrapped swap occurs
| [`htmx:configRequest`](@/events.md#htmx:configRequest)  | triggered before the request, allows you to customize parameters, headers
| [`htmx:confirm`](@/events.md#htmx:confirm)  | triggered after a trigger occurs on an element, allows you to cancel (or delay) issuing the AJAX request
| [`htmx:historyCacheError`](@/events.md#htmx:historyCacheError)  | triggered on an error during cache writing
| [`htmx:historyCacheHit`](@/events.md#htmx:historyCacheHit)  | triggered on a cache hit in the history subsystem
| [`htmx:historyCacheMiss`](@/events.md#htmx:historyCacheMiss)  | triggered on a cache miss in the history subsystem
| [`htmx:historyCacheMissLoadError`](@/events.md#htmx:historyCacheMissLoadError)  | triggered on a unsuccessful remote retrieval
| [`htmx:historyCacheMissLoad`](@/events.md#htmx:historyCacheMissLoad)  | triggered on a successful remote retrieval
| [`htmx:historyRestore`](@/events.md#htmx:historyRestore)  | triggered when htmx handles a history restoration action
| [`htmx:beforeHistorySave`](@/events.md#htmx:beforeHistorySave)  | triggered before content is saved to the history cache
| [`htmx:load`](@/events.md#htmx:load)  | triggered when new content is added to the DOM
| [`htmx:noSSESourceError`](@/events.md#htmx:noSSESourceError)  | triggered when an element refers to a SSE event in its trigger, but no parent SSE source has been defined
| [`htmx:onLoadError`](@/events.md#htmx:onLoadError)  | triggered when an exception occurs during the onLoad handling in htmx
| [`htmx:oobAfterSwap`](@/events.md#htmx:oobAfterSwap)  | triggered after an out of band element as been swapped in
| [`htmx:oobBeforeSwap`](@/events.md#htmx:oobBeforeSwap)  | triggered before an out of band element swap is done, allows you to configure the swap
| [`htmx:oobErrorNoTarget`](@/events.md#htmx:oobErrorNoTarget)  | triggered when an out of band element does not have a matching ID in the current DOM
| [`htmx:prompt`](@/events.md#htmx:prompt)  | triggered after a prompt is shown
| [`htmx:pushedIntoHistory`](@/events.md#htmx:pushedIntoHistory)  | triggered after a url is pushed into history
| [`htmx:replacedInHistory`](@/events.md#htmx:replacedInHistory)  | triggered after a url is replaced in history
| [`htmx:responseError`](@/events.md#htmx:responseError)  | triggered when an HTTP response error (non-`200` or `300` response code) occurs
| [`htmx:sendAbort`](@/events.md#htmx:sendAbort)  | triggered when a request is aborted
| [`htmx:sendError`](@/events.md#htmx:sendError)  | triggered when a network error prevents an HTTP request from happening
| [`htmx:sseError`](@/events.md#htmx:sseError)  | triggered when an error occurs with a SSE source
| [`htmx:sseOpen`](/events#htmx:sseOpen)  | triggered when a SSE source is opened
| [`htmx:swapError`](@/events.md#htmx:swapError)  | triggered when an error occurs during the swap phase
| [`htmx:targetError`](@/events.md#htmx:targetError)  | triggered when an invalid target is specified
| [`htmx:timeout`](@/events.md#htmx:timeout)  | triggered when a request timeout occurs
| [`htmx:validation:validate`](@/events.md#htmx:validation:validate)  | triggered before an element is validated
| [`htmx:validation:failed`](@/events.md#htmx:validation:failed)  | triggered when an element fails validation
| [`htmx:validation:halted`](@/events.md#htmx:validation:halted)  | triggered when a request is halted due to validation errors
| [`htmx:xhr:abort`](@/events.md#htmx:xhr:abort)  | triggered when an ajax request aborts
| [`htmx:xhr:loadend`](@/events.md#htmx:xhr:loadend)  | triggered when an ajax request ends
| [`htmx:xhr:loadstart`](@/events.md#htmx:xhr:loadstart)  | triggered when an ajax request starts
| [`htmx:xhr:progress`](@/events.md#htmx:xhr:progress)  | triggered periodically during an ajax request that supports progress events

</div>

## JavaScript API Reference {#api}

<div class="info-table">

| Method | Description |
|-------|-------------|
| [`htmx.addClass()`](@/api.md#addClass)  | Adds a class to the given element
| [`htmx.ajax()`](@/api.md#ajax)  | Issues an htmx-style ajax request
| [`htmx.closest()`](@/api.md#closest)  | Finds the closest parent to the given element matching the selector
| [`htmx.config`](@/api.md#config)  | A property that holds the current htmx config object
| [`htmx.createEventSource`](@/api.md#createEventSource)  | A property holding the function to create SSE EventSource objects for htmx
| [`htmx.createWebSocket`](@/api.md#createWebSocket)  | A property holding the function to create WebSocket objects for htmx
| [`htmx.defineExtension()`](@/api.md#defineExtension)  | Defines an htmx [extension](https://htmx.org/extensions)
| [`htmx.find()`](@/api.md#find)  | Finds a single element matching the selector
| [`htmx.findAll()` `htmx.findAll(elt, selector)`](@/api.md#find)  | Finds all elements matching a given selector
| [`htmx.logAll()`](@/api.md#logAll)  | Installs a logger that will log all htmx events
| [`htmx.logger`](@/api.md#logger)  | A property set to the current logger (default is `null`)
| [`htmx.off()`](@/api.md#off)  | Removes an event listener from the given element
| [`htmx.on()`](@/api.md#on)  | Creates an event listener on the given element, returning it
| [`htmx.onLoad()`](@/api.md#onLoad)  | Adds a callback handler for the `htmx:load` event
| [`htmx.parseInterval()`](@/api.md#parseInterval)  | Parses an interval declaration into a millisecond value
| [`htmx.process()`](@/api.md#process)  | Processes the given element and its children, hooking up any htmx behavior
| [`htmx.remove()`](@/api.md#remove)  | Removes the given element
| [`htmx.removeClass()`](@/api.md#removeClass)  | Removes a class from the given element
| [`htmx.removeExtension()`](@/api.md#removeExtension)  | Removes an htmx [extension](https://htmx.org/extensions)
| [`htmx.swap()`](@/api.md#swap)  | Performs swapping (and settling) of HTML content
| [`htmx.takeClass()`](@/api.md#takeClass)  | Takes a class from other elements for the given element
| [`htmx.toggleClass()`](@/api.md#toggleClass)  | Toggles a class from the given element
| [`htmx.trigger()`](@/api.md#trigger)  | Triggers an event on an element
| [`htmx.values()`](@/api.md#values)  | Returns the input values associated with the given element

</div>


## Configuration Reference {#config}

Htmx has some configuration options that can be accessed either programmatically or declaratively.  They are
listed below:

<div class="info-table">

| Config Variable                        | Info                                                                                                                                                                       |
|----------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `htmx.config.historyEnabled`           | defaults to `true`, really only useful for testing                                                                                                                         |
| `htmx.config.historyCacheSize`         | defaults to 10                                                                                                                                                             |
| `htmx.config.refreshOnHistoryMiss`     | defaults to `false`, if set to `true` htmx will issue a full page refresh on history misses rather than use an AJAX request                                                |
| `htmx.config.defaultSwapStyle`         | defaults to `innerHTML`                                                                                                                                                    |
| `htmx.config.defaultSwapDelay`         | defaults to 0                                                                                                                                                              |
| `htmx.config.defaultSettleDelay`       | defaults to 20                                                                                                                                                             |
| `htmx.config.includeIndicatorStyles`   | defaults to `true` (determines if the indicator styles are loaded)                                                                                                         |
| `htmx.config.indicatorClass`           | defaults to `htmx-indicator`                                                                                                                                               |
| `htmx.config.requestClass`             | defaults to `htmx-request`                                                                                                                                                 |
| `htmx.config.addedClass`               | defaults to `htmx-added`                                                                                                                                                   |
| `htmx.config.settlingClass`            | defaults to `htmx-settling`                                                                                                                                                |
| `htmx.config.swappingClass`            | defaults to `htmx-swapping`                                                                                                                                                |
| `htmx.config.allowEval`                | defaults to `true`, can be used to disable htmx's use of eval for certain features (e.g. trigger filters)                                                                  |
| `htmx.config.allowScriptTags`          | defaults to `true`, determines if htmx will process script tags found in new content                                                                                       |
| `htmx.config.inlineScriptNonce`        | defaults to `''`, meaning that no nonce will be added to inline scripts                                                                                                    |
| `htmx.config.inlineStyleNonce`         | defaults to `''`, meaning that no nonce will be added to inline styles                                                                                                     |
| `htmx.config.attributesToSettle`       | defaults to `["class", "style", "width", "height"]`, the attributes to settle during the settling phase                                                                    |
| `htmx.config.wsReconnectDelay`         | defaults to `full-jitter`                                                                                                                                                  |
| `htmx.config.wsBinaryType`             | defaults to `blob`, the [the type of binary data](https://developer.mozilla.org/docs/Web/API/WebSocket/binaryType) being received over the WebSocket connection            |
| `htmx.config.disableSelector`          | defaults to `[hx-disable], [data-hx-disable]`, htmx will not process elements with this attribute on it or a parent                                                        |
| `htmx.config.disableInheritance`       | defaults to `false`. If it is set to `true`, the inheritance of attributes is completely disabled and you can explicitly specify the inheritance with the [hx-inherit](@/attributes/hx-inherit.md) attribute.
| `htmx.config.withCredentials`          | defaults to `false`, allow cross-site Access-Control requests using credentials such as cookies, authorization headers or TLS client certificates                          |
| `htmx.config.timeout`                  | defaults to 0, the number of milliseconds a request can take before automatically being terminated                                                                         |
| `htmx.config.scrollBehavior`           | defaults to 'instant', the scroll behavior when using the [show](@/attributes/hx-swap.md#scrolling-scroll-show) modifier with `hx-swap`. The allowed values are `instant` (scrolling should happen instantly in a single jump), `smooth` (scrolling should animate smoothly) and `auto` (scroll behavior is determined by the computed value of [scroll-behavior](https://developer.mozilla.org/en-US/docs/Web/CSS/scroll-behavior)). |
| `htmx.config.defaultFocusScroll`       | if the focused element should be scrolled into view, defaults to false and can be overridden using the [focus-scroll](@/attributes/hx-swap.md#focus-scroll) swap modifier. |
| `htmx.config.getCacheBusterParam`      | defaults to false, if set to true htmx will append the target element to the `GET` request in the format `org.htmx.cache-buster=targetElementId`                           |
| `htmx.config.globalViewTransitions`    | if set to `true`, htmx will use the [View Transition](https://developer.mozilla.org/en-US/docs/Web/API/View_Transitions_API) API when swapping in new content.             |
| `htmx.config.methodsThatUseUrlParams`  | defaults to `["get", "delete"]`, htmx will format requests with these methods by encoding their parameters in the URL, not the request body                                |
| `htmx.config.selfRequestsOnly`         | defaults to `true`, whether to only allow AJAX requests to the same domain as the current document                                                             |
| `htmx.config.ignoreTitle`              | defaults to `false`, if set to `true` htmx will not update the title of the document when a `title` tag is found in new content                                            |
| `htmx.config.scrollIntoViewOnBoost`    | defaults to `true`, whether or not the target of a boosted element is scrolled into the viewport. If `hx-target` is omitted on a boosted element, the target defaults to `body`, causing the page to scroll to the top. |
| `htmx.config.triggerSpecsCache`        | defaults to `null`, the cache to store evaluated trigger specifications into, improving parsing performance at the cost of more memory usage. You may define a simple object to use a never-clearing cache, or implement your own system using a [proxy object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Proxy) |
| `htmx.config.responseHandling`         | the default [Response Handling](@/docs.md#response-handling) behavior for response status codes can be configured here to either swap or error                             |
| `htmx.config.allowNestedOobSwaps`      | defaults to `true`, whether to process OOB swaps on elements that are nested within the main response element. See [Nested OOB Swaps](@/attributes/hx-swap-oob.md#nested-oob-swaps). |
| `htmx.config.historyRestoreAsHxRequest`| defaults to `true`, Whether to treat history cache miss full page reload requests as a "HX-Request" by returning this response header. This should always be disabled when using HX-Request header to optionally return partial responses                                                                                                         |


</div>

You can set them directly in javascript, or you can use a `meta` tag:

```html
<meta name="htmx-config" content='{"defaultSwapStyle":"outerHTML"}'>
```</doc><doc title="Starlette quick guide" desc="A quick overview of some Starlette features useful to FastHTML devs."># 🌟 Starlette Quick Manual


2020-02-09

Starlette is the ASGI web framework used as the foundation of FastHTML. Listed here are some Starlette features FastHTML developers can use directly, since the `FastHTML` class inherits from the `Starlette` class (but note that FastHTML has its own customised `RouteX` and `RouterX` classes for routing, to handle FT element trees etc).

## Get uploaded file content

```
async def handler(request):
    inp = await request.form()
    uploaded_file = inp["filename"]
    filename = uploaded_file.filename           # abc.png
    content_type = uploaded.content_type    # MIME type, e.g. image/png
    content = await uploaded_file.read()       # image content

```

## Return a customized response (status code and headers)

```
import json
from starlette.responses import Response

async def handler(request):
    data = {
        "name": "Bo"
    }
    return Response(json.dumps(data), media_type="application/json")

```

`Response` takes `status_code`, `headers` and `media_type`, so if we want to change a response's status code, we can do:

```
return Response(content, statu_code=404)

```

And customized headers:

```
headers = {
	"x-extra-key": "value"
}
return Response(content, status_code=200, headers=headers)

```

## Redirect

```
from starlette.responses import RedirectResponse

async handler(request):
    # Customize status_code: 
    #   301: permanent redirect 
    #   302: temporary redirect 
    #   303: see others
    #   307: temporary redirect (default)
    return RedirectResponse(url=url, status_code=303)

```

## Request context

### URL Object: `request.url`

  * Get request full url: `url = str(request.url)`
  * Get scheme: `request.url.scheme` (http, https, ws, wss)
  * Get netloc: `request.url.netloc`, e.g.: example.com:8080
  * Get path: `request.url.path`, e.g.: /search
  * Get query string: `request.url.query`, e.g.: kw=hello
  * Get hostname: `request.url.hostname`, e.g.: example.com
  * Get port: `request.url.port`, e.g.: 8080
  * If using secure scheme: `request.url.is_secure`, True is schme is `https` or `wss`

### Headers: `request.headers`

```
{
    'host': 'example.com:8080', 
    'connection': 'keep-alive', 
    'cache-control': 'max-age=0', 
    'sec-ch-ua': 'Google Chrome 80', 
    'dnt': '1', 
    'upgrade-insecure-requests': '1', 
    'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) ...',
    'sec-fetch-dest': 'document', 
    'accept': 'text/html,image/apng,*/*;q=0.8;v=b3;q=0.9', 
    'sec-origin-policy': '0', 
    'sec-fetch-site': 'none', 
    'sec-fetch-mode': 'navigate', 
    'sec-fetch-user': '?1', 
    'accept-encoding': 'gzip, deflate, br', 
    'accept-language': 'en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7,zh-TW;q=0.6', 
    'cookie': 'session=eyJhZG1pbl91c2_KiQ...'
}

```

### Client: `request.client`

  * `request.client.host`: get client sock IP
  * `request.client.port`: get client sock port

### Method: `request.method`

  * `request.method`: GET, POST, etc.

### Get Data

  * `await request.body()`: get raw data from body
  * `await request.json()`: get passed data and parse it as JSON
  * `await request.form()`: get posted data and pass it as dictionary

### Scope: `request.scope`

```
{
    'type': 'http', 
    'http_version': '1.1', 
    'server': ('127.0.0.1', 9092), 
    'client': ('127.0.0.1', 53102), 
    'scheme': 'https', 
    'method': 'GET', 
    'root_path': '', 
    'path': '/', 
    'raw_path': b'/', 
    'query_string': b'kw=hello', 
    'headers': [
        (b'host', b'example.com:8080'), 
        (b'connection', b'keep-alive'), 
        (b'cache-control', b'max-age=0'), 
        ...
    ], 
    'app': <starlette.applications.Starlette object at 0x1081bd650>, 
    'session': {'uid': '57ba03ea7333f72a25f837cf'}, 
    'router': <starlette.routing.Router object at 0x1081bd6d0>, 
    'endpoint': <class 'app.index.Index'>, 
    'path_params': {}
}

```

## Put varaible in request & app scope

```
app.state.dbconn = get_db_conn()
request.state.start_time = time.time()
# use app-scope state variable in a request
request.app.state.dbconn

```

## Utility functions

### Use `State` to wrap a dictionary

```
from starlette.datastructures import State

data = {
    "name": "Bo"
}
print(data["name"])
# now wrap it with State function
wrapped = State(data)
# You can use the dot syntaxt, but can't use `wrapped["name"]` any more.
print(wrapped.name)

```

### login_required wrapper function

NB: This is easier to do in FastHTML using Beforeware.

```
import functools
from starlette.endpoints import HTTPEndpoint
from starlette.responses import Response

def login_required(login_url="/signin"):
    def decorator(handler):
        @functools.wraps(handler)
        async def new_handler(obj, req, *args, **kwargs):
            user = req.session.get("login_user")
            if user is None:
                return seeother(login_url)
            return await handler(obj, req, *args, **kwargs)
        return new_handler
    return decorator

class MyAccount(HTTPEndpiont):
    @login_required()
    async def get(self, request):
        # some logic here
        content = "hello"
        return Response(content)

```

## Exceptions

Handle exception and customize 403, 404, 503, 500 page:

```
from starlette.exceptions import HTTPException

async def exc_handle_403(request, exc):
    return HTMLResponse("My 403 page", status_code=exc.status_code)

async def exc_handle_404(request, exc):
    return HTMLResponse("My 404 page", status_code=exc.status_code)

async def exc_handle_503(request, exc):
    return HTMLResponse("Failed, please try it later", status_code=exc.status_code)

# error is not exception, 500 is server side unexpected error, all other status code will be treated as Exception
async def err_handle_500(request, exc):
    import traceback
    Log.error(traceback.format_exc())
    return HTMLResponse("My 500 page", status_code=500)

# To add handler, we can add either status_code or Exception itself as key
exception_handlers = {
    403: exc_handle_403,
    404: exc_handle_404,
    503: exc_handle_503,
    500: err_handle_500,
    #HTTPException: exc_handle_500,
}

app = Starlette(routes=routes, exception_handlers=exception_handlers)

```

## Background Task

### Put some async task as background task

```
import aiofiles
from starlette.background import BackgroundTask
from starlette.responses import Response

aiofiles_remove = aiofiles.os.wrap(os.remove)

async def del_file(fpath):
    await aiofiles_remove(fpath)

async def handler(request):
    content = ""
    fpath = "/tmp/tmpfile.txt"
    task = BackgroundTask(del_file, fpath=fpath)
    return Response(content, background=task)

```

### Put multiple tasks as background task

```
from starlette.background import BackgroundTasks

async def task1(name):
    pass

async def task2(email):
    pass

async def handler(request):
    tasks = BackgroundTasks()
    tasks.add_task(task1, name="John")
    tasks.add_task(task2, email="info@example.com")
    content = ""
    return Response(content, background=tasks)

```

## Write middleware

There are 2 ways to write middleware:

### Define `__call__` function:

```
class MyMiddleware:
    def __init__(self, app):
        self.app = app

    async def __call__(self, scope, receive, send):
        # see above scope dictionary as reference
        headers = dict(scope["headers"])
        # do something
        # pass to next middleware
        return await self.app(scope, receive, send)

```

### Use `BaseHTTPMiddleware`

```
from starlette.middleware.base import BaseHTTPMiddleware

class CustomHeaderMiddleware(BaseHTTPMiddleware):
    async def dispatch(self, request, call_next):
        # do something before pass to next middleware
        response = await call_next(request)
        # do something after next middleware returned
        response.headers['X-Author'] = 'John'
        return response

```</doc></docs><api><doc title="API List" desc="A succint list of all functions and methods in fasthtml."># fasthtml Module Documentation

## fasthtml.authmw

- `class BasicAuthMiddleware`
    - `def __init__(self, app, cb, skip)`
    - `def __call__(self, scope, receive, send)`
    - `def authenticate(self, conn)`

## fasthtml.cli

- `@call_parse def railway_link()`
    Link the current directory to the current project's Railway service

- `@call_parse def railway_deploy(name, mount)`
    Deploy a FastHTML app to Railway

## fasthtml.components

> `ft_html` and `ft_hx` functions to add some conveniences to `ft`, along with a full set of basic HTML components, and functions to work with forms and `FT` conversion

- `def File(fname)`
    Use the unescaped text in file `fname` directly

- `def show(ft, *rest)`
    Renders FT Components into HTML within a Jupyter notebook.

- `def fill_form(form, obj)`
    Fills named items in `form` using attributes in `obj`

- `def fill_dataclass(src, dest)`
    Modifies dataclass in-place and returns it

- `def find_inputs(e, tags, **kw)`
    Recursively find all elements in `e` with `tags` and attrs matching `kw`

- `def html2ft(html, attr1st)`
    Convert HTML to an `ft` expression

- `def sse_message(elm, event)`
    Convert element `elm` into a format suitable for SSE streaming

## fasthtml.core

> The `FastHTML` subclass of `Starlette`, along with the `RouterX` and `RouteX` classes it automatically uses.

- `def parsed_date(s)`
    Convert `s` to a datetime

- `def snake2hyphens(s)`
    Convert `s` from snake case to hyphenated and capitalised

- `@dataclass class HtmxHeaders`
    - `def __bool__(self)`
    - `def __init__(self, boosted, current_url, history_restore_request, prompt, request, target, trigger_name, trigger)`

- `@dataclass class HttpHeader`
    - `def __init__(self, k, v)`

- `@use_kwargs_dict(**htmx_resps) def HtmxResponseHeaders(**kwargs)`
    HTMX response headers

- `def form2dict(form)`
    Convert starlette form data to a dict

- `def parse_form(req)`
    Starlette errors on empty multipart forms, so this checks for that situation

- `class JSONResponse`
    Same as starlette's version, but auto-stringifies non serializable types

    - `def render(self, content)`

- `def flat_xt(lst)`
    Flatten lists

- `class Beforeware`
    - `def __init__(self, f, skip)`

- `def EventStream(s)`
    Create a text/event-stream response from `s`

- `def flat_tuple(o)`
    Flatten lists

- `def noop_body(c, req)`
    Default Body wrap function which just returns the content

- `def respond(req, heads, bdy)`
    Default FT response creation function

- `class Redirect`
    Use HTMX or Starlette RedirectResponse as required to redirect to `loc`

    - `def __init__(self, loc)`
    - `def __response__(self, req)`

- `def qp(p, **kw)`
    Add parameters kw to path p

- `def def_hdrs(htmx, surreal)`
    Default headers for a FastHTML app

- `class FastHTML`
    - `def __init__(self, debug, routes, middleware, title, exception_handlers, on_startup, on_shutdown, lifespan, hdrs, ftrs, exts, before, after, surreal, htmx, default_hdrs, sess_cls, secret_key, session_cookie, max_age, sess_path, same_site, sess_https_only, sess_domain, key_fname, body_wrap, htmlkw, nb_hdrs, canonical, **bodykw)`

- `@patch def ws(self, path, conn, disconn, name, middleware)`
    Add a websocket route at `path`

- `def nested_name(f)`
    Get name of function `f` using '_' to join nested function names

- `@patch def route(self, path, methods, name, include_in_schema, body_wrap)`
    Add a route at `path`

- `def serve(appname, app, host, port, reload, reload_includes, reload_excludes)`
    Run the app in an async server, with live reload set as the default.

- `class Client`
    A simple httpx ASGI client that doesn't require `async`

    - `def __init__(self, app, url)`

- `class RouteFuncs`
    - `def __init__(self)`
    - `def __setattr__(self, name, value)`
    - `def __getattr__(self, name)`
    - `def __dir__(self)`

- `class APIRouter`
    Add routes to an app

    - `def __init__(self, prefix, body_wrap)`
    - `def __call__(self, path, methods, name, include_in_schema, body_wrap)`
        Add a route at `path`

    - `def __getattr__(self, name)`
    - `def to_app(self, app)`
        Add routes to `app`

    - `def ws(self, path, conn, disconn, name, middleware)`
        Add a websocket route at `path`


- `def cookie(key, value, max_age, expires, path, domain, secure, httponly, samesite)`
    Create a 'set-cookie' `HttpHeader`

- `@patch def static_route_exts(self, prefix, static_path, exts)`
    Add a static route at URL path `prefix` with files from `static_path` and `exts` defined by `reg_re_param()`

- `@patch def static_route(self, ext, prefix, static_path)`
    Add a static route at URL path `prefix` with files from `static_path` and single `ext` (including the '.')

- `class MiddlewareBase`
    - `def __call__(self, scope, receive, send)`

- `class FtResponse`
    Wrap an FT response with any Starlette `Response`

    - `def __init__(self, content, status_code, headers, cls, media_type, background)`
    - `def __response__(self, req)`

## fasthtml.fastapp

> The `fast_app` convenience wrapper

- `def fast_app(db_file, render, hdrs, ftrs, tbls, before, middleware, live, debug, title, routes, exception_handlers, on_startup, on_shutdown, lifespan, default_hdrs, pico, surreal, htmx, exts, canonical, secret_key, key_fname, session_cookie, max_age, sess_path, same_site, sess_https_only, sess_domain, htmlkw, bodykw, reload_attempts, reload_interval, static_path, body_wrap, nb_hdrs, **kwargs)`
    Create a FastHTML or FastHTMLWithLiveReload app.

## fasthtml.js

> Basic external Javascript lib wrappers

- `def light_media(css)`
    Render light media for day mode views

- `def dark_media(css)`
    Render dark media for night mode views

- `def MarkdownJS(sel)`
    Implements browser-based markdown rendering.

- `def HighlightJS(sel, langs, light, dark)`
    Implements browser-based syntax highlighting. Usage example [here](/tutorials/quickstart_for_web_devs.html#code-highlighting).

- `def MermaidJS(sel, theme)`
    Implements browser-based Mermaid diagram rendering.

## fasthtml.jupyter

> Use FastHTML in Jupyter notebooks

- `def nb_serve(app, log_level, port, host, **kwargs)`
    Start a Jupyter compatible uvicorn server with ASGI `app` on `port` with `log_level`

- `def nb_serve_async(app, log_level, port, host, **kwargs)`
    Async version of `nb_serve`

- `def is_port_free(port, host)`
    Check if `port` is free on `host`

- `def wait_port_free(port, host, max_wait)`
    Wait for `port` to be free on `host`

- `class JupyUvi`
    Start and stop a Jupyter compatible uvicorn server with ASGI `app` on `port` with `log_level`

    - `def __init__(self, app, log_level, host, port, start, **kwargs)`
    - `def start(self)`
    - `def start_async(self)`
    - `def stop(self)`

- `class JupyUviAsync`
    Start and stop an async Jupyter compatible uvicorn server with ASGI `app` on `port` with `log_level`

    - `def __init__(self, app, log_level, host, port, **kwargs)`
    - `def start(self)`
    - `def stop(self)`

- `def HTMX(path, host, app, port, height, link, iframe)`
    An iframe which displays the HTMX application in a notebook.

## fasthtml.live_reload

- `class FastHTMLWithLiveReload`
    `FastHTMLWithLiveReload` enables live reloading.
    This means that any code changes saved on the server will automatically
    trigger a reload of both the server and browser window.

    How does it work?
      - a websocket is created at `/live-reload`
      - a small js snippet `LIVE_RELOAD_SCRIPT` is injected into each webpage
      - this snippet connects to the websocket at `/live-reload` and listens for an `onclose` event
      - when the `onclose` event is detected the browser is reloaded

    Why do we listen for an `onclose` event?
      When code changes are saved the server automatically reloads if the --reload flag is set.
      The server reload kills the websocket connection. The `onclose` event serves as a proxy
      for "developer has saved some changes".

    Usage
        >>> from fasthtml.common import *
        >>> app = FastHTMLWithLiveReload()

        Run:
            serve()

    - `def __init__(self, *args, **kwargs)`

## fasthtml.oauth

> Basic scaffolding for handling OAuth

- `class GoogleAppClient`
    A `WebApplicationClient` for Google oauth2

    - `def __init__(self, client_id, client_secret, code, scope, project_id, **kwargs)`
    - `@classmethod def from_file(cls, fname, code, scope, **kwargs)`

- `class GitHubAppClient`
    A `WebApplicationClient` for GitHub oauth2

    - `def __init__(self, client_id, client_secret, code, scope, **kwargs)`

- `class HuggingFaceClient`
    A `WebApplicationClient` for HuggingFace oauth2

    - `def __init__(self, client_id, client_secret, code, scope, state, **kwargs)`

- `class DiscordAppClient`
    A `WebApplicationClient` for Discord oauth2

    - `def __init__(self, client_id, client_secret, is_user, perms, scope, **kwargs)`
    - `def login_link(self, redirect_uri, scope, state)`
    - `def parse_response(self, code, redirect_uri)`

- `class Auth0AppClient`
    A `WebApplicationClient` for Auth0 OAuth2

    - `def __init__(self, domain, client_id, client_secret, code, scope, redirect_uri, **kwargs)`
    - `def login_link(self, req)`

- `@patch def login_link(self, redirect_uri, scope, state, **kwargs)`
    Get a login link for this client

- `def redir_url(request, redir_path, scheme)`
    Get the redir url for the host in `request`

- `@patch def parse_response(self, code, redirect_uri)`
    Get the token from the oauth2 server response

- `@patch def get_info(self, token)`
    Get the info for authenticated user

- `@patch def retr_info(self, code, redirect_uri)`
    Combines `parse_response` and `get_info`

- `@patch def retr_id(self, code, redirect_uri)`
    Call `retr_info` and then return id/subscriber value

- `class OAuth`
    - `def __init__(self, app, cli, skip, redir_path, error_path, logout_path, login_path, https, http_patterns)`
    - `def redir_login(self, session)`
    - `def redir_url(self, req)`
    - `def login_link(self, req, scope, state)`
    - `def check_invalid(self, req, session, auth)`
    - `def logout(self, session)`
    - `def get_auth(self, info, ident, session, state)`

- `@patch() def consent_url(self, proj)`
    Get Google OAuth consent screen URL

- `@patch def save(self, fname)`
    Save credentials to `fname`

- `def load_creds(fname)`
    Load credentials from `fname`

- `@patch def creds(self)`
    Create `Credentials` from the client, refreshing if needed

## fasthtml.pico

> Basic components for generating Pico CSS tags

- `@delegates(ft_hx, keep=True) def Card(*c, **kwargs)`
    A PicoCSS Card, implemented as an Article with optional Header and Footer

- `@delegates(ft_hx, keep=True) def Group(*c, **kwargs)`
    A PicoCSS Group, implemented as a Fieldset with role 'group'

- `@delegates(ft_hx, keep=True) def Search(*c, **kwargs)`
    A PicoCSS Search, implemented as a Form with role 'search'

- `@delegates(ft_hx, keep=True) def Grid(*c, **kwargs)`
    A PicoCSS Grid, implemented as child Divs in a Div with class 'grid'

- `@delegates(ft_hx, keep=True) def DialogX(*c, **kwargs)`
    A PicoCSS Dialog, with children inside a Card

- `@delegates(ft_hx, keep=True) def Container(*args, **kwargs)`
    A PicoCSS Container, implemented as a Main with class 'container'

## fasthtml.stripe_otp

- `def create_price(app_nm, amt, currency)`
    Create a product and bind it to a price object. If product already exist just return the price list.

- `def archive_price(app_nm)`
    Archive a price - useful for cleanup if testing.

- `class Payment`

## fasthtml.svg

> Simple SVG FT elements

- `def Svg(*args, **kwargs)`
    An SVG tag; xmlns is added automatically, and viewBox defaults to height and width if not provided

- `@delegates(ft_hx) def ft_svg(tag, *c, **kwargs)`
    Create a standard `FT` element with some SVG-specific attrs

- `@delegates(ft_svg) def Rect(width, height, x, y, fill, stroke, stroke_width, rx, ry, **kwargs)`
    A standard SVG `rect` element

- `@delegates(ft_svg) def Circle(r, cx, cy, fill, stroke, stroke_width, **kwargs)`
    A standard SVG `circle` element

- `@delegates(ft_svg) def Ellipse(rx, ry, cx, cy, fill, stroke, stroke_width, **kwargs)`
    A standard SVG `ellipse` element

- `def transformd(translate, scale, rotate, skewX, skewY, matrix)`
    Create an SVG `transform` kwarg dict

- `@delegates(ft_svg) def Line(x1, y1, x2, y2, stroke, w, stroke_width, **kwargs)`
    A standard SVG `line` element

- `@delegates(ft_svg) def Polyline(*args, **kwargs)`
    A standard SVG `polyline` element

- `@delegates(ft_svg) def Polygon(*args, **kwargs)`
    A standard SVG `polygon` element

- `@delegates(ft_svg) def Text(*args, **kwargs)`
    A standard SVG `text` element

- `class PathFT`
    - `def M(self, x, y)`
        Move to.

    - `def L(self, x, y)`
        Line to.

    - `def H(self, x)`
        Horizontal line to.

    - `def V(self, y)`
        Vertical line to.

    - `def Z(self)`
        Close path.

    - `def C(self, x1, y1, x2, y2, x, y)`
        Cubic Bézier curve.

    - `def S(self, x2, y2, x, y)`
        Smooth cubic Bézier curve.

    - `def Q(self, x1, y1, x, y)`
        Quadratic Bézier curve.

    - `def T(self, x, y)`
        Smooth quadratic Bézier curve.

    - `def A(self, rx, ry, x_axis_rotation, large_arc_flag, sweep_flag, x, y)`
        Elliptical Arc.


- `def SvgOob(*args, **kwargs)`
    Wraps an SVG shape as required for an HTMX OOB swap

- `def SvgInb(*args, **kwargs)`
    Wraps an SVG shape as required for an HTMX inband swap

## fasthtml.xtend

> Simple extensions to standard HTML components, such as adding sensible defaults

- `@delegates(ft_hx, keep=True) def A(*c, **kwargs)`
    An A tag; `href` defaults to '#' for more concise use with HTMX

- `@delegates(ft_hx, keep=True) def AX(txt, hx_get, target_id, hx_swap, href, **kwargs)`
    An A tag with just one text child, allowing hx_get, target_id, and hx_swap to be positional params

- `@delegates(ft_hx, keep=True) def Form(*c, **kwargs)`
    A Form tag; identical to plain `ft_hx` version except default `enctype='multipart/form-data'`

- `@delegates(ft_hx, keep=True) def Hidden(value, id, **kwargs)`
    An Input of type 'hidden'

- `@delegates(ft_hx, keep=True) def CheckboxX(checked, label, value, id, name, **kwargs)`
    A Checkbox optionally inside a Label, preceded by a `Hidden` with matching name

- `@delegates(ft_html, keep=True) def Script(code, **kwargs)`
    A Script tag that doesn't escape its code

- `@delegates(ft_html, keep=True) def Style(*c, **kwargs)`
    A Style tag that doesn't escape its code

- `def double_braces(s)`
    Convert single braces to double braces if next to special chars or newline

- `def undouble_braces(s)`
    Convert double braces to single braces if next to special chars or newline

- `def loose_format(s, **kw)`
    String format `s` using `kw`, without being strict about braces outside of template params

- `def ScriptX(fname, src, nomodule, type, _async, defer, charset, crossorigin, integrity, **kw)`
    A `script` element with contents read from `fname`

- `def replace_css_vars(css, pre, **kwargs)`
    Replace `var(--)` CSS variables with `kwargs` if name prefix matches `pre`

- `def StyleX(fname, **kw)`
    A `style` element with contents read from `fname` and variables replaced from `kw`

- `def Nbsp()`
    A non-breaking space

- `def Surreal(code)`
    Wrap `code` in `domReadyExecute` and set `m=me()` and `p=me('-')`

- `def On(code, event, sel, me)`
    An async surreal.js script block event handler for `event` on selector `sel,p`, making available parent `p`, event `ev`, and target `e`

- `def Prev(code, event)`
    An async surreal.js script block event handler for `event` on previous sibling, with same vars as `On`

- `def Now(code, sel)`
    An async surreal.js script block on selector `me(sel)`

- `def AnyNow(sel, code)`
    An async surreal.js script block on selector `any(sel)`

- `def run_js(js, id, **kw)`
    Run `js` script, auto-generating `id` based on name of caller if needed, and js-escaping any `kw` params

- `def jsd(org, repo, root, path, prov, typ, ver, esm, **kwargs)`
    jsdelivr `Script` or CSS `Link` tag, or URL

- `class Fragment`
    An empty tag, used as a container

    - `def __init__(self, *c)`

- `@delegates(ft_hx, keep=True) def Titled(title, *args, **kwargs)`
    An HTML partial containing a `Title`, and `H1`, and any provided children

- `def Socials(title, site_name, description, image, url, w, h, twitter_site, creator, card)`
    OG and Twitter social card headers

- `def YouTubeEmbed(video_id, **kwargs)`
    Embed a YouTube video

- `def Favicon(light_icon, dark_icon)`
    Light and dark favicon headers
</doc><doc title="MonsterUI API List" desc="Complete API Reference for Monster UI, a component framework similar to shadcn, but for FastHTML"># monsterui Module Documentation

## monsterui.core

- `class ThemeRadii(Enum)`
    Members: none, sm, md, lg


- `class ThemeShadows`

- `class ThemeFont`

- `class Theme(Enum)`
    Selector to choose theme and get all headers needed for app.  Includes frankenui + tailwind + daisyui + highlight.js options
    Members: slate, stone, gray, neutral, red, rose, orange, green, blue, yellow, violet, zinc

    - `headers(self, mode, icons, daisy, highlightjs, katex, apex_charts, radii, shadows, font)`
        Create frankenui and tailwind cdns

    - `local_headers(self, mode, static_dir, icons, daisy, highlightjs, katex, apex_charts, radii, shadows, font)`
        Create headers using local files downloaded from CDNs


## monsterui.daisy

- `class AlertT(Enum)`
    Alert styles from DaisyUI
    Members: info, success, warning, error


- `def Alert(*c, **kwargs)`
    Alert informs users about important events.

- `class StepsT(Enum)`
    Options for Steps
    Members: vertical, horizonal


- `class StepT(Enum)`
    Step styles for LiStep
    Members: primary, secondary, accent, info, success, warning, error, neutral


- `def Steps(*li, **kwargs)`
    Creates a steps container

- `def LiStep(*c, **kwargs)`
    Creates a step list item

- `class LoadingT(Enum)`
    Members: spinner, dots, ring, ball, bars, infinity, xs, sm, md, lg


- `def Loading(cls, htmx_indicator, **kwargs)`
    Creates a loading animation component

- `class ToastHT(Enum)`
    Horizontal position for Toast
    Members: start, center, end


- `class ToastVT(Enum)`
    Vertical position for Toast
    Members: top, middle, bottom


## monsterui.foundations

> Data Structures and Utilties

- `def stringify(o)`
    Converts input types into strings that can be passed to FT components

- `class VEnum(Enum)`
    Members: 

    - `__str__(self)`
    - `__add__(self, other)`
    - `__radd__(self, other)`

## monsterui.franken

- `class TextT(Enum)`
    Text Styles from https://franken-ui.dev/docs/text
    Members: paragraph, lead, meta, gray, italic, xs, sm, lg, xl, light, normal, medium, bold, extrabold, muted, primary, secondary, success, warning, error, info, left, right, center, justify, start, end, top, middle, bottom, truncate, break_, nowrap, underline, highlight


- `class TextPresets(Enum)`
    Common Typography Presets
    Members: muted_sm, muted_lg, bold_sm, bold_lg, md_weight_sm, md_weight_muted


- `def CodeSpan(*c, **kwargs)`
    A CodeSpan with Styling

- `def CodeBlock(*c, **kwargs)`
    CodeBlock with Styling

- `def H1(*c, **kwargs)`
    H1 with styling and appropriate size

- `def H2(*c, **kwargs)`
    H2 with styling and appropriate size

- `def H3(*c, **kwargs)`
    H3 with styling and appropriate size

- `def H4(*c, **kwargs)`
    H4 with styling and appropriate size

- `def H5(*c, **kwargs)`
    H5 with styling and appropriate size

- `def H6(*c, **kwargs)`
    H6 with styling and appropriate size

- `def Subtitle(*c, **kwargs)`
    Styled muted_sm text designed to go under Headings and Titles

- `def Q(*c, **kwargs)`
    Styled quotation mark

- `def Em(*c, **kwargs)`
    Styled emphasis text

- `def Strong(*c, **kwargs)`
    Styled strong text

- `def I(*c, **kwargs)`
    Styled italic text

- `def Small(*c, **kwargs)`
    Styled small text

- `def Mark(*c, **kwargs)`
    Styled highlighted text

- `def Del(*c, **kwargs)`
    Styled deleted text

- `def Ins(*c, **kwargs)`
    Styled inserted text

- `def Sub(*c, **kwargs)`
    Styled subscript text

- `def Sup(*c, **kwargs)`
    Styled superscript text

- `def Blockquote(*c, **kwargs)`
    Blockquote with Styling

- `def Caption(*c, **kwargs)`
    Styled caption text

- `def Cite(*c, **kwargs)`
    Styled citation text

- `def Time(*c, **kwargs)`
    Styled time element

- `def Address(*c, **kwargs)`
    Styled address element

- `def Abbr(*c, **kwargs)`
    Styled abbreviation with dotted underline

- `def Dfn(*c, **kwargs)`
    Styled definition term with italic and medium weight

- `def Kbd(*c, **kwargs)`
    Styled keyboard input with subtle background

- `def Samp(*c, **kwargs)`
    Styled sample output with subtle background

- `def Var(*c, **kwargs)`
    Styled variable with italic monospace

- `def Figure(*c, **kwargs)`
    Styled figure container with card-like appearance

- `def Details(*c, **kwargs)`
    Styled details element

- `def Summary(*c, **kwargs)`
    Styled summary element

- `def Data(*c, **kwargs)`
    Styled data element

- `def Meter(*c, **kwargs)`
    Styled meter element

- `def S(*c, **kwargs)`
    Styled strikethrough text (different semantic meaning from Del)

- `def U(*c, **kwargs)`
    Styled underline (for proper names in Chinese, proper spelling etc)

- `def Output(*c, **kwargs)`
    Styled output element for form results

- `def PicSumImg(h, w, id, grayscale, blur, **kwargs)`
    Creates a placeholder image using https://picsum.photos/

- `def AccordionItem(title, *c)`
    Creates a single item for use within an Accordion component, handling title, content, and open state.

- `def Accordion(*c, **kwargs)`
    Creates a styled Accordion container using accordion component.

- `class ButtonT(Enum)`
    Options for styling Buttons
    Members: default, ghost, primary, secondary, destructive, text, link, xs, sm, lg, xl, icon


- `def Button(*c, **kwargs)`
    Button with Styling (defaults to `submit` for form submission)

- `class ContainerT(Enum)`
    Max width container sizes from https://franken-ui.dev/docs/container
    Members: xs, sm, lg, xl, expand


- `class BackgroundT(Enum)`
    Members: muted, primary, secondary, default


- `def Container(*c, **kwargs)`
    Div to be used as a container that often wraps large sections or a page of content

- `def Titled(title, *c, **kwargs)`
    Creates a standard page structure for titled page.  Main(Container(title, content))

- `class DividerT(Enum)`
    Divider Styles from https://franken-ui.dev/docs/divider
    Members: icon, sm, vertical


- `def Divider(*c, **kwargs)`
    Divider with default styling and margin

- `def DividerSplit(*c)`
    Creates a simple horizontal line divider with configurable thickness and vertical spacing

- `def Article(*c, **kwargs)`
    A styled article container for blog posts or similar content

- `def ArticleTitle(*c, **kwargs)`
    A title component for use within an Article

- `def ArticleMeta(*c, **kwargs)`
    A metadata component for use within an Article showing things like date, author etc

- `class SectionT(Enum)`
    Section styles from https://franken-ui.dev/docs/section
    Members: default, muted, primary, secondary, xs, sm, lg, xl, remove_vertical


- `def Section(*c, **kwargs)`
    Section with styling and margins

- `def Form(*c, **kwargs)`
    A Form with default spacing between form elements

- `def Fieldset(*c, **kwargs)`
    A Fieldset with default styling

- `def Legend(*c, **kwargs)`
    A Legend with default styling

- `def Input(*c, **kwargs)`
    An Input with default styling

- `def Radio(*c, **kwargs)`
    A Radio with default styling

- `def CheckboxX(*c, **kwargs)`
    A Checkbox with default styling

- `def Range(*c, **kwargs)`
    A Range with default styling

- `def TextArea(*c, **kwargs)`
    A Textarea with default styling

- `def Switch(*c, **kwargs)`
    A Switch with default styling

- `def Upload(*c, **kwargs)`
    A file upload component with default styling

- `def UploadZone(*c, **kwargs)`
    A file drop zone component with default styling

- `def FormLabel(*c, **kwargs)`
    A Label with default styling

- `class LabelT(Enum)`
    Members: primary, secondary, destructive


- `def Label(*c, **kwargs)`
    FrankenUI labels, which look like pills

- `def UkFormSection(title, description, *c)`
    A form section with a title, description and optional button

- `def GenericLabelInput(label, lbl_cls, input_cls, container, cls, id, input_fn, **kwargs)`
    `Div(Label,Input)` component with Uk styling injected appropriately. Generally you should higher level API, such as `LabelInput` which is created for you in this library

- `def LabelInput(label, lbl_cls, input_cls, cls, id, **kwargs)`
    A `FormLabel` and `Input` pair that provides default spacing and links/names them based on id

- `def LabelRadio(label, lbl_cls, input_cls, container, cls, id, **kwargs)`
    A FormLabel and Radio pair that provides default spacing and links/names them based on id

- `def LabelCheckboxX(label, lbl_cls, input_cls, container, cls, id, **kwargs)`
    A FormLabel and CheckboxX pair that provides default spacing and links/names them based on id

- `def Options(*c)`
    Helper function to wrap things into `Option`s for use in `Select`

- `def Select(*option, **kwargs)`
    Creates a select dropdown with uk styling and option for adding a search box

- `def LabelSelect(*option, **kwargs)`
    A FormLabel and Select pair that provides default spacing and links/names them based on id

- `@delegates(GenericLabelInput, but=['input_fn', 'cls']) def LabelRange(label, lbl_cls, input_cls, cls, id, value, min, max, step, label_range, **kwargs)`
    A FormLabel and Range pair that provides default spacing and links/names them based on id

- `class AT(Enum)`
    Link styles from https://franken-ui.dev/docs/link
    Members: muted, text, reset, primary, classic


- `class ListT(Enum)`
    List styles using Tailwind CSS
    Members: disc, circle, square, decimal, hyphen, bullet, divider, striped


- `def ModalContainer(*c, **kwargs)`
    Creates a modal container that components go in

- `def ModalDialog(*c, **kwargs)`
    Creates a modal dialog

- `def ModalHeader(*c, **kwargs)`
    Creates a modal header

- `def ModalBody(*c, **kwargs)`
    Creates a modal body

- `def ModalFooter(*c, **kwargs)`
    Creates a modal footer

- `def ModalTitle(*c, **kwargs)`
    Creates a modal title

- `def ModalCloseButton(*c, **kwargs)`
    Creates a button that closes a modal with js

- `def Modal(*c, **kwargs)`
    Creates a modal with the appropriate classes to put the boilerplate in the appropriate places for you

- `def Placeholder(*c, **kwargs)`
    Creates a placeholder

- `def Progress(*c, **kwargs)`
    Creates a progress bar

- `def UkIcon(icon, height, width, stroke_width, cls, **kwargs)`
    Creates an icon using lucide icons

- `def UkIconLink(icon, height, width, stroke_width, cls, button, **kwargs)`
    Creates an icon link using lucide icons

- `def DiceBearAvatar(seed_name, h, w)`
    Creates an Avatar using https://dicebear.com/

- `def Center(*c, **kwargs)`
    Centers contents both vertically and horizontally by default

- `class FlexT(Enum)`
    Flexbox modifiers using Tailwind CSS
    Members: block, inline, left, center, right, between, around, stretch, top, middle, bottom, row, row_reverse, column, column_reverse, nowrap, wrap, wrap_reverse


- `def Grid(*div, **kwargs)`
    Creates a responsive grid layout with smart defaults based on content

- `def DivFullySpaced(*c, **kwargs)`
    Creates a flex div with it's components having as much space between them as possible

- `def DivCentered(*c, **kwargs)`
    Creates a flex div with it's components centered in it

- `def DivLAligned(*c, **kwargs)`
    Creates a flex div with it's components aligned to the left

- `def DivRAligned(*c, **kwargs)`
    Creates a flex div with it's components aligned to the right

- `def DivVStacked(*c, **kwargs)`
    Creates a flex div with it's components stacked vertically

- `def DivHStacked(*c, **kwargs)`
    Creates a flex div with it's components stacked horizontally

- `class NavT(Enum)`
    Members: default, primary, secondary


- `def NavContainer(*li, **kwargs)`
    Creates a navigation container (useful for creating a sidebar navigation).  A Nav is a list (NavBar is something different)

- `def NavParentLi(*nav_container, **kwargs)`
    Creates a navigation list item with a parent nav for nesting

- `def NavDividerLi(*c, **kwargs)`
    Creates a navigation list item with a divider

- `def NavHeaderLi(*c, **kwargs)`
    Creates a navigation list item with a header

- `def NavSubtitle(*c, **kwargs)`
    Creates a navigation subtitle

- `def NavCloseLi(*c, **kwargs)`
    Creates a navigation list item with a close button

- `class ScrollspyT(Enum)`
    Members: underline, bold


- `def NavBar(*c)`
    Creates a responsive navigation bar with mobile menu support

- `def SliderContainer(*c, **kwargs)`
    Creates a slider container

- `def SliderItems(*c, **kwargs)`
    Creates a slider items container

- `def SliderNav(cls, prev_cls, next_cls, **kwargs)`
    Navigation arrows for Slider component

- `def Slider(*c, **kwargs)`
    Creates a slider with optional navigation arrows

- `def DropDownNavContainer(*li, **kwargs)`
    A Nav that is part of a DropDown

- `def TabContainer(*li, **kwargs)`
    A TabContainer where children will be different tabs

- `class CardT(Enum)`
    Card styles from UIkit
    Members: default, primary, secondary, destructive, hover


- `def CardTitle(*c, **kwargs)`
    Creates a card title

- `def CardHeader(*c, **kwargs)`
    Creates a card header

- `def CardBody(*c, **kwargs)`
    Creates a card body

- `def CardFooter(*c, **kwargs)`
    Creates a card footer

- `def CardContainer(*c, **kwargs)`
    Creates a card container

- `def Card(*c, **kwargs)`
    Creates a Card with a header, body, and footer

- `class TableT(Enum)`
    Members: divider, striped, hover, sm, lg, justify, middle, responsive


- `def Table(*c, **kwargs)`
    Creates a table

- `def TableFromLists(header_data, body_data, footer_data, header_cell_render, body_cell_render, footer_cell_render, cls, sortable, **kwargs)`
    Creates a Table from a list of header data and a list of lists of body data

- `def TableFromDicts(header_data, body_data, footer_data, header_cell_render, body_cell_render, footer_cell_render, cls, sortable, **kwargs)`
    Creates a Table from a list of header data and a list of dicts of body data

- `def apply_classes(html_str, class_map, class_map_mods)`
    Apply classes to html string

- `def render_md(md_content, class_map, class_map_mods)`
    Renders markdown using mistletoe and lxml

- `def get_franken_renderer(img_dir)`
    Create a renderer class with the specified img_dir

- `def ThemePicker(color, radii, shadows, font, mode, cls, custom_themes)`
    Theme picker component with configurable sections

- `def LightboxContainer(*lightboxitem, **kwargs)`
    Lightbox container that will hold `LightboxItems`

- `def LightboxItem(*c, **kwargs)`
    Anchor tag with appropriate structure to go inside a `LightBoxContainer`

- `def ApexChart(**kws)`
    Apex chart component
</doc></api><examples><doc title="Websockets application" desc="Very brief example of using websockets with HTMX and FastHTML">from asyncio import sleep
from fasthtml.common import *

app = FastHTML(exts='ws')
rt = app.route

def mk_inp(): return Input(id='msg')
nid = 'notifications'

@rt('/')
async def get():
    cts = Div(
        Div(id=nid),
        Form(mk_inp(), id='form', ws_send=True),
        hx_ext='ws', ws_connect='/ws')
    return Titled('Websocket Test', cts)

async def on_connect(send): await send(Div('Hello, you have connected', id=nid))
async def on_disconnect( ): print('Disconnected!')

@app.ws('/ws', conn=on_connect, disconn=on_disconnect)
async def ws(msg:str, send):
    await send(Div('Hello ' + msg, id=nid))
    await sleep(2)
    return Div('Goodbye ' + msg, id=nid), mk_inp()

serve()
</doc><doc title="Todo list application" desc="Detailed walk-thru of a complete CRUD app in FastHTML showing idiomatic use of FastHTML and HTMX patterns.">### Walkthrough of an idiomatic fasthtml app ###

# This fasthtml app includes functionality from fastcore, starlette, fastlite, and fasthtml itself.
# Run with: `python adv_app.py`
# Importing from `fasthtml.common` brings the key parts of all of these together. We recommend using a wildcard import since only necessary parts are exported by the module.
from fasthtml.common import *
from hmac import compare_digest

# We recommend using sqlite for most apps, as it is simple, fast, and scalable. `database()` creates the db if it doesn't exist.
db = database('data/utodos.db')
# Create regular classes for your database tables. There are auto-converted to fastcore flexiclasses, which are like dataclasses, but with some extra functionality.
class User: name:str; pwd:str
class Todo: id:int; title:str; done:bool; name:str; details:str; priority:int
# The `create` method creates a table in the database, if it doesn't already exist. The `pk` argument specifies the primary key for the table. If not provided, it defaults to 'id'.
users = db.create(User, pk='name')
# The `transform` argument is used to automatically update the database table, if it exists, to match the class definition. It is a simple and effective migration system for less complex needs. Use the `fastmigrate` package for more sophisticated migrations.
todos = db.create(Todo, transform=True)

# Any Starlette response class can be returned by a FastHTML route handler. In that case, FastHTML won't change it at all.
login_redir = RedirectResponse('/login', status_code=303)

# The `before` function is a *Beforeware* function. These are functions that run before a route handler is called.
def before(req, sess):
    # This sets the `auth` attribute in the request scope, and gets it from the session. The session is a Starlette session, which is a dict-like object which is cryptographically signed, so it can't be tampered with.
    # The `auth` key in the scope is automatically provided to any handler which requests it, and can not be injected by the user using query params, cookies, etc, so it should be secure to use.
    auth = req.scope['auth'] = sess.get('auth', None)
    if not auth: return login_redir
    # `xtra` adds a filter to queries and DDL statements, to ensure that the user can only see/edit their own todos.
    todos.xtra(name=auth)

# Beforeware objects require the function itself, and optionally a list of regexes to skip.
bware = Beforeware(before, skip=[r'/favicon\.ico', r'/static/.*', r'.*\.css', '/login', '/send_login'])

markdown_js = """
import { marked } from "https://cdn.jsdelivr.net/npm/marked/lib/marked.esm.js";
proc_htmx('.markdown', e => e.innerHTML = marked.parse(e.textContent));
"""

# The `FastHTML` class is a subclass of `Starlette`, so you can use any parameters that `Starlette` accepts. In addition, you can add your Beforeware here, and any headers you want included in HTML responses.
def _not_found(req, exc): return Titled('Oh no!', Div('We could not find that page :('))
app = FastHTML(before=bware,
               # These are the same as Starlette exception_handlers, except they also support `FT` results
               exception_handlers={404: _not_found},
               # PicoCSS is a simple CSS system for getting started; for more complex styling try MonsterUI (which wraps uikit and Tailwind)
               hdrs=(picolink, # PicoCSS headers
                     # Look at fasthtml/js.py to see how to add Javascript libraries to FastHTML, like this one.
                     SortableJS('.sortable'),
                     # MarkdownJS is actually provided as part of FastHTML, but we've included the js code here so that you can see how it works.
                     Script(markdown_js, type='module'))
                )
# We add `rt` as a shortcut for `app.route`, which is what we'll use to decorate our route handlers.
rt = app.route

# FastHTML uses Starlette's path syntax, and adds a `static` type which matches standard static file extensions. You can define your own regex path specifiers -- for instance this is how `static` is defined in FastHTML `reg_re_param("static", "ico|gif|jpg|jpeg|webm|css|js|woff|png|svg|mp4|webp|ttf|otf|eot|woff2|txt|xml|html")`
# Provide param to `rt` to use full Starlette route syntax.
@rt("/{fname:path}.{ext:static}", methods=['GET'])
def static_handler(fname:str, ext:str): return FileResponse(f'{fname}.{ext}')

# This function handles GET and POST requests to the `/login` path, because the name of the function automatically becomes the path for the route handler, and GET/POST are available by default. We recommend generally sticking to just these two HTTP verbs.
@rt
def login():
    # This creates a form with two input fields, and a submit button. `Input`, `Form`, etc are `FT` (fasttag) objects. FastHTML composes them from trees and auto-converts them to HTML when needed.
    # You can also use plain HTML strings in handlers and headers, which will be auto-escaped, unless you use `Safe(...string...)`. If you want other custom tags (e.g. `MyTag`), they can be auto-generated by e.g:
    #   `from fasthtml.components import MyTag`.
    # fasttag objects are callable. Calling them adds children and attributes to the tag. Therefore you can use them like this:
    frm = Form(action=send_login, method='post')(
        # Tags with a `name` attr will have `name` auto-set to the same as `id` if not provided
        Input(id='name', placeholder='Name'),
        Input(id='pwd', type='password', placeholder='Password'),
        Button('login'))
    # If a user visits the URL directly, FastHTML auto-generates a full HTML page. However, if the URL is accessed by HTMX, then one HTML partial is created for each element of the tuple.
    # To avoid this auto-generation of a full page, return a `HTML` object, or a Starlette `Response`.
    # `Titled` returns a tuple of a `Title` with the first arg and a `Container` with the rest.
    # A handler can return either a single `FT` object or string, or a tuple of them.
    # In the case of a tuple, the stringified objects are concatenated and returned to the browser. The `Title` tag has a special purpose: it sets the title of the page (this is HTMX's built in behavior for title HTML partials).
    return Titled("Login", frm)

# Handlers are passed whatever information they "request" in the URL, as keyword arguments.
# This handler is called when a POST request is made to the `/login` path. The `login` argument is an instance of the `Login` class, which has been auto-instantiated from the form data.
# There are a number of special parameter names, which will be passed useful information about the request: `session`: the Starlette session; `request`: the Starlette request; `auth`: the value of `scope['auth']`, `htmx`: the HTMX headers, if any; `app`: the FastHTML app object.
# You can also pass any string prefix of `request` or `session`.
@rt
def send_login(name:str, pwd:str, sess):
    if not name or not pwd: return login_redir
    # Indexing into a table queries by primary key, which is `name` here.
    try: u = users[name]
    # If the primary key does not exist, the method raises a `NotFoundError`. Here we use this to just generate a user -- in practice you'd probably to redirect to a signup page.
    # Note that `insert` (and all similar db methods) returns the row object, so we can use it to get the new user.
    except NotFoundError: u = users.insert(name=name, pwd=pwd)
    if not compare_digest(u.pwd.encode("utf-8"), pwd.encode("utf-8")): return login_redir
    # Because the session is signed, we can securely add information to it. It's stored in the browser cookies. If you don't pass a secret signing key to `FastHTML`, it will auto-generate one and store it in a file `./sesskey`.
    sess['auth'] = u.name
    return RedirectResponse('/', status_code=303)

@rt
def logout(sess):
    del sess['auth']
    return login_redir

# Refactoring components in FastHTML is as simple as creating Python functions. The `clr_details` function creates a Div with specific HTMX attributes.
# `hx_swap_oob='innerHTML'` tells HTMX to swap the inner HTML of the target element out-of-band, meaning it will update this element regardless of where the HTMX request originated from. This returned div is empty, so it will clear the details view.
def clr_details(): return Div(hx_swap_oob='innerHTML', id='current-todo')

# Dataclasses, dicts, namedtuples, TypedDicts, and custom classes are automatically instantiated from form data.
# In this case, the `Todo` class is a flexiblass (a subclass of dataclass), so the handler will be passed all the field names of it.
@rt
def update(todo: Todo):
    # The updated todo is returned. By returning the updated todo, we can update the list directly. Because we return a tuple with `clr_details()`, the details view is also cleared.
    # Later on, the `__ft__` method of the `Todo` class will be called to convert it to a fasttag.
    return todos.update(todo), clr_details()

@rt
def edit(id:int):
    # `target_id` specifies which element will be updated with the server's response (it's a shortcut for hx_target=f"#{...}").
    # CheckboxX add an extra hidden field with the same name as the checkbox, so that it can be submitted as part of the form data. This is useful for boolean fields, where you want to know if the field was checked or not.
    res = Form(hx_post=update, target_id=f'todo-{id}', id="edit")(
        Group(Input(id="title"), Button("Save")),
        Hidden(id="id"), CheckboxX(id="done", label='Done'),
        Textarea(id="details", name="details", rows=10))
    # `fill_form` populates the form with existing todo data, and returns the result. Indexing into a table (`todos`) queries by primary key, which is `id` here. It also includes `xtra`, so this will only return the id if it belongs to the current user.
    return fill_form(res, todos[id])

@rt
def rm(id:int):
    # `delete` removes the item with the given primary key.
    todos.delete(id)
    # Returning `clr_details()` ensures the details view is cleared after deletion, leveraging HTMX's out-of-band swap feature.
    # Note that we are not returning *any* FT component that doesn't have an "OOB" swap, so the target element inner HTML is simply deleted.
    return clr_details()

@rt
def show(id:int):
    todo = todos[id]
    # `hx_swap` determines how the update should occur. We use "outerHTML" to replace the entire todo `Li` element.
    # `rm.to(id=todo.id)` is a shortcut for `f'/rm?id={todo.id}'`. All routes have this `to` method.
    btn = Button('delete', hx_post=rm.to(id=todo.id),
                 hx_target=f'#todo-{todo.id}', hx_swap="outerHTML")
    # The "markdown" class is used here because that's the CSS selector we used in the JS earlier. This will trigger the JS to parse the markdown.
    # Because `class` is a reserved keyword in Python, we use `cls` instead, which FastHTML auto-converts.
    return Div(H2(todo.title), Div(todo.details, cls="markdown"), btn)

# `fastcore.patch` adds a method to an existing class.
# The `__ft__` method is a special method that FastHTML uses to convert the object into an `FT` object, so that it can be composed into an FT tree, and later rendered into HTML.
@patch
def __ft__(self:Todo):
    # Some FastHTML tags have an 'X' suffix, which means they're "extended" in some way. For instance, here `AX` is an extended `A` tag, which takes 3 positional arguments: `(text, hx_get, target_id)`.
    # All underscores in FT attrs are replaced with hyphens, so this will create an `hx-get` attr, which HTMX uses to trigger a GET request.
    # Generally, most of your route handlers in practice (as in this demo app) are likely to be HTMX handlers.
    ashow = AX(self.title, show.to(id=self.id), 'current-todo')
    aedit = AX('edit',     edit.to(id=self.id), 'current-todo')
    dt = '✅ ' if self.done else ''
    # FastHTML provides some shortcuts. For instance, `Hidden` is defined as simply: `return Input(type="hidden", value=value, **kwargs)`
    cts = (dt, ashow, ' | ', aedit, Hidden(id="id", value=self.id), Hidden(id="priority", value="0"))
    # Any FT object can take a list of children as positional args, and a dict of attrs as keyword args.
    return Li(*cts, id=f'todo-{self.id}')

@rt
def create(todo:Todo):
    # `hx_swap_oob='true'` tells HTMX to perform an out-of-band swap, updating this element wherever it appears. This is used to clear the input field after adding the new todo.
    new_inp =  Input(id="new-title", name="title", placeholder="New Todo", hx_swap_oob='true')
    # `insert` returns the inserted todo, which is appended to the list start, because we used `hx_swap='afterbegin'` when creating the form.
    return todos.insert(todo), new_inp

# Because the todo list form created earlier included hidden inputs with the todo IDs, they are included in the form data. By using a parameter called (e.g) "id", FastHTML will try to find something suitable in the request with this name. In order, it searches as follows: path; query; cookies; headers; session keys; form data.
# FastHTML will use your parameter's type annotation to try to cast the value to the requested type. In the case of form data, there can be multiple values with the same key. So in this case, the parameter is a list of ints.
@rt
def reorder(id:list[int]):
    # Normally running a query in a loop like this would be really slow. But sqlite is at least as fast as a file system, so this pattern is actually idiomatic and efficient.
    for i,id_ in enumerate(id): todos.update({'priority':i}, id_)
    # HTMX by default replaces the inner HTML of the calling element, which in this case is the todo list form. Therefore, we return the list of todos, now in the correct order, which will be auto-converted to FT for us.
    # In this case, it's not strictly necessary, because sortable.js has already reorder the DOM elements. However, by returning the updated data, we can be assured that there aren't sync issues between the DOM and the server.
    return tuple(todos(order_by='priority'))

# This is the handler for the main todo list application. By including the `auth` parameter, it gets passed the current username, for displaying in the title. `index()` is a special name for the main route handler, and is called when the root path `/` is accessed.
@rt
def index(auth):
    title = f"{auth}'s Todo list"
    top = Grid(H1(title), Div(A('logout', href=logout), style='text-align: right'))
    new_inp = Input(id="new-title", name="title", placeholder="New Todo")
    add = Form(Group(new_inp, Button("Add")),
               hx_post=create, target_id='todo-list', hx_swap="afterbegin")
    # Treating a table as a callable (i.e with `todos(...)` here) queries the table. Because we called `xtra` in our Beforeware, this queries the todos for the current user only.
    # We can include the todo objects directly as children of the `Form`, because the `Todo` class has `__ft__` defined. This is automatically called by FastHTML to convert the `Todo` objects into `FT` objects when needed.
    # The reason we put the todo list inside a form is so that we can use the 'sortable' js library to reorder them. That library calls the js `end` event when dragging is complete, so our trigger here causes our `/reorder` handler to be called.
    frm = Form(*todos(order_by='priority'),
               id='todo-list', cls='sortable', hx_post=reorder, hx_trigger="end")
    # We create an empty 'current-todo' Div at the bottom of our page, as a target for the details and editing views.
    card = Card(P('Drag/drop todos to reorder them'),
                Ul(frm),
                header=add, footer=Div(id='current-todo'))
    # PicoCSS uses `<Main class='container'>` page content; `Container` is a tiny function that generates that.
    return Title(title), Container(top, card)

# You do not need `if __name__ == '__main__':` in FastHTML apps, because `serve()` handles this automatically. By default it reloads the app when the source code changes.
serve()</doc></examples></project>
