I can persist tabmanager state

src/app.py

@@ -5,7 +5,8 @@ from fasthtml.components import *
 
 from myfasthtml.controls.Layout import Layout
 from myfasthtml.controls.TabsManager import TabsManager
-from myfasthtml.controls.helpers import Ids
+from myfasthtml.controls.helpers import Ids, mk
+from myfasthtml.core.commands import Command
 from myfasthtml.core.instances import InstancesManager
 from myfasthtml.myfastapp import create_app
 
@@ -30,11 +31,14 @@ def index(session):
   for i in range(1000):
     layout.left_drawer.append(Div(f"Left Drawer Item {i}"))
   
-  tabs_manager = InstancesManager.get(session, Ids.TabsManager, TabsManager)
-  tabs_manager.add_tab("Users", Div("Content 1"))
-  tabs_manager.add_tab("Users", Div("Content 2"))
-  tabs_manager.add_tab("Users", Div("Content 3"))
+  tabs_manager = TabsManager(session, _id="main")
+  btn = mk.button("Add Tab",
+                  command=Command("AddTab",
+                                  "Add a new tab",
+                                  tabs_manager.on_new_tab, "Tabs", Div("Content")).
+                  htmx(target=f"#{tabs_manager.get_id()}"))
   layout.set_main(tabs_manager)
+  layout.set_footer(btn)
   return layout
 
 

src/myfasthtml/controls/BaseCommands.py

@@ -1,4 +1,5 @@
 class BaseCommands:
   def __init__(self, owner):
     self._owner = owner
-    self._id = owner.get_id()
+    self._id = owner.get_id()
+    self._prefix = owner.get_prefix()

src/myfasthtml/controls/TabsManager.py

@@ -1,11 +1,11 @@
 import uuid
-from dataclasses import dataclass
 from typing import Any
 
 from fasthtml.common import Div, Button, Span
 
 from myfasthtml.controls.BaseCommands import BaseCommands
-from myfasthtml.controls.helpers import Ids
+from myfasthtml.controls.helpers import Ids, mk
+from myfasthtml.core.commands import Command
 from myfasthtml.core.dbmanager import DbObject
 from myfasthtml.core.instances import MultipleInstance, BaseInstance
 from myfasthtml.icons.fluent_p3 import dismiss_circle16_regular
@@ -35,18 +35,25 @@ class TabsManagerState(DbObject):
 
 
 class Commands(BaseCommands):
-  pass
+  def show_tab(self, tab_id):
+    return Command(f"{self._prefix}SowTab",
+                   "Activate or show a specific tab",
+                   self._owner.show_tab, tab_id).htmx(target=f"#{self._id}", swap="outerHTML")
 
 
 class TabsManager(MultipleInstance):
-  def __init__(self, session):
-    super().__init__(session, Ids.TabsManager)
+  def __init__(self, session, _id=None):
+    super().__init__(session, Ids.TabsManager, _id=_id)
     self._state = TabsManagerState(self)
-    self._commands = Commands(self)
+    self.commands = Commands(self)
   
   def get_state(self):
     return self._state
   
+  def on_new_tab(self, label: str, component: Any):
+    self.add_tab(label, component)
+    return self
+  
   def add_tab(self, label: str, component: Any, activate: bool = True) -> str:
     """
     Add a new tab or update an existing one with the same component type, ID and label.
@@ -108,6 +115,13 @@ class TabsManager(MultipleInstance):
     
     return tab_id
   
+  def show_tab(self, tab_id):
+    if tab_id not in self._state.tabs:
+      return None
+    
+    self._state.active_tab = tab_id
+    return self
+  
   def _mk_tab_button(self, tab_id: str, tab_data: dict):
     """
     Create a single tab button with its label and close button.
@@ -122,7 +136,7 @@ class TabsManager(MultipleInstance):
     is_active = tab_id == self._state.active_tab
     
     return Button(
-      Span(tab_data.get("label", "Untitled"), cls="mf-tab-label"),
+      mk.mk(Span(tab_data.get("label", "Untitled"), cls="mf-tab-label"), command=self.commands.show_tab(tab_id)),
       Span(dismiss_circle16_regular, cls="mf-tab-close-btn"),
       cls=f"mf-tab-button {'mf-tab-active' if is_active else ''}",
       data_tab_id=tab_id,

src/myfasthtml/core/dbmanager.py

@@ -42,14 +42,7 @@ class DbObject:
     self._name = name or self.__class__.__name__
     self._db_manager = db_manager or InstancesManager.get(self._session, Ids.DbManager, DbManager)
     
-    # init is possible
-    if self._db_manager.exists_entry(self._name):
-      props = self._db_manager.load(self._name)
-      for k, v in props.items():
-        if hasattr(self, k):
-          setattr(self, k, v)
-    else:
-      self._save_self()
+    self._finalize_initialization()
   
   @contextmanager
   def initializing(self):
@@ -58,8 +51,8 @@ class DbObject:
     try:
       yield
     finally:
+      self._finalize_initialization()
       self._initializing = old_state
-      self._save_self()
   
   def __setattr__(self, name: str, value: str):
     if name.startswith("_") or getattr(self, "_initializing", False):
@@ -73,6 +66,13 @@ class DbObject:
     super().__setattr__(name, value)
     self._save_self()
   
+  def _finalize_initialization(self):
+    if self._db_manager.exists_entry(self._name):
+      props = self._db_manager.load(self._name)
+      self.update(props)
+    else:
+      self._save_self()
+  
   def _save_self(self):
     props = {k: getattr(self, k) for k, v in self._get_properties().items() if not k.startswith("_")}
     if props:
@@ -103,11 +103,14 @@ class DbObject:
     
     properties |= kwargs
     
-    with self.initializing():
-      for k, v in properties.items():
-        if hasattr(self, k) and k not in DbObject._forbidden_attrs:  # internal variables cannot be updated
-          setattr(self, k, v)
+    # save the new state
+    old_state = getattr(self, "_initializing", False)
+    self._initializing = True
+    for k, v in properties.items():
+      if hasattr(self, k) and k not in DbObject._forbidden_attrs:  # internal variables cannot be updated
+        setattr(self, k, v)
     self._save_self()
+    self._initializing = old_state
   
   def copy(self):
     as_dict = self._get_properties().copy()

src/myfasthtml/core/instances.py

@@ -17,9 +17,10 @@ class BaseInstance:
   Base class for all instances (manageable by InstancesManager)
   """
   
-  def __init__(self, session: dict, _id: str, auto_register: bool = True):
+  def __init__(self, session: dict, prefix: str, _id: str, auto_register: bool = True):
     self._session = session
     self._id = _id
+    self._prefix = prefix
     if auto_register:
       InstancesManager.register(session, self)
   
@@ -28,6 +29,9 @@ class BaseInstance:
   
   def get_session(self):
     return self._session
+  
+  def get_prefix(self):
+    return self._prefix
 
 
 class SingleInstance(BaseInstance):
@@ -36,8 +40,7 @@ class SingleInstance(BaseInstance):
   """
   
   def __init__(self, session: dict, prefix: str, auto_register: bool = True):
-    super().__init__(session, prefix, auto_register)
-    self._instance = None
+    super().__init__(session, prefix, prefix, auto_register)
 
 
 class UniqueInstance(BaseInstance):
@@ -47,8 +50,8 @@ class UniqueInstance(BaseInstance):
   """
   
   def __init__(self, session: dict, prefix: str, auto_register: bool = True):
-    super().__init__(session, prefix, auto_register)
-    self._instance = None
+    super().__init__(session, prefix, prefix, auto_register)
+    self._prefix = prefix
 
 
 class MultipleInstance(BaseInstance):
@@ -56,9 +59,9 @@ class MultipleInstance(BaseInstance):
   Base class for instances that can have multiple instances at a time.
   """
   
-  def __init__(self, session: dict, prefix: str, auto_register: bool = True):
-    super().__init__(session, f"{prefix}-{str(uuid.uuid4())}", auto_register)
-    self._instance = None
+  def __init__(self, session: dict, prefix: str, auto_register: bool = True, _id=None):
+    super().__init__(session, prefix, f"{prefix}-{_id or str(uuid.uuid4())}", auto_register)
+    self._prefix = prefix
 
 
 class InstancesManager:

src/myfasthtml/test/matcher.py

@@ -90,6 +90,14 @@ class Empty(ChildrenPredicate):
     return len(actual.children) == 0 and len(actual.attrs) == 0
 
 
+class NoChildren(ChildrenPredicate):
+  def __init__(self):
+    super().__init__(None)
+  
+  def validate(self, actual):
+    return len(actual.children) == 0
+
+
 class AttributeForbidden(ChildrenPredicate):
   """
   To validate that an attribute is not present in an element.