I can bind elements

src/myfasthtml/core/bindings.py

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+import logging
+import uuid
+from typing import Optional
+
+from fasthtml.fastapp import fast_app
+from myutils.observable import make_observable, bind, collect_return_values
+
+from myfasthtml.core.constants import Routes, ROUTE_ROOT
+from myfasthtml.core.utils import get_default_attr
+
+bindings_app, bindings_rt = fast_app()
+logger = logging.getLogger("Bindings")
+
+
+class Binding:
+  def __init__(self, data, attr=None, ft=None, ft_name=None, ft_attr=None):
+    """
+    Creates a new binding object between a data object used as a pivot and an HTML element.
+      The same pivot object must be used for different bindings.
+      This will allow the binding between the HTML elements
+      
+    :param data: object used as a pivot
+    :param attr: attribute of the data object
+    :param ft: HTML element to bind to
+    :param ft_name: name of the HTML element to bind to (send by the form)
+    :param ft_attr: value of the attribute to bind to (send by the form)
+    """
+    self.id = uuid.uuid4()
+    self.htmx_extra = {}
+    self.data = data
+    self.data_attr = attr or get_default_attr(data)
+    self.ft = self._safe_ft(ft)
+    self.ft_name = ft_name
+    self.ft_attr = ft_attr
+    
+    make_observable(self.data)
+    bind(self.data, self.data_attr, self.notify)
+    
+    # register the command
+    BindingsManager.register(self)
+  
+  def bind_ft(self, ft, name, attr=None):
+    """
+    Update the elements to bind to
+    :param ft:
+    :param name:
+    :param attr:
+    :return:
+    """
+    self.ft = self._safe_ft(ft)
+    self.ft_name = name
+    self.ft_attr = attr
+  
+  def get_htmx_params(self):
+    return self.htmx_extra | {
+        "hx-post": f"{ROUTE_ROOT}{Routes.Bindings}",
+        "hx-vals": f'{{"b_id": "{self.id}"}}',
+    }
+  
+  def notify(self, old, new):
+    logger.debug(f"Binding '{self.id}': Changing from '{old}' to '{new}'")
+    if self.ft_attr is None:
+      self.ft.children = (new,)
+    else:
+      self.ft.attrs[self.ft_attr] = new
+    
+    self.ft.attrs["hx-swap-oob"] = "true"
+    return self.ft
+  
+  def update(self, values: dict):
+    logger.debug(f"Binding '{self.id}': Updating with {values=}.")
+    for key, value in values.items():
+      if key == self.ft_name:
+        setattr(self.data, self.data_attr, value)
+        res = collect_return_values(self.data)
+        return res
+    
+    else:
+      logger.debug(f"Nothing to trigger in {values}.")
+      return None
+  
+  @staticmethod
+  def _safe_ft(ft):
+    """
+    Make sure the ft has an id.
+    :param ft:
+    :return:
+    """
+    if ft is None:
+      return None
+    
+    if ft.attrs.get("id", None) is None:
+      ft.attrs["id"] = str(uuid.uuid4())
+    return ft
+  
+  def htmx(self, trigger=None):
+    if trigger:
+      self.htmx_extra["hx-trigger"] = trigger
+    return self
+
+class BindingsManager:
+  bindings = {}
+  
+  @staticmethod
+  def register(binding: Binding):
+    BindingsManager.bindings[str(binding.id)] = binding
+  
+  @staticmethod
+  def get_binding(binding_id: str) -> Optional[Binding]:
+    return BindingsManager.bindings.get(str(binding_id))
+  
+  @staticmethod
+  def reset():
+    return BindingsManager.bindings.clear()