Method _render_component

src/py/reactpy/reactpy/core/layout.py:178–229

(
        self,
        exit_stack: AsyncExitStack,
        old_state: _ModelState | None,
        new_state: _ModelState,
        component: ComponentType,
    )

        }

    async def _render_component(
        self,
        exit_stack: AsyncExitStack,
        old_state: _ModelState | None,
        new_state: _ModelState,
        component: ComponentType,
    ) -> None:
        life_cycle_state = new_state.life_cycle_state
        life_cycle_hook = life_cycle_state.hook

        self._model_states_by_life_cycle_state_id[life_cycle_state.id] = new_state

        await life_cycle_hook.affect_component_will_render(component)
        exit_stack.push_async_callback(life_cycle_hook.affect_layout_did_render)
        try:
            raw_model = component.render()
            # wrap the model in a fragment (i.e. tagName="") to ensure components have
            # a separate node in the model state tree. This could be removed if this
            # components are given a node in the tree some other way
            wrapper_model: VdomDict = {"tagName": "", "children": [raw_model]}
            await self._render_model(exit_stack, old_state, new_state, wrapper_model)
        except Exception as error:
            logger.exception(f"Failed to render {component}")
            new_state.model.current = {
                "tagName": "",
                "error": (
                    f"{type(error).__name__}: {error}"
                    if REACTPY_DEBUG_MODE.current
                    else ""
                ),
            }
        finally:
            await life_cycle_hook.affect_component_did_render()

        try:
            parent = new_state.parent
        except AttributeError:
            pass  # only happens for root component
        else:
            key, index = new_state.key, new_state.index
            parent.children_by_key[key] = new_state
            # need to add this model to parent's children without mutating parent model
            old_parent_model = parent.model.current
            old_parent_children = old_parent_model["children"]
            parent.model.current = {
                **old_parent_model,
                "children": [
                    *old_parent_children[:index],
                    new_state.model.current,
                    *old_parent_children[index + 1 :],
                ],
            }

    async def _render_model(
        self,