Extension hooks¤

from django_components import ComponentExtension, OnComponentClassCreatedContext

class MyExtension(ComponentExtension):
    def on_component_class_created(self, ctx: OnComponentClassCreatedContext) -> None:
        # Add a new attribute to the Component class
        ctx.component_cls.my_attr = "my_value"

from django_components import ComponentExtension, OnComponentClassDeletedContext

class MyExtension(ComponentExtension):
    def on_component_class_deleted(self, ctx: OnComponentClassDeletedContext) -> None:
        # Remove Component class from the extension's cache on deletion
        self.cache.pop(ctx.component_cls, None)

from django_components import ComponentExtension, OnComponentDataContext

class MyExtension(ComponentExtension):
    def on_component_data(self, ctx: OnComponentDataContext) -> None:
        # Add extra template variable to all components when they are rendered
        ctx.template_data["my_template_var"] = "my_value"

from django_components import ComponentExtension, OnComponentInputContext

class MyExtension(ComponentExtension):
    def on_component_input(self, ctx: OnComponentInputContext) -> None:
        # Add extra kwarg to all components when they are rendered
        ctx.kwargs["my_input"] = "my_value"

from django_components import ComponentExtension, OnComponentRegisteredContext

class MyExtension(ComponentExtension):
    def on_component_registered(self, ctx: OnComponentRegisteredContext) -> None:
        print(f"Component {ctx.component_cls} registered to {ctx.registry} as '{ctx.name}'")

from django_components import ComponentExtension, OnComponentRenderedContext

class MyExtension(ComponentExtension):
    def on_component_rendered(self, ctx: OnComponentRenderedContext) -> str | None:
        # Append a comment to the component's rendered output
        return ctx.result + "<!-- MyExtension comment -->"

from django_components import ComponentExtension, OnComponentRenderedContext

class MyExtension(ComponentExtension):
    def on_component_rendered(self, ctx: OnComponentRenderedContext) -> str | None:
        # Raise a new exception
        raise Exception("Error message")

from django_components import ComponentExtension, OnComponentRenderedContext

class MyExtension(ComponentExtension):
    def on_component_rendered(self, ctx: OnComponentRenderedContext) -> str | None:
        if ctx.error is not None:
            # The component raised an exception
            print(f"Error: {ctx.error}")
        else:
            # The component rendered successfully
            print(f"Result: {ctx.result}")

from django_components import ComponentExtension, OnComponentUnregisteredContext

class MyExtension(ComponentExtension):
    def on_component_unregistered(self, ctx: OnComponentUnregisteredContext) -> None:
        print(f"Component {ctx.component_cls} unregistered from {ctx.registry} as '{ctx.name}'")

from django_components import ComponentExtension, OnCssLoadedContext

class MyExtension(ComponentExtension):
    def on_css_loaded(self, ctx: OnCssLoadedContext) -> str | None:
        # Modify the CSS
        return ctx.content.replace("Hello", "Hi")

from django_components import (
    ComponentExtension,
    OnDependenciesContext,
    Script,
    Style,
)

class MyExtension(ComponentExtension):
    def on_dependencies(self, ctx: OnDependenciesContext) -> tuple[list["Script"], list["Style"]]:
        scripts = ctx.scripts
        styles = ctx.styles

        # Modify existing scripts and styles
        for script in scripts:
            if script.kind == "extra":
                script.wrap = False
        for style in styles:
            if style.kind == "extra":
                style.attrs["media"] = "print"

        # Add extra JS and CSS dependencies (inline content)
        scripts.append(
            Script(
                content="console.log('extension-injected script');",
                wrap=False,
            )
        )
        styles.append(
            Style(
                content="body { background-color: red; }",
            )
        )
        # Add extra JS and CSS dependencies (external URL)
        scripts.append(
            Script(
                url="/static/analytics.js",
                content=None,
            )
        )
        styles.append(
            Style(
                url="/static/print.css",
                content=None,
                attrs={"media": "print"},
            )
        )
        return (scripts, styles)

from django_components import ComponentExtension, OnExtensionCreatedContext

class MyExtension(ComponentExtension):
    def on_extension_created(self, ctx: OnExtensionCreatedContext) -> None:
        # Add a new attribute to the extension instance
        ctx.extension.my_attr = "my_value"

from django_components import ComponentExtension, OnCssLoadedContext

class MyExtension(ComponentExtension):
    def on_js_loaded(self, ctx: OnJsLoadedContext) -> str | None:
        # Modify the JS
        return ctx.content.replace("Hello", "Hi")

from django_components import ComponentExtension, OnRegistryCreatedContext

class MyExtension(ComponentExtension):
    def on_registry_created(self, ctx: OnRegistryCreatedContext) -> None:
        # Add a new attribute to the registry
        ctx.registry.my_attr = "my_value"

from django_components import ComponentExtension, OnRegistryDeletedContext

class MyExtension(ComponentExtension):
    def on_registry_deleted(self, ctx: OnRegistryDeletedContext) -> None:
        # Remove registry from the extension's cache on deletion
        self.cache.pop(ctx.registry, None)

from django_components import ComponentExtension, OnSlotRenderedContext

class MyExtension(ComponentExtension):
    def on_slot_rendered(self, ctx: OnSlotRenderedContext) -> str | None:
        # Append a comment to the slot's rendered output
        return ctx.result + "<!-- MyExtension comment -->"

from django_components import ComponentExtension, OnSlotRenderedContext

class MyExtension(ComponentExtension):
    def on_slot_rendered(self, ctx: OnSlotRenderedContext) -> str | None:
        # Access slot metadata
        slot_node = ctx.slot_node
        slot_owner = slot_node.template_component
        print(f"Slot owner: {slot_owner}")

from django_components import ComponentExtension, OnTemplateCompiledContext

class MyExtension(ComponentExtension):
    def on_template_compiled(self, ctx: OnTemplateCompiledContext) -> None:
        print(f"Template origin: {ctx.template.origin.name}")

from django_components import ComponentExtension, OnTemplateLoadedContext

class MyExtension(ComponentExtension):
    def on_template_loaded(self, ctx: OnTemplateLoadedContext) -> str | None:
        # Modify the template
        return ctx.content.replace("Hello", "Hi")