djust 0.8.0rc1

@action decorator — React 19 Server Actions equivalent (v0.8.0) — mark a method as a Server Action and _action_state[<method_name>] is auto-populated with {pending, error, result} at handler entry/exit. Templates access the state via context injection: each action's name becomes a context variable. Pairs with the v0.8.0 dj-form-pending attribute (PR #1023): dj-form-pending covers the in-flight client UX (during the network round-trip), @action covers the post-completion server state (after the handler returns). Together: React 19-level form ergonomics with zero per-handler wiring.

from djust import action

class TodoView(LiveView):
    @action
    def create_todo(self, title: str = "", **kwargs):
        if not title:
            raise ValueError("Title is required")
        todo = Todo.objects.create(title=title, user=self.request.user)
        return {"created": todo.id}

{% if create_todo.error %}
    <div class="error">{{ create_todo.error }}</div>
{% elif create_todo.result %}
    <div class="success">Todo {{ create_todo.result.created }} created!</div>
{% endif %}

Implementation:

• New @action decorator in djust.decorators. Wraps the underlying @event_handler (every action is also an event handler — same dispatch path, parameter coercion, permissions, rate limits) and adds the action-state tracking layer.
• On entry: self._action_state[name] = {pending: True, error: None, result: None}.
• On success return: {pending: False, error: None, result: <return_value>}.
• On exception: {pending: False, error: str(exc) or exc.__class__.__name__, result: None} and re-raises.
• LiveView.__init__ initializes _action_state: Dict[str, Dict] = {}.
• ContextMixin.get_context_data() injects each action's state under its name (after the public-attribute walk + JIT serialization, so action names that collide with user-defined attrs win — actions are always the canonical reading of that name).
• Re-running an action resets state (clears previous result on a failure retry, clears previous error on a success retry — the template never sees stale state alongside fresh state).
• Both bare-form @action and called-form @action(description=...) supported.
• New is_action(func) helper for runtime detection.
• Exposed as top-level imports: from djust import action, is_action.

Covered by 18 regression tests in tests/test_action_decorator.py (decorator metadata + event-handler/action distinction, sync success / exception / re-raise / class-name fallback, multiple actions independent state, retry success-after-failure + failure-after-success, both decorator forms, end-to-end context injection via ContextMixin.get_context_data()).

dj-form-pending attribute — React 19 useFormStatus equivalent (v0.8.0) — any element nested inside a <form dj-submit> can declare dj-form-pending="hide|show|disabled" and react automatically when the ancestor form's submit handler is in-flight. No prop drilling, no per-button wiring, no client-side state. The form itself gets a data-djust-form-pending="true" attribute while pending so CSS selectors (form[data-djust-form-pending] .spinner) can hook in without JS. Modes:

• hide — element is hidden via the hidden attribute while pending (idle label that disappears during submit)
• show — element is hidden by default and visible while pending (loading spinner / "Saving…" text)
• disabled — disabled = true while pending; original disabled state restored on resolve. User-disabled elements stay disabled (the helper tracks pre-pending state in data-djust-form-pending-was-disabled).

State is set BEFORE the network round-trip and cleared in a finally block so it always resolves regardless of error. Scope isolation: only [dj-form-pending] descendants of the actually- submitting form react; sibling <form dj-submit> forms on the same page are unaffected. Unknown modes are silently ignored (forward-compatible). Implemented in 09-event-binding.js — _setFormPending(form, pending) helper + 1-line wiring into _handleDjSubmit. Bundle delta: ~80 B gzipped. Covered by 8 JS regression tests in tests/js/dj-form-pending.test.js (data-djust-form-pending toggle, hide/show/disabled modes, user-disabled preservation, plain-form no-op, scope isolation, error-path cleanup, unknown-mode forward-compat).