Basics

This check has a base priority of normal and works with any version of Elixir.

Explanation

Enforces a consistent top-to-bottom callback order in Phoenix.LiveView modules:

1. mount
2. handle_params
3. handle_event
4. handle_info
5. handle_async
6. render

Reading a LiveView top-to-bottom in this order matches the lifecycle itself: how the view boots, how it reacts to URL changes, how it reacts to user events, how it reacts to messages, then the rendering. When callbacks are interleaved arbitrarily it takes longer to find the bit of behavior you're looking for and harder to spot missing handlers.

Non-callback def/defp (helpers) are ignored — they may appear anywhere in the module. Only the relative order of the LiveView callbacks listed above is checked.

The check only runs against modules that declare use Phoenix.LiveView directly or use SomethingWeb, :live_view. Multiple clauses of the same callback are fine; they share a bucket. The first out-of-order callback is flagged.

Bad

def mount(_, _, socket), do: {:ok, socket}
def render(assigns), do: ~H""
def handle_event("x", _, socket), do: {:noreply, socket}

Good

def mount(_, _, socket), do: {:ok, socket}
def handle_event("x", _, socket), do: {:noreply, socket}
def render(assigns), do: ~H""

Check-Specific Parameters

There are no specific parameters for this check.

General Parameters

Like with all checks, general params can be applied.

Parameters can be configured via the .credo.exs config file.