Basics

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

Explanation

Ensures that LiveView forms (i.e. forms with phx-submit) carry both an id attribute and a phx-change attribute.

Without these two attributes, LiveView cannot rehydrate the form's state across reconnects or live patches: the user's input is silently lost when the form is re-rendered. The id lets LiveView identify the form across renders, and phx-change keeps the server-side form data in sync with the user's keystrokes so it can be replayed.

Forms without phx-submit are not driven by LiveView and are exempt.

Bad

<.form for={@form} phx-submit="save">
  <.input field={@form[:name]} />
</.form>

<form phx-submit="save">
  <input name="name" />
</form>

Good

<.form for={@form} id="profile-form" phx-submit="save" phx-change="validate">
  <.input field={@form[:name]} />
</.form>

The check scans ~H sigils and .heex template files referenced by embed_templates.

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.