Behaviour for dashboard pages, both the built-in pillars and custom pages provided by the host application.

A page is a Phoenix.LiveComponent that additionally implements this behaviour: the parent Observer.Web.IndexLive LiveView forwards its mount, params, info and event callbacks to the page currently being displayed.

Building a custom page

use Observer.Web.Page pulls in Phoenix.LiveComponent and provides overridable default implementations for every callback, so a minimal page only needs render/1:

defmodule MyApp.ObserverQueuePage do
  use Observer.Web.Page

  @impl Phoenix.LiveComponent
  def render(assigns) do
    ~H"""
    <div class="min-h-screen bg-white dark:bg-gray-800 p-4">
      Queue length: {@queue_length}
    </div>
    """
  end

  @impl Observer.Web.Page
  def handle_mount(socket) do
    Phoenix.Component.assign(socket, :queue_length, MyApp.Queue.length())
  end
end

Register the page under a route name when mounting the dashboard:

observer_dashboard "/observer", pages: [queue: MyApp.ObserverQueuePage]

The page shows up in the navigation bar as QUEUE and is served at /observer/queue. Within the component, the standard dashboard assigns are available: @access (:all or :read_only), @user, @params, @theme and @page.

Callback flow

• handle_mount/1 - called from the parent LiveView on mount and before page changes.
• handle_params/3 - called on every Phoenix.LiveView.handle_params/3.
• handle_info/2 - called for any message the parent LiveView does not handle itself.
• handle_parent_event/3 - called for any phx- event the parent does not handle itself.