The version history of a dashboard list page: a modal that lists one record's versions a page at a time, previews one of them, and restores one. The page keeps the template, its :versions_modal and the one-line event handlers; everything they do is here.

Every function takes the page's socket and returns it, with the assigns the template reads: :versions, :versions_record_id, :versions_record_name, :versions_loading, :versions_page, :versions_per_page, :versions_total, :version_masters and :preview_version_id.

@versions [
  resource: MishkaBlog.Blogger,
  name: :display_name,
  modal: "blogger-versions-modal",
  not_found: gettext_noop("Blogger not found or access denied")
]

def mount(_params, _session, socket) do
  {:ok, VersionsModal.assign_defaults(socket)}
end

def handle_event("restore_version", %{"version-id" => id}, socket),
  do: {:noreply, VersionsModal.restore(socket, @versions, id)}

def handle_info({:row_action, "show_versions", %{"id" => id}}, socket),
  do: {:noreply, VersionsModal.show(socket, @versions, id)}

def handle_async(:load_versions, result, socket),
  do: {:noreply, VersionsModal.loaded(socket, @versions, result)}

The versions are read, and a version is restored, as the signed-in user in :current_user: a master through the master actions and every site, a site's admin through the site's own.

Options

• :resource - Required. The record's resource. It needs the :get_with_versions and :master_get_with_versions reads, a Version resource beside it, and the :restore_version_api and :master_restore_version_api actions.
• :name - Required. The attribute shown as the modal's subtitle.
• :modal - Required. The DOM id of the versions modal.
• :not_found - Required. The flash for a record that cannot be read.
• :load - What else the read loads, as [master: [...], site: [...]].
• :loaded - A (socket, record) function run once the versions are in, to assign more.