Upgrading to 0.3

Backpex made some significant changes that impacted AshBackpex, so expect this upgrade to take a bit longer than the ones before it.

Backpex's own upgrade guides are the authority for everything Backpex changed. Work through them first, in order, then come back here. This guide covers only what is different or additional in an AshBackpex application, and does not repeat what Backpex's guides already say.

Install the latest 0.3 release.

Errors You May Experience on Upgrading

• The application may stop compiling. Defining can?/3, fields/0, filters/0, item_actions/1, or layout/1 in a LiveResource is now a compile error. Previously, these functions were ignored in favor of AshBackpex DSL declarations, and Ash policies in the case of can?/3.
• Pages that compile may still raise. From 0.1, the admin layout has to change before any page renders (see Backpex's v0.20 guide). From either version, a LiveResource routed with except: [:new] raises on an empty index page until you set create_action false.
• Resource changes run for every row of an index page. A change that reads an unloaded attribute can crash the page.

Update the dependencies

def deps do
  [
    {:ash_backpex, "~> 0.3.3"}
  ]
end

AshBackpex declares its own dependency on Backpex ~> 0.21.0. If your application also lists :backpex, change that constraint to match.

mix deps.update ash_backpex backpex

From 0.1 to 0.2

AshBackpex 0.2 requires Backpex 0.20, which replaced its cookie-based UI state with a preference system and gave the app shell a collapsible sidebar. Upgrading to v0.20 walks through the router, app.js, root and admin layouts, sidebar sections, persistence, and default ordering. The getting-started guide shows the finished result in an AshBackpex application. In addition:

Run your authentication hook first

live_session :backpex_admin,
  on_mount: [{MyAppWeb.LiveUserAuth, :require_admin}, Backpex.InitAssigns] do
  live_resources "/posts", PostLive
end

AshBackpex uses assigns.current_user as the Ash actor, so the hook that assigns it has to run before any LiveResource mounts. Backpex.InitAssigns now reads the user's stored preferences using whatever that hook assigned, so it has to come second.

Admin pages that are not resources

A LiveResource passes every layout assign for you. A LiveView of your own that renders the admin layout, such as a dashboard, has to pass the ones Backpex 0.20 added: socket, sidebar_open, sidebar_section_states, and preferences_manifest. Route it in the same live_session so Backpex.InitAssigns assigns them. See Admin Pages That Are Not Resources.

persist and init_order go in the backpex block

Backpex's guide shows these as use Backpex.LiveResource options. In AshBackpex they are DSL options:

backpex do
  resource MyApp.Blog.Post
  layout {MyAppWeb.Layouts, :admin}
  persist [:columns, :metrics]
  init_order %{by: :inserted_at, direction: :desc}
end

There is no project-wide default for persist; each LiveResource opts in.

From 0.2 to 0.3

AshBackpex 0.3 requires Backpex 0.21, which enforces can?/3 in Backpex.Resource instead of leaving it to each caller. Upgrading to v0.21 covers the new Backpex.Resource signatures, strict item actions, authorize?: false, re-raising Backpex's errors from rescue clauses, and readonly fields.

LiveResources need no change for central enforcement: the can?/3 that Backpex enforces is the one AshBackpex generates from your Ash policies. An item action that writes through your own Ash actions, with the current user as the actor, also needs no change; Ash checks its policies again when it runs. What follows is specific to AshBackpex.

Callbacks that are now compile errors

AshBackpex generates can?/3, fields/0, filters/0, item_actions/1, and layout/1 from the backpex block, so defining one yourself is now a compile error:

MyAppWeb.PostLive defines can?/3 (lib/my_app_web/live/post_live.ex:13),
but AshBackpex generates can?/3 for every LiveResource.

For actions that should be entirely omitted, set the configured backpex action to false. For example, if the admin does not allow updates:

  backpex do
    ...
    update_action false
  end

Other Backpex callbacks (on_item_updated/2, return_to/5, form_actions/2, index_row_class/4, and so on) can still be defined in the module. See "Defining Backpex Callbacks" in AshBackpex.LiveResource.

The New button on an empty index page

Backpex shows a "New" button on an empty index page whenever can?(assigns, :new, nil) is true. It does not look at the routes. A LiveResource routed without :new therefore raises as soon as its table is empty, which is easy to miss in development and easy to hit in a new environment:

live_resources "/events", EventLive, except: [:new, :edit]

Set create_action false in that LiveResource. Do it for every resource routed with except: [:new], not only the ones that crash today.

Resource changes run for every index row

AshBackpex now calls Ash.can?/3 multiple times for every row on the index page: for :edit, for :delete, and for bulk item actions as well, to decide whether the row can be selected. You may run into errors with:

• a change that reads an attribute with select_by_default? false, unless that attribute is one of the LiveResource's declared fields
• a change that reads a relationship, calculation, or aggregate the record has not loaded

Smaller changes

• Bulk deletion runs the LiveResource's destroy_action instead of always calling :destroy. Check any LiveResource whose configured destroy_action differs from its Ash Resource's primary :destroy action.
• A bulk deletion that fails now shows Backpex's error message. It used to report "0 items have been deleted successfully." On data layers that support transactions the whole selection is deleted in one transaction, so a failure deletes nothing. AshSqlite does not support them, so records deleted before the failure stay deleted.
• Readonly text inputs nested inside InlineCRUD and embedded fields render with readonly instead of disabled, so their values are submitted with the form. Top-level readonly fields are still dropped before they reach the Ash action.