# Getting Started with AshBackpex

This guide walks you through setting up AshBackpex to create an admin interface for your Ash resources.

## Prerequisites

- An existing Phoenix application with Ash Framework configured
- Backpex installed and configured (see [Backpex documentation](https://backpex.live/))
- At least one Ash resource you want to administer

## Installation

Add `ash_backpex` to your dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:ash_backpex, "~> 0.1.9"}
  ]
end
```

Run `mix deps.get` to install the dependency.

AshBackpex 0.1.9 targets Backpex `~> 0.19.6` and declares that dependency
itself. If your application pins Backpex directly, update its constraint to
match.

## Creating Your First Admin LiveResource

### 1. Ensure You Have an Admin Layout

If you followed the [Backpex installation guide](https://hexdocs.pm/backpex), you should already have an admin layout configured. AshBackpex uses the same layout system as Backpex.

If you need to create a new admin layout, Backpex provides the `Backpex.HTML.Layout.app_shell/1` component as a foundation. Here's an example following Backpex conventions:

```elixir
# lib/my_app_web/components/layouts.ex
defmodule MyAppWeb.Layouts do
  use MyAppWeb, :html

  import Backpex.HTML.Layout

  attr :flash, :map, required: true
  attr :fluid?, :boolean, default: false
  attr :current_url, :string, required: true
  slot :inner_block, required: true

  def admin(assigns) do
    ~H"""
    <.app_shell fluid={@fluid?}>
      <:topbar>
        <.topbar_branding />
        <.topbar_dropdown>
          <:label>
            <div class="btn btn-square btn-ghost">
              <Backpex.HTML.CoreComponents.icon name="hero-user" class="size-6" />
            </div>
          </:label>
          <li>
            <.link href={~p"/"} class="flex justify-between hover:bg-base-200">
              <p>Back to App</p>
            </.link>
          </li>
        </.topbar_dropdown>
      </:topbar>
      <:sidebar>
        <.sidebar_item current_url={@current_url} navigate={~p"/admin/posts"}>
          <Backpex.HTML.CoreComponents.icon name="hero-document-text" class="size-5" /> Posts
        </.sidebar_item>
        <%!-- Add more sidebar items for your resources --%>
      </:sidebar>
      <.flash_messages flash={@flash} />
      {render_slot(@inner_block)}
    </.app_shell>
    """
  end
end
```

See the [Backpex layout documentation](https://hexdocs.pm/backpex/Backpex.HTML.Layout.html) for more details on available components and customization options.

### 2. Create a LiveResource

Create a LiveResource module that uses `AshBackpex.LiveResource`:

```elixir
# lib/my_app_web/live/admin/post_live.ex
defmodule MyAppWeb.Admin.PostLive do
  use AshBackpex.LiveResource

  backpex do
    resource MyApp.Blog.Post
    layout {MyAppWeb.Layouts, :admin}

    fields do
      field :title
      field :content do
        module Backpex.Fields.Textarea
      end
      field :published
      field :inserted_at
    end
  end
end
```

### 3. Add Routes

Add routes for your admin LiveResource:

```elixir
# lib/my_app_web/router.ex
scope "/admin", MyAppWeb.Admin do
  pipe_through [:browser]

  live "/posts", PostLive
end
```

### 4. Visit the Admin

Start your Phoenix server and visit `http://localhost:4000/admin/posts` to see your admin interface.

## Adding More Features

### Searchable Fields

Make fields searchable to enable the search box:

```elixir
fields do
  field :title do
    searchable true
  end
  field :content do
    searchable true
    module Backpex.Fields.Textarea
  end
end
```

### Relationships

Display relationships with navigation links:

```elixir
backpex do
  resource MyApp.Blog.Post
  layout {MyAppWeb.Layouts, :admin}
  load [:author]  # Preload the relationship

  fields do
    field :title
    field :author do
      display_field :name
      live_resource MyAppWeb.Admin.UserLive
    end
  end
end
```

### Filters

Add filters to the index view:

```elixir
backpex do
  resource MyApp.Blog.Post
  layout {MyAppWeb.Layouts, :admin}

  fields do
    field :title
    field :published
    field :status
  end

  filters do
    filter :published do
      module Backpex.Filters.Boolean
    end
    filter :status do
      module Backpex.Filters.Select
    end
  end
end
```

### Custom Sort Order

Set the default sort order:

```elixir
backpex do
  resource MyApp.Blog.Post
  layout {MyAppWeb.Layouts, :admin}
  init_order %{by: :inserted_at, direction: :desc}

  fields do
    # ...
  end
end
```

### Panels for Form Organization

Organize form fields into panels:

```elixir
backpex do
  resource MyApp.Blog.Post
  layout {MyAppWeb.Layouts, :admin}

  panels [
    content: "Content",
    settings: "Settings"
  ]

  fields do
    field :title do
      panel :content
    end
    field :content do
      panel :content
      module Backpex.Fields.Textarea
    end
    field :published do
      panel :settings
    end
    field :status do
      panel :settings
    end
  end
end
```

### Custom Display Names

Customize how resources are labeled:

```elixir
backpex do
  resource MyApp.Blog.Post
  layout {MyAppWeb.Layouts, :admin}
  singular_name "Blog Post"
  plural_name "Blog Posts"

  fields do
    # ...
  end
end
```

### Custom Item Actions

Add or remove item actions:

```elixir
backpex do
  resource MyApp.Blog.Post
  layout {MyAppWeb.Layouts, :admin}

  item_actions do
    strip_default [:delete]  # Remove delete action
    action :archive, MyApp.ItemActions.Archive
  end

  fields do
    # ...
  end
end
```

## Authorization

AshBackpex automatically integrates with Ash authorization policies. The admin will:

- Check `Ash.can?/2` before showing create/edit/delete buttons
- Use `assigns.current_user` as the actor for reads and relationship options
- Persist create and update changesets with their configured actor

Make sure your Ash resources have policies defined and that you're setting
`current_user` in your LiveView assigns. If you provide custom create or update
changeset functions, set that actor on the returned Ash changeset.

Backpex's bulk delete adapter callback does not provide LiveView assigns, so it
cannot currently pass the actor to Ash. Only enable bulk deletion in a
high-trust admin environment.

## Next Steps

- See `AshBackpex.LiveResource.Dsl` for all available DSL options
- Check out the [Backpex documentation](https://backpex.live/) for field types and customization
- Look at the demo application in the `demo/` directory for more examples