Item Query

It is possible to manipulate the query when fetching resources for index, show and edit view when using Backpex.Adapters.Ecto.

In all queries we define a from query with a named binding to fetch all existing resources on index view or a specific resource on show / edit view. After that, we call the item_query function. By default it returns the incoming query.

The item_query function makes it easy to add custom query expressions.

Configuration

To add a custom query to a resource, you need to provide a function to the item_query option in your adapter_config.

# in your resource configuration file (live resource)
use Backpex.LiveResource,
  # ...other options
  adapter_config: [
    # ...other adapter options
    item_query: &__MODULE__.item_query/3
  ]

  def item_query(query, :index, _assigns) do
    query
    |> where([post], post.published)
  end

  def item_query(query, _live_action, _assigns) do
    query
  end

The example above will filter all posts by a published boolean on index view. We also made use of the named binding. It's always the name of the provided schema in snake_case. It is recommended to build your item_query on top of the incoming query. Otherwise you will likely get binding errors.

Make sure to always cover all possible cases or add a fallback item_query/3 function that just returns the query.