# CapsuleEcto

Ecto integration for [Capsule](https://github.com/elixir-capsule/capsule)

This package adds the following two features to support the use of Capsule with Ecto:

1. Custom Type

    Specify your file field with the following type to get serialization of encapsulated uploads to maps: `field :file_data, Capsule.Ecto.Type`

2. Changeset helper

    Cast params to encapsulated data with `Capsule.Ecto.encapsulate`. In the style of Ecto.Multi, it accepts either an anonymous function or a module and function name, both with arity(2). The first argument passed will be a 2 element tuple representing the key/param pair and the second value will be the changeset.
    It is expected to return either a success tuple with the `Encapsulation` struct or the changeset. In the latter case the changeset will simply be passed on down the pipe.

    So, if you want to store the file in some storage, extract some metadata and apply a simple validation then the anonymous function may be all you need:

    ```
    |> %Attachment{}
    |> Ecto.changeset.change()
    |> Capsule.Ecto.encapsulate(%{"file_data" => some_upload}, [:file_data], fn {_field, upload}, changeset ->
        case Capsule.Storages.Disk.put(upload) do
          {:ok, cap} ->
            Capsule.add_metadata(cap, %{yo: :dawg})
            |> return_upload_or_changeset_with_error
          error_tuple ->
            changeset |> add_error("upload just...failed")
        end

    ```

    However, if you want to do more complicated things with the upload before storing it (such as resizing, encrypting, etc) then creating a module is probably the way to go.

    ```
    |> %Attachment{}
    |> Ecto.changeset.change()
    |> Capsule.Ecto.encapsulate(%{"file_data" => some_upload}, [:file_data], MyApp.Attacher, :attach)
    ```