Upload

An opinionated file uploader for Elixir projects.

Upload offers the following features:

• Minimal API
• Sane defaults
• Ecto integration
• Multiple storage adapters

Installation

The package can be installed by adding upload to your list of dependencies in mix.exs:

def deps do
  [
    {:upload, "~> 0.1.0"}
  ]
end

Usage

Upload a file:

{:ok, upload} = Upload.cast_path("/path/to/file.txt")

# Transfer the upload to storage
{:ok, upload} = Upload.transfer(upload)

# Get the URL for the upload
Upload.get_url(upload)

Ecto Integration

Add a column to store a logo:

def change do
  alter table(:companies) do
    add :logo, :string
  end
end

Add a field to your schema:

schema "companies" do
  field :logo, :string
end

Cast the upload in your changeset:

def changeset(company, attrs \\ %{}) do
  company
  |> cast(attrs, [])
  |> Upload.Ecto.cast_upload(:logo, prefix: ["logos"])
end

Upload in the controller:

def create(conn, %{"logo" => logo}) do
  changeset = Company.changeset(%Company{}, %{"logo" => logo})

  case Repo.insert(changeset) do
    {:ok, company} ->
      # Insert succeeded. Now, you can get the URL:
      Upload.get_url(company.logo)

    {:error, changeset} ->
      # You know the drill.
  end
end

Serving static files

In order to serve the files, you’ll need to setup Plug.Static.

If you’re using Phoenix, you can add this line to endpoint.ex:

plug Plug.Static, at: "/", from: :your_app, gzip: false, only: ~w(uploads)

Configuration

For now, there are four adapters:

• Upload.Adapters.Local - Save files to your local filesystem.
• Upload.Adapters.S3 - Save files to Amazon S3.
• Upload.Adapters.Fake - Don’t actually save the files at all.
• Upload.Adapters.Test - Keep uploaded files in state, so that you can assert.

Upload.Adapters.Local

Out of the box, Upload is ready to go with some sane defaults (for development, at least).

Here are the default values:

config :upload, Upload,
  adapter: Upload.Adapters.Local

config :upload, Upload.Adapters.Local,
  storage_path: "priv/static/uploads",
  public_path: "/uploads"

Upload.Adapters.S3

To use the AWS adapter, you’ll to install ExAws.

Then, you’ll need to following configuration:

config :upload, Upload, adapter: Upload.Adapters.S3
config :upload, Upload.Adapters.S3, bucket: "your_bucket_name"

Upload.Adapters.Test

To use this adapter, you’ll need to the following configuration:

config :upload, Upload, adapter: Upload.Adapters.Test

In your tests, you can make assertions:

setup do
  {:ok, _} = start_supervised(Upload.Adapters.Test)
  :ok
end

test "files are uploaded" do
  assert {:ok, upload} = Upload.cast_path("/path/to/file.txt")
  assert {:ok, upload} = Upload.transfer(upload)
  assert Map.size(Upload.Adapters.Test.get_uploads()) == 1
end

Upload.Adapters.Fake

This adapter does pretty much nothing. It makes absolutely no attempt to persist uploads. This can be useful in unit tests where you want to completely bypass uploading.

To use this adapter, you’ll need the following configuration:

config :upload, Upload, adapter: Upload.Adapters.Fake