debianize-mobilizon/lib/mobilizon_web/uploaders/category.ex

defmodule MobilizonWeb.Uploaders.Category do
  @moduledoc """
  Handles file uploads for categories
  """
  use Arc.Definition
  use Arc.Ecto.Definition

  # To add a thumbnail version:
  @versions [:original, :thumb]
  @extension_whitelist ~w(.jpg .jpeg .gif .png)

  # Override the bucket on a per definition basis:
  # def bucket do
  #   :custom_bucket_name
  # end

  # Whitelist file extensions:
  def validate({file, _}) do
    file_extension = file.file_name |> Path.extname() |> String.downcase()
    Enum.member?(@extension_whitelist, file_extension)
  end

  # Define a thumbnail transformation:
  def transform(:thumb, _) do
    {:convert, "-strip -thumbnail 250x250^ -gravity center -extent 250x250 -format png", :png}
  end

  # Override the persisted filenames:
  def filename(version, {_file, %{title: title}}) do
    "#{title}_#{version}"
  end

  # TODO : When we're sure creating a category is secured and made possible only for admins, use category name
  # Override the storage directory:
  def storage_dir(_, _) do
    "uploads/categories/"
  end

  # Provide a default URL if there hasn't been a file uploaded
  # def default_url(version, scope) do
  #   "/images/avatars/default_#{version}.png"
  # end

  # Specify custom headers for s3 objects
  # Available options are [:cache_control, :content_disposition,
  #    :content_encoding, :content_length, :content_type,
  #    :expect, :expires, :storage_class, :website_redirect_location]
  #
  # def s3_object_headers(version, {file, scope}) do
  #   [content_type: MIME.from_path(file.file_name)]
  # end
end