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https://github.com/jungsoft/uploadex

Elixir library for handling uploads with Ecto, Phoenix and Absinthe
https://github.com/jungsoft/uploadex

elixir storage upload

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Elixir library for handling uploads with Ecto, Phoenix and Absinthe

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# Uploadex



Uploadex is an Elixir library for handling uploads that integrates well with [Ecto](https://github.com/elixir-ecto/ecto), [Phoenix](https://github.com/phoenixframework/phoenix) and [Absinthe](https://github.com/absinthe-graphql/absinthe).



Documentation can be found at https://hexdocs.pm/uploadex.



## Migrating from v2 to v3



1. In you uploader, change `@behaviour Uploadex.Uploader` to `use Uploadex`

1. Remove all `config :uploadex` from your configuration files

1. Change all direct functions calls from `Uploadex.Resolver`, `Uploadex.Files` and `Uploadex` to your Uploader module



## Installation



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



```elixir

def deps do

  [

    {:uploadex, "~> 3.1.0"},

    # S3 dependencies(required for S3 storage only)

    {:ex_aws, "~> 2.1"},

    {:ex_aws_s3, "~> 2.0.2"},

    {:sweet_xml, "~> 0.6"},

  ]

end

```



## Usage



Follow these steps to use Uploadex:



### 1: Uploader



This library relies heavily on pattern matching for configuration, so the first step is to define your Uploader configuration module:



```elixir

defmodule MyApp.Uploader do

  @moduledoc false



  use Uploadex,

    repo: MyApp.Repo # only necessary if using the functions from Uploadex.Context



  alias MyAppWeb.Endpoint



  @impl true

  def get_fields(%User{}), do: :photo

  def get_fields(%Company{}), do: [:photo, :logo]



  @impl true

  def default_opts(Uploadex.FileStorage), do: [base_path: Path.join(:code.priv_dir(:my_app), "static/"), base_url: Endpoint.url()]

  def default_opts(Uploadex.S3Storage), do: [bucket: "my_bucket", region: "sa-east-1", upload_opts: [acl: :public_read]]



  @impl true

  def storage(%User{id: id}, :photo), do: {Uploadex.FileStorage, directory: "/uploads/users/#{id}"}

  def storage(%Company{id: id}, :photo), do: {Uploadex.S3Storage, directory: "/thumbnails/#{id}"}

  def storage(%Company{}, :logo), do: {Uploadex.S3Storage, directory: "/logos"}



  # Optional:

  @impl true

  def accepted_extensions(%User{}, :photo), do: ~w(.jpg .png)

  def accepted_extensions(_any, _field), do: :any

end

```



This example shows the configuration for the [Uploadex.FileStorage](https://hexdocs.pm/uploadex/Uploadex.FileStorage.html#content) and [Uploadex.S3Storage](https://hexdocs.pm/uploadex/Uploadex.S3Storage.html#content) implementations, but you are free to implement your own [Storage](https://hexdocs.pm/uploadex/Uploadex.Storage.html#content).



*Note: To avoid too much metaprogramming magic, the `use` in this module is very simple and, in fact, optional. If you wish to do so, you can just define the `@behaviour Uploadex.Uploader` instead of the `use` and then call all lower level modules directly, passing your Uploader module as argument. The `use` makes life much easier, though!*



### 2: Ecto Migration



A string field is required in the database to save the file reference.

The example below shows what would be needed to have a field to upload.



```elixir

defmodule MyApp.Repo.Migrations.AddPhotoToUsers do

  use Ecto.Migration



  def change do

    alter table(:users) do

      add :photo, :string

    end

  end

end

```



### 3: Schema



In your schema, use the Ecto Type [Uploadex.Upload](https://hexdocs.pm/uploadex/Uploadex.Upload.html#content):



```elixir

schema "users" do

  field :name, :string

  field :photo, Uploadex.Upload

end



# No special cast is needed, and casting does not have any side effects.

def create_changeset(%User{} = user, attrs) do

  user

  |> cast(attrs, [:name, :photo])

end

```



### 4: Configuration



Depending on which features you are using, you may need extra configurations:



#### S3 Configuration



If you are using the S3 adapter, add this to your configuration file. For more information access the [ex_aws_s3 documentation](https://github.com/ex-aws/ex_aws_s3):



```elixir

config :ex_aws, :s3,

  access_key_id: "key",

  secret_access_key: "secret",

  region: "us-east-1",

  host: "localhost",

  port: "9000",

  scheme: "http://"



config :my_project, :uploads,

  bucket: "uploads",

  region: "us-east-1"

```



### 5: Enjoy!



Now, you can use your defined Uploader to handle your records with their files!



The `use Uploadex` line in your Uploader module will import 3 groups of functions:



#### Context



  The highest level functions are context helpers (see [Context](https://hexdocs.pm/uploadex/Uploadex.Context.html) for more documentation), which will allow you to easily create, update and delete your records with associated files:



  ```elixir

  defmodule MyApp.Accounts do

    alias MyApp.Accounts.User

    alias MyApp.MyUploader



    def create_user(attrs) do

      %User{}

      |> User.create_changeset(attrs)

      |> MyUploader.create_with_file()

    end



    def update_user(%User{} = user, attrs) do

      user

      |> User.update_changeset(attrs)

      |> MyUploader.update_with_file(user)

    end



    def delete_user(%User{} = user) do

      MyUploader.delete_with_file(user)

    end

  end

  ```



#### Resolver



  There are also functions to help you easily fetch the files in Absinthe schemas:



  ```elixir

  object :user do

    field :photo_url, :string, resolve: MyUploader.get_file_url(:photo)

  end



  object :user do

    field :photos, list_of(:string), resolve: MyUploader.get_files_url(:photos)

  end

  ```



  See [Resolver](https://hexdocs.pm/uploadex/Uploadex.Resolver.html#content) for more documentation.



#### Files



If you need more flexibility, you can use the lower-level functions defined in [Files](https://hexdocs.pm/uploadex/Uploadex.Files.html#content), which provide some extra functionalities, such as `get_temporary_file`, useful when the files are not publicly available.



Some examples:



```elixir

{:ok, %User{}} = MyUploader.store_files(user)

{:ok, %User{}} = MyUploader.delete_files(user)

{:ok, %User{}} = MyUploader.delete_previous_files(user, user_after_change)

{:ok, files} = MyUploader.get_files_url(user, :photos)

```



## Testing



For knowing how to test with Uploadex, check the hexdocs of the [Testing](https://hexdocs.pm/uploadex/Uploadex.Testing.html#content) module.



## Motivation



Even though there already exists a library for uploading files that integrates with ecto (https://github.com/stavro/arc_ecto), this library was created because:



* arc_ecto does not support upload of binary files

* Uploadex makes it easier to deal with records that contain files without having to manage those files manually on every operation

* Using uploadex, the changeset operations have no side-effects and no special casting is needed

* Uploadex offers more flexibility by allowing to define different storage configurations for each struct (or even each field in a struct) in the application

* Uploadex does not rely on global configuration, which makes it easier to work in umbrella applications