OAuth2 v0.1.0 → Overview → OAuth2 → Strategy

OAuth2.Strategy behaviour

The OAuth2 strategy specification.

This module defines the required callbacks for all strategies.

Examples

Here’s an example strategy for authenticating with GitHub.

defmodule GitHub do
  use OAuth2.Strategy

  # Public API

  def new do
    OAuth2.new([
      strategy: __MODULE__,
      client_id: "abc123",
      client_secret: "abcdefg",
      redirect_uri: "http://myapp.com/auth/callback",
      site: "https://api.github.com",
      authorize_url: "https://github.com/login/oauth/authorize",
      token_url: "https://github.com/login/oauth/access_token"
    ])
  end

  def authorize_url!(params \\ []) do
    new()
    |> put_param(:scope, "user,public_repo")
    |> OAuth2.Client.authorize_url!(params)
  end

  def get_token!(params \\ [], headers \\ []) do
    OAuth2.Client.get_token!(new(), params, headers)
  end

  # Strategy Callbacks

  def authorize_url(client, params) do
    OAuth2.Strategy.AuthCode.authorize_url(client, params)
  end

  def get_token(client, params, headers) do
    client
    |> put_header("Accept", "application/json")
    |> OAuth2.Strategy.AuthCode.get_token(params, headers)
  end
end

Usage

Generate the authorize URL and redirect the client for authorization.

GitHub.authorize_url!

Capture the code in your callback route on your server and use it to obtain an access token.

token = GitHub.get_token!(code: code)

Use the access token to access desired resources.

user = OAuth2.AccessToken.get!(token, "/user")
Source

Callbacks

authorize_url/2
(callback) # ↑

Specs:

Builds the URL to the authorization endpoint.

Example

def authorize_url(client, params) do
  client
  |> put_param(:response_type, "code")
  |> put_param(:client_id, client.client_id)
  |> put_param(:redirect_uri, client.redirect_uri)
  |> merge_params(params)
end
Source
get_token/3
(callback) # ↑

Specs:

Builds the URL to token endpoint.

Example

def get_token(client, params, headers) do
  client
  |> put_param(:code, params[:code])
  |> put_param(:grant_type, "authorization_code")
  |> put_param(:client_id, client.client_id)
  |> put_param(:client_secret, client.client_secret)
  |> put_param(:redirect_uri, client.redirect_uri)
  |> merge_params(params)
  |> put_headers(headers)
end
Source