Flickr Login

This gem is a simple Rack endpoint that provides Flickr authentication in your web application. You just mount it on your web application and it does the rest of the work.

This gem is an alternative to omniauth-flickr. They both provide similar results, the main difference is that flickr-login is much more lightweight. If you don't care about that, I would highly suggest that you go with omniauth-flickr, because omniauth is a great standard for authentication.

If you intend to use the user's access token for communication with Flickr's API, you'll want to use one of these 2 gems:

• flickraw
• flickr-objects

Put it into your Gemfile:

gem "flickr-login", require: "flickr/login"

And run bundle install.

You have to be in possession of your API key and shared secret. If you don't have them yet, you can apply for them here. In the setup, just replace API_KEY and SHARED_SECRET with real values.

This is an example of how you can the gem in Rails 3 (in Rails 2 it's probably similar).

# config/application.rb
module YourApp
  class Application < Rails::Application
    # ...
    config.flickr_login = Flickr::Login.new "API_KEY", "SHARED_SECRET"
    # ...
  end
end

# config/routes.rb
YourApp::Application.routes.draw do
  # ...
  flickr = YourApp::Application.config.flickr_login
  flickr_endpoint = flickr.login_handler(return_to: "/any-path")

  mount flickr_endpoint => '/login', as: :login
  # ...
end

In Sinatra this is being put in your config.ru, which probably looks something like this:

# config.ru
require './app'
run Sinatra::Application

Now you mount the Rack endpoint like this

# config.ru
require './app'
require 'flickr/login'

flickr = Flickr::Login.new "API_KEY", "SHARED_SECRET"
flickr_endpoint = flickr.login_handler(return_to: "/any-path")

use Rack::Session::Cookie
run Rack::URLMap.new "/" => Sinatra::Application,
                     "/login" => flickr_endpoint

That's it. Just enable sessions in your app.rb:

# app.rb
enable :sessions

The user will first get redirected to Flickr to approve your application. The user is then redirected back to your app (back to the path specified with :return_to), with session[:flickr_access_token] and session[:flickr_user] filled in.

• session[:flickr_access_token] – an array of access token and access secret
• session[:flickr_user] – a hash of information about the authenticated user

Available options for Flickr::Login are:

• :return_to – where the user is redirected to after authentication (defaults to "/")
• :site – the API endpoint that is used (defaults to http://www.flickr.com/services)

You can also set the permissions you're asking from the user. You do this by passing the perms GET parameter in the URL. For example, going to http://localhost:9393/login?perms=delete would ask the user for "delete" permissions. You can ask the user for "read", "write" or "delete" permissions.

The Flickr::Login::Helpers module adds these methods to your app:

• #flickr_user (Hash) – The information about the user who just authenticated
• #flickr_access_token (Array) – The access token and secret
• #flickr_clear – Erases the session that was filled after authentication, effectively logging out the user

In Rails you can include the module in your controller:

# app/controllers/session_controller.rb
class SessionController < ApplicationController
  include Flickr::Login::Helpers
end

In Sinatra you can just call the helpers method:

helpers Flickr::Login::Helpers

This gem is almost a direct copy of @mislav's twitter-login and facebook-login gems.

MIT