My Flickr photos with RoR

As I had some troubles finding out how to show some of my own Flickr photos on this site using the Flickr API and Ruby on Rails I thought it would be useful to write it down in a small tutorial.

STEP 1: Finding a library: rFlickr

Flickr lists 3 possible Ruby frameworks for their API. After trying flickr.rb (no longer available) and not being able to login I decided to switch to rFlickr as it seems the most popular one.

Start with installing the rFlickr library. You may need to uninstall a previous library if you installed another one earlier.

  gem install rflickr
  

STEP 2: Get a Flickr API key

Flickr doesn’t use the username/password combination as most other API's do. An application can ask for permissions which the user has to grant. A token is returned when this is done allowing the application to connect the next time so we'll only have to do this once. Apply for a key at the Flickr website and remember the key and the shared secret. I use a “Web Application” key as I want to use it for my blog.

STEP 3: Get a Flickr token

Start your development environment:

  ./script/console
  

Next load the newly installed rFlickr module and ask for a Flickr frob using the API key and shared secret you got earlier.

  >> require 'flickr'
  => []
  >> flickr = Flickr.new('/tmp/flickr.cache', YOUR_KEY, YOUR_SECRET)
  => #<Flickr:0x...
  >> flickr.auth.login_link
  => 'http://flickr.com/services/auth/?api_sig=a07a7...'
  

This will return a URL you need to copy & paste in your browser to allow the application to read, write and delete your photos. If you don’t need all this permissions your can add the “perms” parameter for a less greedy permissions. Use the following if you only need read access to the photos:

  >> flickr.auth.login_link(perms='read')
  

Allow the application to access your photos when you open the URL. You can request the forb we need and make sure to to keep it for now.

  >> flickr.auth.getFrob
  => '7215760...'
  

Now we’ll need a token. The token is more permanent as the frob but we need the forb to get one. Finally cache the token:

  >> flickr.auth.getToken('YOUR_FROB')
  => #<Flickr::Token:0x...
  >> flickr.auth.cache_token
  => 154
  

STEP 4: Give me my photos!

Now it’s time to do something more useful with the token. What about showing the thumbnails of the 6 last added photos? We’ll need your NSID which is the strange number in your Flickr URL that looks like 26227936@N00.

  def flickr
    require 'flickr'
    photos = Array.new
    flickr = Flickr.new('/tmp/flickr.cache', 'YOUR_KEY', 'YOUR_SECRET')
    photo_list = flickr.people.getPublicPhotos('YOUR_NSID','',6)
    photo_list.each do |photo|
      photos.push( {'id' => photo.id, 'source' => photo.sizes[:Square].source} )
    end
    return photos
  end
  

Look, you now have an array with the last 6 posted public photos and their ID.