Implement automatic OAuth setup for Potlatch 2

app/models/client_application.rb

@@ -2,6 +2,7 @@ require 'oauth'
 class ClientApplication < ActiveRecord::Base
   belongs_to :user
   has_many :tokens, :class_name => "OauthToken"
+  has_many :access_tokens
   validates_presence_of :name, :url, :key, :secret
   validates_uniqueness_of :key
   before_validation_on_create :generate_keys
@@ -53,6 +54,20 @@ class ClientApplication < ActiveRecord::Base
     RequestToken.create :client_application => self, :callback_url => self.token_callback_url
   end
 
+  def access_token_for_user(user)
+    unless token = access_tokens.find(:first, :conditions => { :user_id => user.id, :invalidated_at => nil })
+      params = { :user => user }
+
+      permissions.each do |p|
+        params[p] = true
+      end
+
+      token = access_tokens.create(params)
+    end
+    
+    token
+  end
+
   # the permissions that this client would like from the user
   def permissions
     ClientApplication.all_permissions.select { |p| self[p] }

app/models/user.rb

@@ -203,4 +203,10 @@ class User < ActiveRecord::Base
 
     return score.to_i
   end
+
+  ##
+  # return an oauth access token for a specified application
+  def access_token(application_key)
+    return ClientApplication.find_by_key(application_key).access_token_for_user(self)
+  end
 end