facebook app link handling

- allow unregistered users to see the app page
- add link to app on profile page

Change-Id: Ia2ce213370ee8cc80e77bd5d01dc01165006fa38
Reviewed-on: https://gerrit.instructure.com/3595
Tested-by: Hudson <hudson@instructure.com>
Reviewed-by: Zach Wily <zach@instructure.com>

app/controllers/facebook_controller.rb

@@ -123,11 +123,6 @@ class FacebookController < ApplicationController
       @service = UserService.find_by_service_and_service_user_id('facebook', @facebook_user_id)
       @user = @service && @service.user
       session[:facebook_user_id] = @facebook_user_id
-      return true
-    else
-      flash[:error] = "Cannot find matching Facebook user"
-      redirect_to dashboard_url
-      return false
     end
   end
 end

app/models/user_service.rb

@@ -221,6 +221,14 @@ class UserService < ActiveRecord::Base
     end
   end
   
+  def service_access_link
+    if service == 'facebook' && Facebook.config && Facebook.config['canvas_name']
+      "https://apps.facebook.com/#{Facebook.config['canvas_name']}"
+    else
+      service_user_link
+    end
+  end
+  
   def service_user_link
     case service
       when 'google_docs'

app/views/profile/profile.html.erb

@@ -220,8 +220,10 @@ you already use.  Click any of the services in "Other Services" to see what we m
       <% @user.user_services.select{|s| !UserService.configured_service?(s.service) || feature_and_service_enabled?(s.service) }.each do |service| %>
         <li class="service" id="service_<%= service.service %>">
           <a href="<%= profile_user_service_url(service.id) %>" class="delete_service_link no-hover" style="float: right; padding-top: 0.5em; padding-right: 10px;" title="Unregister Service"><%= image_tag "delete_circle.png" %></a>
-          <%= image_tag "#{service.service}.png", :style => "vertical-align: middle; float: left;" %> 
-          <div style="float: left; margin-top: 0.5em; padding-left: 5px;">
+          <a href="<%= service.service_access_link %>">
+            <%= image_tag "#{service.service}.png", :style => "vertical-align: middle; float: left;" %> 
+          </a>
+          <div style="float: left; padding-left: 5px;">
             <%= service.service.titleize rescue "Unknown" %>
             <div style="font-size: 0.6em; line-height: 0.5em;">
               <% if service.has_profile_link? %>
@@ -231,6 +233,11 @@ you already use.  Click any of the services in "Other Services" to see what we m
               <% elsif service.has_readable_user_name? %>
                 <span><%= service.service_user_name %></span>
               <% end %>
+              <% if service.service == 'facebook' && feature_and_service_enabled?(:facebook) && Facebook.config['canvas_name'] %>
+                <div>
+                  <a href="<%= service.service_access_link %>">view the Facebook app</a>
+                </div>
+              <% end %>
             </div>
           </div>
           <div class="clear"></div>