Merge remote-tracking branch 'pr/237' into develop

Twitter Feature on Main-View from @loadtocode

Twitter feature within home/index of LEAP web app as feed of tweets of one user's twitter account

How to use it: set up an Application-only authentication by twitter (https://dev.twitter.com/oauth/application-only) and then create a config/secrets.yml including:
```
development:
  twitter:
    enabled: false # set to true for usage
    twitter_handle: XXXXX #put your twitter handle here
    bearer_token: XXXXX #put your bearer token here
test:
  twitter:
    enabled: false # set to true for usage
    twitter_handle: XXXXX #put your twitter handle here
    bearer_token: XXXXX #put your bearer token here
```

things in the PR:

- [x] gemfile:twitter
- [x] twitter helper (caching (to avoid reaching twitter rate limits)
- [x] index twitter view
- [x] twitter css (twitter design as discussed in call: Profil-Header: Picture, Link to twitter + twitter_handle; removed picture and twitter_handle from individual tweet, heading aligns at the top, only the last 3 tweets are shown)
- [x] script to generate bearer token
- [x] script to invalidate generated bearer token
- [x] documentation (Readme + Doc)

1 files changed, 46 insertions, 0 deletions

diff --git a/app/helpers/twitter_helper.rb b/app/helpers/twitter_helper.rb
new file mode 100644
index 0000000..f824a03
--- /dev/null
+++ b/app/helpers/twitter_helper.rb
@@ -0,0 +1,46 @@
+module TwitterHelper
+  def twitter_enabled
+    if Rails.application.secrets.twitter
+      Rails.application.secrets.twitter['enabled'] == true
+    end
+  end
+
+  def twitter_client
+    Twitter::REST::Client.new do |config|
+      config.bearer_token = Rails.application.secrets.twitter['bearer_token']
+    end
+  end
+
+  def twitter_handle
+    Rails.application.secrets.twitter['twitter_handle']
+  end
+
+  def twitter_user_info
+      $twitter_user_info ||= []
+  end
+
+  def update_twitter_info
+    twitter_user_info[0] = Time.now
+    twitter_user_info[1] = twitter_client.user(twitter_handle).name
+    twitter_user_info[2] = twitter_client.user_timeline(twitter_handle).select{ |tweet| tweet.text.start_with?('RT','@')==false}.take(3)
+  end
+
+  def cached_info
+    if twitter_user_info[0] == nil
+      update_twitter_info
+    else
+      if Time.now > twitter_user_info[0] + 15.minutes
+        update_twitter_info
+      end
+    end
+    twitter_user_info
+  end
+
+  def twitter_name
+    cached_info[1]
+  end
+
+  def tweets
+    cached_info[2]
+  end
+end