title: How select all unique values from select tag in my situation?
body: <p>I have the following code, which select all links, when messenger type includes ['Skype', 'ICQ', 'Jabber']. If user double input skype, need only one first display link on page. How can I add unique links by messenger type?</p>
  <pre><code>&lt;ul class=&quot;list&quot;&gt;
        &lt;% @freelancer.links.select {|link| ['Skype', 'ICQ', 'Jabber'].include? link.messenger_type.title }.each do |link| %&gt;
          &lt;li class=&quot;list__item data&quot;&gt;
            &lt;span class=&quot;data__label&quot;&gt;&lt;%= link.messenger_type.title %&gt;:&lt;/span&gt;
            &lt;span class=&quot;data__value&quot;&gt;&lt;%= link.url %&gt;&lt;/span&gt;
          &lt;/li&gt;
       &lt;% end %&gt;
      &lt;/ul&gt;
  </code></pre>
  <p>model Link.rb</p>
  <pre><code># == Schema Information
  #
  # Table name: links
  #
  #  id                :integer          not null, primary key
  #  url               :string
  #  freelancer_id     :integer
  #  messenger_type_id :integer
  #
  # Indexes
  #
  #  index_links_on_freelancer_id      (freelancer_id)
  #  index_links_on_messenger_type_id  (messenger_type_id)
  #
  </code></pre>