A simple TinyMCE 4 plugin to add Click to Tweet HTML to your site.

Click to Tweet TinyMCE 4 Plugin

<script type="text/javascript">
  // Notes: Change @yourname to become your Twitter name.
  tinymce.PluginManager.add('tweet', function(editor, url) {
    // Adds a menu item to the tools menu
    editor.addMenuItem('tweet', {
      text: 'Tweet This',
      context: 'insert',
      onclick: function() {
        editor.windowManager.open({
          title: 'Tweet This',
          body: [
            {type: 'textbox', name: 'message', label: 'Message'}
          ],
          onsubmit: function(e) {
            // Insert content when the window form is submitted
            editor.insertContent('<blockquote> ' + e.data.message + ' @yourname <footer><a href="https://twitter.com/intent/tweet?text=' + encodeURI(e.data.message) + '%20@yourname" target="_blank" rel="nofollow">Tweet This</a></footer></blockquote>');
          }
        });
      }
    });
  });
 
  tinymce.init({
    selector: 'textarea',
    plugins: 'tweet'
  });
</script>