title: disable CKEditor indentation plugin
body: <p>I need to disable the indentation of ordered and unordered lists (<code>&lt;ul&gt;</code>, <code>&lt;ol&gt;</code>) in CKEditor (4.2 or 4.3) entirely, because i need to convert (a very limited subset of) HTML into another markup language which does not support indentation.</p>
  
  <p>I've tried several approaches, but didn't have any luck:</p>
  
  <p><strong>Try 1: Remove plugin via configuration</strong></p>
  
  <p><code>config.removePlugins = 'indent,indentlist,indentblock';</code></p>
  
  <p>I guess that is not working because these plugins seem to be required - you can't remove them when building a CKEditor package from the website.</p>
  
  <p>When viewing <code>CKEDITOR.plugins</code> via the FireBug console, those plugins are still there. There doesn't even exist an own plugin folder - seems they are builtin to the core.</p>
  
  <p><strong>Try 2: Override TAB key</strong></p>
  
  <p>I created a new plugin <code>disableTab</code> that does entirely nothing (except <code>return true;</code> on execution).</p>
  
  <p>The plugin is registered as a handler for keystroke of the TAB key:</p>
  
  <pre><code>config.keystrokes = [
       [ 9, 'disableTab' ] // disable TAB key to avoid nesting!
  ];
  </code></pre>
  
  <p>Unfortunately, the plugin doesn't work when pressing tab on the first level of a list (<code>&lt;li&gt;</code> or <code>&lt;ol&gt;</code>). Interestingly, it works when pressing TAB in the second level of a list (<code>ol &gt; li &gt; ol &gt; li</code>), it does not produce more nested lists below the second level. I know for sure my plugin is executed, because i inserted an <code>alert()</code> in my plugin for testing. At least, this is what happens in my Firefox.</p>
  
  <p>But i need to disable indentation entirely, not only above level > 2.</p>
  
  <p><strong>Try 3: Block keystroke via <code>blockedKeystrokes</code> in editor configuration:</strong></p>
  
  <p>Doesn't work, even though it should according to the documentation:</p>
  
  <pre><code>config.blockedKeystrokes = [ 9 ];
  </code></pre>
  
  <p><strong>Try 4: Remove keystroke during runtime</strong></p>
  
  <p>According to the API documentation this code should disable the keystroke, but it doesn't work for some reason:</p>
  
  <pre><code>for (instance in CKEDITOR.instances) {
      var editor = CKEDITOR.instances[instance];
      editor.setKeystroke(9, false);
  }
  </code></pre>
  
  <p><strong>Any idea how to remove the indentation of lists in CKEditor?</strong></p>
  
  <p>I don't understand why none of these approaches work. If you know why, please let me know.</p>
  
  <p><strong>Update:</strong></p>
  
  <p>Interestingly, this code greets me for almost every key event, except pressing the TAB key:</p>
  
  <pre><code>editor.on('key', function(e) { alert ("hi"); return false; });
  </code></pre>
  
  <p>So it seems my setup (LinuxMint 13 [Gnome 2] + Firefox 18 + CKEditor 4.2) does not fire the key event handler for the TAB key. Maybe the indent plugin uses some other event? Blur?</p>
  
  <p><strong>Update 2:</strong></p>
  
  <p>This is a Firefox (maybe linux only) issue. Several approaches work fine with Chrome or Internet Explorer.</p>