title: Typo3: Simplest way to add a custom field to all tt_content in 6.2
body: <p>I am using Typo3 6.2, which has Extension Builder installed in the back-end. I have never built an extension before and am not sure if I need to, but it could be necessary to do what I want. </p>
  
  <p>I have a variety of content types on each page, nested inside of gridelements columns. I want to add a "Background colour" drop-down for all content elements that I can check for in typoscript and assign a class accordingly:</p>
  
  <p><em>Goal HTML, where "green" and "dark" are the classes I want to add:</em></p>
  
  <pre><code> &lt;div class="row"&gt; &lt;-- gridelements
      &lt;div class="column size2"&gt; &lt;-- gridelements
  
          &lt;div class="module green"&gt; &lt;-- content element with green bg
              Some content: could be text, image, news content, etc.
          &lt;/div&gt;
  
          &lt;div class="module dark"&gt; &lt;-- content element with dark bg
              Some content: could be text, image, news content, etc.
          &lt;/div&gt;
  
          &lt;div class="module"&gt; &lt;-- content element with no bg selected
              Some content: could be text, image, news content, etc.
          &lt;/div&gt;
  
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p><em>Here's approximately how I expect to be looking for the "Background colour" field in the typoscript:</em></p>
  
  <pre><code>if{
      value = 1 &lt;--- equal to the value of the drop-down
      equals.field = background_colour &lt;--- the name of my custom field
  }
  //Then add the class to the mark-up
  </code></pre>
  
  <p>I've found a handful of tutorials, none of which really tell me how to do this. 
  This one tells me how to create a whole new content element type, and also uses Kickstarter rather than Extension Builder:
  <a href="http://castironcoding.com/resources/our-blog/sp/view/show/post/reason-6-for-choosing-typo3-custom-content-elements-and-extbase-again-part-23.html?tx_cicblog_list%5Bcontroller%5D=Posts&amp;cHash=13d15edce9ae768be7dd36a140811b82" rel="nofollow">http://castironcoding.com/resources/our-blog/sp/view/show/post/reason-6-for-choosing-typo3-custom-content-elements-and-extbase-again-part-23.html?tx_cicblog_list%5Bcontroller%5D=Posts&amp;cHash=13d15edce9ae768be7dd36a140811b82</a></p>
  
  <p>This one tells me how to extend only News items: 
  <a href="http://docs.typo3.org/typo3cms/extensions/news/latest/Main/Tutorial/ExtendingNews/" rel="nofollow">http://docs.typo3.org/typo3cms/extensions/news/latest/Main/Tutorial/ExtendingNews/</a></p>
  
  <p>Does anyone know of a tutorial in English, or can explain a bit, how it would work to simply add an additional selectable field to all content elements?</p>