title: Flexform in typo3 7.6.2 not working
body: <p>I have created a extension using extension builder in typo3 7.6.2 version. Now I would like to add flexform to extension 'Products' for detail page PID. But I tried my best to integrate flexform but it did not work.</p>
  
  <p>Here is my code - </p>
  
  <p>In ext_tables.php - </p>
  
  <pre><code>  \TYPO3\CMS\Extbase\Utility\ExtensionUtility::registerPlugin(
          'Wxproducts.' . $_EXTKEY,
          'Wxproducts',
          'Products'
      );
  
  // flexform integration 
  $pluginSignature = str_replace('_','','Wxproducts'.$_EXTKEY) . '_products';
  $TCA['tt_content']['types']['list']['subtypes_addlist'][$pluginSignature] = 'pi_flexform';
  t3lib_extMgm::addPiFlexFormValue($pluginSignature, 'FILE:EXT:' . $_EXTKEY . '/Configuration/FlexForms/flexform_products.xml');
  </code></pre>
  
  <p>In Configuration/FlexForms/flexform_products.php - </p>
  
  <pre><code>&lt;T3DataStructure&gt;
   &lt;sheets&gt;
    &lt;sDEF&gt;
     &lt;ROOT&gt;
       &lt;TCEforms&gt;
        &lt;sheetTitle&gt;Function&lt;/sheetTitle&gt;
       &lt;/TCEforms&gt;
       &lt;type&gt;array&lt;/type&gt;
       &lt;el&gt;
        &lt;switchableControllerActions&gt;
         &lt;TCEforms&gt;
           &lt;label&gt;Select function&lt;/label&gt;
           &lt;config&gt;
            &lt;type&gt;select&lt;/type&gt;
            &lt;items&gt;
  
              &lt;numIndex index="0"&gt;
               &lt;numIndex index="0"&gt;List&lt;/numIndex&gt;
               &lt;numIndex index="1"&gt;Products-&gt;list&lt;/numIndex&gt;
              &lt;/numIndex&gt;
  
              &lt;numIndex index="1"&gt;
               &lt;numIndex index="0"&gt;Detail&lt;/numIndex&gt;
               &lt;numIndex index="1"&gt;Products-&gt;show&lt;/numIndex&gt;
              &lt;/numIndex&gt;
  
             &lt;/items&gt;
           &lt;/config&gt;
         &lt;/TCEforms&gt;
        &lt;/switchableControllerActions&gt;
       &lt;/el&gt;
     &lt;/ROOT&gt;
    &lt;/sDEF&gt;
   &lt;/sheets&gt;
  &lt;/T3DataStructure&gt;
  </code></pre>
  
  <p>Its not working. I am unable to figure out whats the problem. Any idea!</p>
  
  <p>Thanks in Advance!</p>