[BUGFIX] Initialize T3editor properly

If a T3editor is instantiated on-the-fly, it is not initialized properly.
Add a callback to the ``Form/Element/T3editorElement`` class and mark
editor instances as initialized to prevent double initialization.

Change-Id: I8c6b692eb2c132180ed0d122b35515276df5acd9
Resolves: #73425
Releases: master, 7.6
Reviewed-on: https://review.typo3.org/46680


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>

typo3/sysext/t3editor/Classes/Form/Element/T3editorElement.php

@@ -123,6 +123,7 @@ class T3editorElement extends AbstractFormElement
             $this->data['tableName'] . ' > ' . $this->data['fieldName'],
             array('target' => 0)
         );
+        $this->resultArray['additionalJavaScriptPost'][] = 'require(["TYPO3/CMS/T3editor/T3editor"], function(T3editor) {T3editor.findAndInitializeEditors();});';
 
         $this->initJavascriptCode();
         return $this->resultArray;
@@ -158,7 +159,6 @@ class T3editorElement extends AbstractFormElement
     protected function initJavascriptCode()
     {
         $this->resultArray['stylesheetFiles'][] = $this->relExtPath . 'Resources/Public/Css/t3editor.css';
-        $this->resultArray['requireJsModules'][] = 'TYPO3/CMS/T3editor/T3editor';
         if ($this->mode === self::MODE_TYPOSCRIPT) {
             foreach ($this->codeCompletionComponents as $codeCompletionComponent) {
                 $this->resultArray['requireJsModules'][] = 'TYPO3/CMS/T3editor/Plugins/CodeCompletion/' . $codeCompletionComponent;

typo3/sysext/t3editor/Resources/Public/JavaScript/T3editor.js

@@ -45,6 +45,9 @@ define(['jquery',
 	 * @param {Number} index
 	 */
 	T3editor.initializeEditor = function($editor, index) {
+		if ($editor.data('initialized')) {
+			return;
+		}
 		var $textarea = $editor.find('textarea'),
 			options = {
 				labels: $textarea.data('labels'),
@@ -76,6 +79,7 @@ define(['jquery',
 				$textarea.hide();
 			}
 		});
+		$editor.data('initialized', true);
 	};
 
 	/**