Plugging a RTE


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Issue #78 states that this contents needs an update. It says:

The documentation of "Plugging a RTE" seems to be deprecated since TYPO3 CMS 7.4. RTE registration isn't made via $GLOBALS['TYPO3_CONF_VARS']['BE']['RTE_reg'] anymore. Instead the NodeFactory API is used.

TYPO3 supports any Rich Text Editor for which someone might write a connector to the RTE API. This means that you can freely choose whatever RTE you want to use among those available from the Extension Repository on

TYPO3 comes with a built-in RTE called "rtehtmlarea", but other RTEs are available in the TYPO3 Extension Repository.

You can enable more than one RTE if you like but only one will be active at a time. Since Rich Text Editors often depend on browser versions, operating systems etc. each RTE must have a method in the API class which reports back to the system if the RTE is available in the current environment. The Rich Text Editor available to the backend user will be the first loaded RTE which reports back to TYPO3 that it is available in the environment. If the RTE is not available, the next RTE Extension loaded will be asked.

API for Rich Text Editors

Connecting an RTE in an extension to TYPO3 is easy.

  • Create a class file in your extension that extends the system class, \TYPO3\CMS\Backend\Rte\AbstractRte and override functions from the parent class to the degree needed.

  • In the ext_localconf.php file put an entry in $GLOBALS['TYPO3_CONF_VARS']['BE']['RTE_reg'] which registers the new RTE with the system. For example:

    $GLOBALS['TYPO3_CONF_VARS']['BE']['RTE_reg']['myrte'] = array(
       'objRef' => 'Foo\\MyRte\\Editors\\RteBase');

where the value of objRef is the fully qualified name of the class you declared in the first step.

There are three main methods of interest in the base class for the RTE API (\TYPO3\CMS\Backend\Rte\AbstractRte):

  • isAvailable() This method is asked for the availability of the RTE. This is where you should check for environmental requirements that is needed for your RTE. Basically the method must return TRUE if the RTE is available. If it is not, the RTE can put text entries in the internal array ->errorLog which is used to report back the reason why it was not available.
  • drawRTE(&$pObj, $table, $field, $row, $PA, $specConf, $thisConfig, $RTEtypeVal, $RTErelPath, $thePidValue) This method draws the content for the editing form of the RTE. It is called from the \TYPO3\CMS\Backend\Form\FormEngine class which also passes a reference to itself in $pObj. For details on the arguments in the method call, please see inside \TYPO3\CMS\Backend\Rte\AbstractRte.
  • transformContent($dirRTE, $value, $table, $field, $row, $specConf, $thisConfig, $RTErelPath,$pid) This method is used both from ->drawRTE() and from \TYPO3\CMS\Core\DataHandling\DataHandler to transform the content between the database and RTE. When content is loaded from the database to the RTE (and vice versa) it may need some degree of transformation. For instance references to links and images in the database might have to be relative while the RTE requires absolute references. This is just a simple example of what "transformations" can do for you and why you need them. See the next chapter for more details about transformations.