DEPRECATION WARNING

This documentation is not using the current rendering mechanism and will be deleted by December 31st, 2020. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.

# Signals¶

Signals are currently only used in the search controller. Every action emits a signal which can be used to change its variables assigned to the view.

## Example¶

As an example, the action resultsAction of the Classes/Controller/SearchController is used.

$values = [ 'hasSearched' =>$this->searchService->getHasSearched(),
'additionalFilters' => $this->searchService->getAdditionalFilters(), 'resultSet' =>$searchResultSet,
'pluginNamespace' => $this->typoScriptConfiguration->getSearchPluginNamespace() ];$values = $this->emitActionSignal(__CLASS__, __FUNCTION__, [$values]);


To fulfill that signal, you can create a slot in your custom extension. All what it needs is an entry in your ext_localconf.php file:

/** @var \TYPO3\CMS\Extbase\SignalSlot\Dispatcher $signalSlotDispatcher */$signalSlotDispatcher = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\SignalSlot\Dispatcher::class);
$signalSlotDispatcher->connect( \ApacheSolrForTypo3\Solr\Controller\SearchController::class, 'resultsAction', \YourVendor\yourextkey\Slot\SearchControllerSlot::class, // fully your choice 'resultsActionSlot', // fully your choice  ); An example call look like this: /** * @param array$values
*/
public function resultsActionSlot($values) {$values['foo'] = 'bar'

return [\$values];
}


Notice: The values array needs to be returned as an single element of an array, because a slot method has to return the same number of arguments like it received.