TYPO3 extbase: Simple readable GET parameters - typo3

Question

GET and POST parameters in custom extbase controllers need to be prefixed with the plugin signature to be injected automatically:
<?php
namespace Vendor\Example\Controller;
class SearchController extends \TYPO3\CMS\Extbase\Mvc\Controller\ActionController
{
public function resultsAction($q = null)
{
//...
}
}
Search term $q is only filled automatically if it is passed as ?tx_example_search[q]=foo.
Is there a way declare that the readable version ?q=foo is also fine, and that this should be injected by extbase as well?
(I know that this breaks when multiple plugins on the same page use that parameter, but that's no problem here.)
(The parameter mapping seems already done when ActionController::processRequest() is called, so it must be done earlier.)

Answer 1

You could use the Extbase Plugin enhancer within the routing configuration.
See here: TYPO3 Advanced routing configuration Docs
TYPO3 would then transform the EXTbase URLs into an readable version.
Example:
without the routeEnhancer: yourdomain.com/?tx_example_search[q]=foo
with the routeEnhancer: yourdomain.com/foo
Tipp: You have to define all GET Params otherwise TYPO3 will show the cHash Param.

Answer 2

You can use the method \TYPO3\CMS\Core\Utility\GeneralUtility::_GP($var) in order to retrieve parameters from global variables GET/POST.
Or also \TYPO3\CMS\Core\Utility\GeneralUtility::_GET($var) or \TYPO3\CMS\Core\Utility\GeneralUtility::_POST($var).
Take care of security, those parameters are not sanitized !
If you really want to add the parameter to the action, you have to create an initializeAction() and set the parameter, something like this I guess :
public function initializeResultsAction() {
$myVar = \TYPO3\CMS\Core\Utility\GeneralUtility::_GP('q');
$this->request->setArgument('q', $myVar);
}