Add filter to custom grid created as ui_component

Question

I rephrased my question and got it working (adding filters to a custom grid, that was made with a custom data provider). See question and answer here: Create filterable admin grid from external database table

Answer 1

Ok, I finally found my mistake(?!) - I can get the applied filters in my data-provider php file by using the SessionManagerInterface:

use Magento\Framework\Session\SessionManagerInterface;

class YourClassname extents AbstractDataProvider
{
  protected $session;
  
    public function __construct(
        $name,
        $primaryFieldName,
        $requestFieldName,
        RequestInterface $request,
        UrlInterface $urlBuilder,
        Collection $collectionFactory,
        FilterBuilder $filterBuilder,
        array $meta = [],
        array $data = [],
        Data $helper,
        SessionManagerInterface $session
    ) {
        parent::__construct($name, $primaryFieldName, $requestFieldName, $meta, $data);
        $this->collection = $collectionFactory->load();
        $this->helper = $helper;
        $this->request = $request;
        $this->filterBuilder = $filterBuilder;
        $this->urlBuilder = $urlBuilder;
        $this->prepareUpdateUrl();
        $this->session=$session;
    }
      public function getData()
    {

        $this->session->start();

        $filters=$this->request->getParam('filters');
    }

If anyone faces same problems, feel free to ask.

Some more code from this module and (basically the same) question from me with solution can be found here: Create filterable admin grid from external database table