Hướng dẫn create a link/URL with querystrings set/get from parameters

In Drupal 9 I customize the filter in the block in the sidebar menu. When the user clicks on the option in the block, I need to pass his choice to the URL.

SET parameters

$options = ['absolute' => TRUE];
$url = Url::fromRoute('entity.node.canonical', ['node' => 526,'destination'=>'router_back'], $options);
$link = Link::fromTextAndUrl('Here is the link', $url)->toString();

Result link:node/526?destination=router_back

GET parameters

This is a snippet on how to build a custom drupal entity database query that fetches the nodes you want from the database based on custom selection criteria.

 $request_params = \Drupal::request()->query->all();
    // for example my_custom_path?arg1=1&arg2=3&arg3=15 will return an array with arg1 => 1, arg2 => 3 etc
    if (!empty($request_params)) {

      $entity = \Drupal::entityTypeManager()->getStorage('node');
      $query = $entity->getQuery();
      $query->condition('type', 'bundle');
      $query->condition('status', 1);

      foreach ($request_params as $key => $arr) {

        if ($key === 'node_id') {
          $query->condition('field_node_ref',array_keys($arr),'IN');
        }

        if ($key === 'entity_id') {
          $query->condition('field_entity_ref',array_keys($arr),'IN');
        }

        if ($key === 'multiple_value_field') {
          $query->condition('field_multiple_value',array_keys($arr),'IN');
        }

        if ($key === 'field_with_extra_values') {
           $query->condition('field_with_extra_values.starthours', $arr, '<=');
        }

        if ($key === 'field_with_extra_values') {
           $query->condition('field_with_extra_values.endhours', $arr, '>=');
        }

      }
     
      //Get only 4 of them
      $query->range(0,4);

      //sort by DESC custom field value
      $query->sort('field_custom_integer','DESC');

      //most recent
      $query->sort('created','DESC');

      $ids = $query->execute();
   
    }

Get parameter from url in drupal 9

$param = \Drupal::request()->query->all(); To get “uid” from the url, use:
$uid = \Drupal::request()->query->get(‘uid’); To get “num” from the url, use:
$num = \Drupal::request()->query->get(‘num’);

How do I get URL parameters in Drupal 7?

In an ideal scenario, you should use a callback function in a menu and named arguments. But in case you’re in a really particular scenario and need to get arguments like this, you can do it using the arg() function. $category = arg(0);

How do we define routes with URL parameter?

Route params are parameters whose values are set dynamically in a page’s URL. This allows a route to render the same component while passing that component the dynamic portion of the URL, so that it can change its data based on the parameter.

To get $_POST variables in Drupal 8 we need to use \Drupal::request()->request->get method.

Find the route name of the current page in Drupal 8

$current_path = \Drupal::service(‘path. current’)->getPath();
$url_object = \Drupal::service(‘path. validator’)->getUrlIfValid($current_path);
$route_name = $url_object->getRouteName();
$route_parameters = $url_object->getrouteParameters();

To get all params, use:

$param = \Drupal::request()->query->all();

To get "uid" from the url, use:

$uid = \Drupal::request()->query->get('uid');

To get "num" from the url, use:

$num = \Drupal::request()->query->get('num');