How to get contextual filter in hook_views_query_alter or hook_views_pre_execute?

Question

I want to alter contextual filter before executing the sql query of views. Is there any way to get current contextual filter in hook_views_query_alter or hook_views_pre_execute? Or which is the better hook to alter contextual filter for views?

Answer 1

The contextual filters are in $view->args.

$view->args is an array of arguments (contextual filters).

So you can do things like this:

/**
 * Implements hook_views_pre_execute().
 */
function MODULENAME_views_pre_execute(&$view) {
  // Set the first contextual filter value.
  $view->args[0] = 1;
}

Answer 2

Using hook_views_pre_view() may be more reliable than hook_views_pre_execute(). Based on https://www.drupal.org/node/2438623, hook_views_pre_execute() is too late in the query build processs. In contrast, https://codedrop.com.au/blog/programatically-altering-contextual-filters-views-drupal-7 provides an example of hook_views_pre_view().

For my own situation, the below code works:

/**
 * Implements hook_views_pre_view().
 */
function mymodule_views_pre_view(&$view, &$display_id, &$args) {
  if ($view->name == 'VIEWNAME' && $view->current_display == 'DISPLAYNAME') {
    $url = arg();
    if (isset($url[1])) {
      // YOU MIGHT HAVE TO ADJUST $url[1] TO MATCH YOUR URL ALIAS.
      if ($normal_path = drupal_get_normal_path($url[1])) {
        $path_args = explode('/', $normal_path);
      }
    }
    if (isset($path_args[1])) {
      $view->args[0] = $path_args[1];
    }
  }
}

Answer 3

I think the best option is use hook_views_pre_execute

Below I share a code that alters the contextual filter by a field that comes from a node:

function hooks_views_pre_build(\Drupal\views\ViewExecutable $view) {
  // Get the node entity by the URL parameter
  $node = \Drupal::routeMatch()->getParameter('node');

  if ($view->id() == 'ViewName' && $view->getDisplay()->display['id'] == 'DisplayName') {
    $filterValue = $node->get('field')->first()->get('entity')->getTarget()->getValue();
    $view->args[0] = $filterValue;
  }
}

And that's it!