Issue #3238915: Refactor (if feasible) uses of the jQuery ready function to use VanillaJS

core/modules/media_library/src/MediaLibraryState.php

@@ -101,10 +101,10 @@ public static function fromRequest(Request $request) {
     // all validation runs.
     $state = static::create(
       $query->get('media_library_opener_id'),
-      $query->get('media_library_allowed_types', []),
+      $query->all('media_library_allowed_types'),
       $query->get('media_library_selected_type'),
       $query->get('media_library_remaining'),
-      $query->get('media_library_opener_parameters', [])
+      $query->all('media_library_opener_parameters')
     );
 
     // The request parameters need to contain a valid hash to prevent a
@@ -224,7 +224,7 @@ public function getOpenerId() {
    *   The media type IDs.
    */
   public function getAllowedTypeIds() {
-    return $this->get('media_library_allowed_types');
+    return $this->all('media_library_allowed_types');
   }
 
   /**
@@ -268,7 +268,32 @@ public function getAvailableSlots() {
    *   An associative array of all opener-specific parameter values.
    */
   public function getOpenerParameters() {
-    return $this->get('media_library_opener_parameters', []);
+    return $this->all('media_library_opener_parameters');
+  }
+
+  /**
+   * Returns the parameters.
+   *
+   * @param string|null $key
+   *   The name of the parameter to return or null to get them all.
+   *
+   * @return array
+   *   An array of parameters.
+   *
+   * @todo Remove this when Symfony 4 is no longer supported.
+   *   See https://www.drupal.org/node/3162981
+   */
+  public function all(string $key = NULL): array {
+    if ($key === NULL) {
+      return $this->parameters;
+    }
+
+    $value = $this->parameters[$key] ?? [];
+    if (!is_array($value)) {
+      throw new \UnexpectedValueException(sprintf('Unexpected value for parameter "%s": expecting "array", got "%s".', $key, get_debug_type($value)));
+    }
+
+    return $value;
   }
 
   /**