Issue #2138665 by dawehner: Allow to specific route parameters to be defined via the views UI.

core/modules/views/lib/Drupal/views/Plugin/views/display/PathPluginBase.php

@@ -145,6 +145,8 @@ protected function getRoute($view_id, $display_id) {
     $argument_ids = array_keys($view_arguments);
     $total_arguments = count($argument_ids);
 
+    $argument_map = array();
+
     // Replace arguments in the views UI (defined via %) with parameters in
     // routes (defined via {}). As a name for the parameter use arg_$key, so
     // it can be pulled in the views controller from the request.
@@ -155,6 +157,13 @@ protected function getRoute($view_id, $display_id) {
         $arg_id = 'arg_' . $argument_ids[$arg_counter++];
         $bits[$pos] = '{' . $arg_id . '}';
       }
+      elseif (strpos($bit, '%') === 0) {
+        // Use the name defined in the path.
+        $parameter_name = substr($bit, 1);
+        $arg_id = 'arg_' . $argument_ids[$arg_counter++];
+        $argument_map[$arg_id] = $parameter_name;
+        $bits[$pos] = '{' . $parameter_name . '}';
+      }
     }
 
     // Add missing arguments not defined in the path, but added as handler.
@@ -190,6 +199,9 @@ protected function getRoute($view_id, $display_id) {
     //   particular important for altering routes.
     $route->setOption('_access_mode', 'ANY');
 
+    // Set the argument map, in order to support named parameters.
+    $route->setDefault('_view_argument_map', $argument_map);
+
     return $route;
   }
 
@@ -445,7 +457,7 @@ public function buildOptionsForm(&$form, &$form_state) {
         $form['path'] = array(
           '#type' => 'textfield',
           '#title' => t('Path'),
-          '#description' => t('This view will be displayed by visiting this path on your site. You may use "%" in your URL to represent values that will be used for contextual filters: For example, "node/%/feed".'),
+          '#description' => t('This view will be displayed by visiting this path on your site. You may use "%" in your URL to represent values that will be used for contextual filters: For example, "node/%/feed". If needed you can even specify named route parameters like taxonomy/term/%taxonomy_term'),
           '#default_value' => $this->getOption('path'),
           '#field_prefix' => '<span dir="ltr">' . url(NULL, array('absolute' => TRUE)),
           '#field_suffix' => '</span>&lrm;',

core/modules/views/tests/Drupal/views/Tests/Plugin/display/PathPluginBaseTest.php

@@ -179,6 +179,42 @@ public function testAlterRoute() {
     $this->assertSame($collection->get('test_route_2'), $route_2);
   }
 
+  /**
+   * Tests the collectRoutes method with a path containing named parameters.
+   *
+   * @see \Drupal\views\Plugin\views\display\PathPluginBase::collectRoutes()
+   */
+  public function testCollectRoutesWithNamedParameters() {
+    /** @var \Drupal\views\ViewExecutable|\PHPUnit_Framework_MockObject_MockObject $view */
+    list($view) = $this->setupViewExecutableAccessPlugin();
+
+    $view->expects($this->once())
+      ->method('initHandlers');
+    $view->argument = array();
+    $view->argument['nid'] = $this->getMockBuilder('Drupal\views\Plugin\views\argument\ArgumentPluginBase')
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $display = array();
+    $display['display_plugin'] = 'page';
+    $display['id'] = 'page_1';
+    $display['display_options'] = array(
+      'path' => 'test_route/%node/example',
+    );
+    $this->pathPlugin->initDisplay($view, $display);
+
+    $collection = new RouteCollection();
+    $result = $this->pathPlugin->collectRoutes($collection);
+    $this->assertEquals(array('test_id.page_1' => 'view.test_id.page_1'), $result);
+
+    $route = $collection->get('view.test_id.page_1');
+    $this->assertTrue($route instanceof Route);
+    $this->assertEquals('/test_route/{node}/example', $route->getPath());
+    $this->assertEquals('test_id', $route->getDefault('view_id'));
+    $this->assertEquals('page_1', $route->getDefault('display_id'));
+    $this->assertEquals(array('arg_nid' => 'node'), $route->getDefault('_view_argument_map'));
+  }
+
   /**
    * Tests alter routes with parameters in the overriding route.
    */