function PluginTypeExampleController::description

Displays a page with an overview of our plugin type and plugins.

Lists all the Sandwich plugin definitions by using methods on the \Drupal\plugin_type_example\SandwichPluginManager class. Lists out the description for each plugin found by invoking methods defined on the plugins themselves. You can find the plugins we have defined in the \Drupal\plugin_type_example\Plugin\Sandwich namespace.

Return value

array Render API array with content for the page at /examples/plugin_type_example.

File

plugin_type_example/src/Controller/PluginTypeExampleController.php, line 47

Class

PluginTypeExampleController

Controller for our example pages.

Namespace

Code

public function description() {
    $build = [];
    $build['intro'] = [
        '#markup' => $this->t("This page lists the sandwich plugins we've created. The sandwich plugin type is defined in Drupal\\plugin_type_example\\SandwichPluginManager. The various plugins are defined in the Drupal\\plugin_type_example\\Plugin\\Sandwich namespace."),
    ];
    // Get the list of all the sandwich plugins defined on the system from the
    // plugin manager. Note that at this point, what we have is *definitions* of
    // plugins, not the plugins themselves.
    $sandwich_plugin_definitions = $this->sandwichManager
        ->getDefinitions();
    // Let's output a list of the plugin definitions we now have.
    $items = [];
    foreach ($sandwich_plugin_definitions as $sandwich_plugin_definition) {
        // Here we use various properties from the plugin definition. These values
        // are defined in the annotation at the top of the plugin class: see
        // \Drupal\plugin_type_example\Plugin\Sandwich\ExampleHamSandwich.
        $items[] = $this->t("@id (calories: @calories, description: @description )", [
            '@id' => $sandwich_plugin_definition['id'],
            '@calories' => $sandwich_plugin_definition['calories'],
            '@description' => $sandwich_plugin_definition['description'],
        ]);
    }
    // Add our list to the render array.
    $build['plugin_definitions'] = [
        '#theme' => 'item_list',
        '#title' => 'Sandwich plugin definitions',
        '#items' => $items,
    ];
    // If we want just a single plugin definition, we can use getDefinition().
    // This requires us to know the ID of the plugin we want. This is set in the
    // annotation on the plugin class: see
    // \Drupal\plugin_type_example\Plugin\Sandwich\ExampleHamSandwich.
    $ham_sandwich_plugin_definition = $this->sandwichManager
        ->getDefinition('meatball_sandwich');
    // To get an instance of a plugin, we call createInstance() on the plugin
    // manager, passing the ID of the plugin we want to load. Let's output a
    // list of the plugins by loading an instance of each plugin definition and
    // collecting the description from each.
    $items = [];
    // The array of plugin definitions is keyed by plugin id, so we can just use
    // that to load our plugin instances.
    foreach ($sandwich_plugin_definitions as $plugin_id => $sandwich_plugin_definition) {
        // We now have a plugin instance. From here on it can be treated just as
        // any other object; have its properties examined, methods called, etc.
        $plugin = $this->sandwichManager
            ->createInstance($plugin_id, [
            'of' => 'configuration values',
        ]);
        $items[] = $plugin->description();
    }
    $build['plugins'] = [
        '#theme' => 'item_list',
        '#title' => 'Sandwich plugins',
        '#items' => $items,
    ];
    return $build;
}