.. index:: single: Templating Helpers; Slots Helper Slots Helper ============ More often than not, templates in a project share common elements, like the well-known header and footer. Using this helper, the static HTML code can be placed in a layout file along with "slots", which represent the dynamic parts that will change on a page-by-page basis. These slots are then filled in by different children template. In other words, the layout file decorates the child template. Displaying Slots ---------------- The slots are accessible by using the slots helper (``$view['slots']``). Use :method:`Symfony\\Component\\Templating\\Helper\\SlotsHelper::output` to display the content of the slot on that place: .. code-block:: html+php <?php $view['slots']->output('title', 'Default title') ?> output('_content') ?> The first argument of the method is the name of the slot. The method has an optional second argument, which is the default value to use if the slot is not available. The ``_content`` slot is a special slot set by the ``PhpEngine``. It contains the content of the sub-template. .. caution:: If you're using the standalone component, make sure you registered the :class:`Symfony\\Component\\Templating\\Helper\\SlotsHelper`:: use Symfony\Component\Templating\Helper\SlotsHelper; // ... $templateEngine->set(new SlotsHelper()); Extending Templates ------------------- The :method:`Symfony\\Component\\Templating\\PhpEngine::extend` method is called in the sub-template to set its parent template. Then :method:`$view['slots']->set() ` can be used to set the content of a slot. All content which is not explicitly set in a slot is in the ``_content`` slot. .. code-block:: html+php extend('layout.php') ?> set('title', $page->title) ?>

title ?>

body ?>

.. note:: Multiple levels of inheritance is possible: a layout can extend another layout. For large slots, there is also an extended syntax: .. code-block:: html+php start('title') ?> Some large amount of HTML stop() ?>