Content Elements

This covers the documentation on how to create content elements in Contao 4.6 and up. In previous Contao version, Content elements must extend from \Contao\ContentElement and then be registered via the $GLOBAL['TL_CTE'] array.

In Contao, Content Elements are the fundamental content blocks. In its simplest form it is a fragment controller which receives data in form of a content model and returns a response.

These elements are implemented as so called fragment controllers which Contao then renders into the main content, using their defined renderer. See the caching documentation for more information.

Creating a content element is very similar to creating front end modules.

Definition

To create a new content element, the following things must be defined and implemented:

  • Fragment Controller
    The actual implementation of the content element is done via a class that extends from AbstractContentElementController of the Contao core.

  • Service Tag
    To identify the controller as a Contao content element, the service must be tagged with service tag contao.content_element.

    • Type
      The type of a content element is a specific string which is used to identify the element’s template and DCA palette. The type can be set in the service tag. If ommitted the type will be automatically generated by converting the class name of the controller from pascal case to snake case and removing a possible Controller postfix.

    • Category
      All content elements are categorised within the type dropdown of the content element’s palette. A category must be defined in the service tag for each content element.

  • Template
    The template name follows the naming convention mentioned beforehand. It prepends the type of the element with the prefix ce_.

Example

Usually a content element is based on a specific palette in the tl_content DCA configuration.

// contao/dca/tl_content.php
$GLOBALS['TL_DCA']['tl_content']['palettes']['my_content_element'] = 
    '{type_legend},type;{text_legend},text'
;

This very simple palette enables a back end user to fill the (pre-existing) field text via the create and edit view of this content element.

The controller for this content element could look like this:

// src/Controller/ContentElement/MyContentElementController.php
namespace App\Controller\ContentElement;

use Contao\ContentModel;
use Contao\CoreBundle\Controller\ContentElement\AbstractContentElementController;
use Contao\CoreBundle\ServiceAnnotation\ContentElement;
use Contao\Template;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

/**
 * @ContentElement(category="texts")
 */
class MyContentElementController extends AbstractContentElementController
{
    protected function getResponse(Template $template, ContentModel $model, Request $request): Response
    {
        $template->text = $model->text;
        
        return $template->getResponse();
    }
}

In this example the service tag was implemented via annotations.

Using the naming convention for templates mentioned above, the final template name for this content element will be ce_my_content_element:

<!-- contao/templates/ce_my_content_element.html5 -->
<div class="my-content-element">    
    <?= $this->text; ?>
</div>

A template instance of this template will automatically be generated and passed to the controller’s main method. The controller returns the parsed template as a response.

Registration

As mentioned previously a content element is registered by registering a controller as a service and tagging it with the contao.content_element service tag. The service tag supports the following options:

Option Type Description
name string Must be contao.content_element.
type string Optional: The type mentioned in Type can be customized.
category string Defines in which option group this content element will be placed in the content element selector.
template string Optional: Override the generated template name.
renderer string Optional: The renderer can be changed to inline or esi. Defaults to forward. See Caching Fragments for more details.
method string Optional: Which method should be invoked on the controller.

Applying the service tag can either be done via PHP attributes, annotations or via the YAML configuration.

since 4.13

A content element can be registered using the AsContentElement PHP attribute.

// src/Controller/ContentElement/ExampleController.php
namespace App\Controller\ContentElement;

use Contao\CoreBundle\Controller\ContentElement\AbstractContentElementController;
use Contao\CoreBundle\DependencyInjection\Attribute\AsContentElement;
use Contao\ContentModel;
use Contao\Template;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

#[AsContentElement(category:'texts')]
class ExampleController extends AbstractContentElementController
{
    protected function getResponse(Template $template, ContentModel $model, Request $request): Response
    {
        return $template->getResponse();
    }
}

The above example only defines the mandatory category attribute. If you wish you can also define the other options of the service tag:

// src/Controller/ContentElement/ExampleController.php
namespace App\Controller\ContentElement;

use Contao\CoreBundle\Controller\ContentElement\AbstractContentElementController;
use Contao\CoreBundle\DependencyInjection\Attribute\AsContentElement;
use Contao\ContentModel;
use Contao\Template;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

#[AsContentElement('example', category:'texts', template:'ce_example', renderer:'forward', method:'__invoke')]
class ExampleController extends AbstractContentElementController
{
    protected function getResponse(Template $template, ContentModel $model, Request $request): Response
    {
        return $template->getResponse();
    }
}

since 4.8

A content element can be registered using the ContentElement annotation. The annotation can be used on the class of the content element, if the class is invokable (has an __invoke method) or extends from the AbstractContentElementController. Otherwise the annotation can be used on the method that will deliver the response.

// src/Controller/ContentElement/ExampleController.php
namespace App\Controller\ContentElement;

use Contao\CoreBundle\Controller\ContentElement\AbstractContentElementController;
use Contao\CoreBundle\ServiceAnnotation\ContentElement;
use Contao\ContentModel;
use Contao\Template;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

/**
 * @ContentElement(category="texts")
 */
class ExampleController extends AbstractContentElementController
{
    protected function getResponse(Template $template, ContentModel $model, Request $request): Response
    {
        return $template->getResponse();
    }
}

The above example only defines the mandatory category attribute. If you wish you can also define the other options of the service tag:

// src/Controller/ContentElement/ExampleController.php
namespace App\Controller\ContentElement;

use Contao\CoreBundle\Controller\ContentElement\AbstractContentElementController;
use Contao\CoreBundle\ServiceAnnotation\ContentElement;
use Contao\ContentModel;
use Contao\Template;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

/**
 * @ContentElement("example", category="texts", template="ce_example", renderer="forward", method="__invoke")
 */
class ExampleController extends AbstractContentElementController
{
    protected function getResponse(Template $template, ContentModel $model, Request $request): Response
    {
        return $template->getResponse();
    }
}

since 4.8

A content element can be registered using the contao.content_element service tag.

# config/services.yaml
services:
    App\Controller\ContentElement\ExampleController:
        tags:
            -
                name: contao.content_element
                category: texts
// src/Controller/ContentElement/ExampleController.php
namespace App\Controller\ContentElement;

use Contao\CoreBundle\Controller\ContentElement\AbstractContentElementController;
use Contao\ContentModel;
use Contao\Template;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

class ExampleController extends AbstractContentElementController
{
    protected function getResponse(Template $template, ContentModel $model, Request $request): Response
    {
        return $template->getResponse();
    }
}

The above example only defines the mandatory category attribute. If you wish you can also define the other options of the service tag:

# config/services.yaml
services:
    App\Controller\ContentElement\ExampleController:
        tags:
            -
                name: contao.content_element
                category: texts
                template: ce_example
                renderer: forward
                method: __invoke

You can also use class constants within attributes and annotations. This can be helpful to make the module’s type a reusable reference:

/**
 * @ContentElement(ExampleController::TYPE, category="miscellaneous")
 */
class ExampleController extends AbstractContentElementController
{
    public const TYPE = 'my_element';
}
// contao/dca/tl_content.php
use App\Controller\ContentElement\ExampleController;

$GLOBALS['TL_DCA']['tl_content']['palettes'][ExampleController::TYPE] = 
   '{type_legend},type;{text_legend},text'
;
// contao/languages/en/default.php
use App\Controller\ContentElement\ExampleController;

$GLOBALS['TL_LANG']['CTE'][ExampleController::TYPE] = [
    'My Example Element', 
    'A Content Element for testing purposes.',
];

Translations

In order to have a nice label in the back end, we also need to add a translation for our content element - otherwise it will only be named my_content_element. The translation needs to be set as follows:

// contao/languages/en/default.php
$GLOBALS['TL_LANG']['CTE']['my_content_element'] = [
    'My Content Element', 
    'A Content Element for testing purposes.',
];

If you used a custom category for your content element, its label can also be translated there.

PageModel

This feature is available in Contao 4.9.10 and later.

If your fragment extends from AbstractContentElementController (or just AbstractFragmentController) you can use $this->getPageModel() in order to receive the \Contao\PageModel object of the currently rendered page of Contao’s site structure.

// src/Controller/ContentElement/MyContentElementController.php
namespace App\Controller\ContentElement;

use Contao\ContentModel;
use Contao\CoreBundle\Controller\ContentElement\AbstractContentElementController;
use Contao\CoreBundle\ServiceAnnotation\ContentElement;
use Contao\Template;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

/**
 * @ContentElement(category="texts")
 */
class MyContentElementController extends AbstractContentElementController
{
    protected function getResponse(Template $template, ContentModel $model, Request $request): Response
    {
        $page = $this->getPageModel();

        // Get some information about the current page
        $template->rootTitle = $page->rootPageTitle ?: $page->rootTitle;
        
        return $template->getResponse();
    }
}

Wrapper Elements

In Contao there are special content elements called “wrappers” which you insert before and after one or a group of content elements. These wrappers affect the back end view, indicating that all elements contained within the two wrappers are decendants of the parent wrapper. The wrapper content elements typically consist of a startand stop element, though there are also wrappers of type single and separator. The start element typically opens a specific HTML tag, while the stop element will close it again.

In order to define that a content element is a wrapper of a specific type, it needs to be registered in the $GLOBALS['TL_WRAPPERS'] array in your contao/config/config.php. The $GLOBALS['TL_WRAPPERS'] array holds the element types for each type of wrapper. For example:

// contao/config.php
$GLOBALS['TL_WRAPPERS']['start'][] = 'my_start_element';
$GLOBALS['TL_WRAPPERS']['stop'][] = 'my_stop_element';

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