Helpers¶

Using Helpers¶

You use helpers in CakePHP by making a controller aware of them. Each controller has a $helpers property that lists the helpers to be made available in the view. To enable a helper in your view, add the name of the helper to the controller’s $helpers array.

<?php
class BakeriesController extends AppController {
    var $helpers = array('Form', 'Html', 'Javascript', 'Time');
}
?>

You can also add helpers from within an action, so they will only be available to that action and not the other actions in the controller. This saves processing power for the other actions that do not use the helper as well as help keep the controller better organized.

<?php
class BakeriesController extends AppController {
    function bake {
        $this->helpers[] = 'Time';
    }
    function mix {
        // The Time helper is not loaded here and thus not available
    }
}
?>

If you need to enable a helper for all controllers add the name of the helper to the $helpers array in /app/app_controller.php (or create if not present). Remember to include the default Html and Form helpers.

<?php
class AppController extends Controller {
    var $helpers = array('Form', 'Html', 'Javascript', 'Time');
}
?>

Creating Helpers¶

If a core helper (or one showcased on Cakeforge or the Bakery) doesn’t fit your needs, helpers are easy to create.

Let’s say we wanted to create a helper that could be used to output a specifically crafted CSS-styled link you needed many different places in your application. In order to fit your logic in to CakePHP’s existing helper structure, you’ll need to create a new class in /app/views/helpers. Let’s call our helper LinkHelper. The actual PHP class file would look something like this:

<?php
/* /app/views/helpers/link.php */

class LinkHelper extends AppHelper {
    function makeEdit($title, $url) {
        // Logic to create specially formatted link goes here...
    }
}

?>

There are a few methods included in CakePHP’s Helper class you might want to take advantage of:

output(string $string)

Use this function to hand any data back to your view.

<?php
function makeEdit($title, $url) {
    // Use the helper's output function to hand formatted
    // data back to the view:
    return $this->output(
        "<div class=\"editOuter\">
         <a href=\"$url\" class=\"edit\">$title</a>
         </div>"
    );
}
?>

<?php
/* /app/views/helpers/link.php (using other helpers) */
class LinkHelper extends AppHelper {
    var $helpers = array('Html');

    function makeEdit($title, $url) {
        // Use the HTML helper to output
        // formatted data:

        $link = $this->Html->link($title, $url, array('class' => 'edit'));

        return $this->output("<div class=\"editOuter\">$link</div>");
    }
}
?>

<!-- Einen Link mittels des neuen Helpers erstellen -->
<?php echo $link->makeEdit('Change this Recipe', '/recipes/edit/5') ?>

Eigene Funktionen für alle Helper erstellen¶

Alle Helper erweitern (extend) die Klasse AppHelper (genauso, wie Modelle die Klasse appModel erweitern und Controller die Klasse AppController). Um nun eine Funktion für alle Helper zu erstellen, erstelle einfach eine AppHelper-Klasse in /app/app_helper.php.

<?php
class AppHelper extends Helper {
    function customMethod () {
    }
}
?>

System Helper¶

In CakePHP sind bereits einige Helper vorinstalliert, die dir bei der Erstellen von Views helfen werden. Sie unterstüzten dich beim Schrebien von wohlgeformten (well-formed) Markup, beim Formatieren von Text, Zeiten und Zahlen. Sie können sogar die Geschwindigkeit deiner Ajax-Anwendungen erhöhen. Hier ist eine Auflistung aller vorinstallieren Helper. Für mehr Informationen siehe: Core Helpers.