Zend Framework – create custom view helper

Zend Framework is not as popular as Symfony, but it’s also nice and have a lot of nice features. One of them is view helpers – classes and objects which we can use in templates to make specific thinks. Zend has few build-in helpers, for example to use absolute app directory, set or receive HTML doctype, use partials templates or use authentication data. Sometimes we can (or maybe should) create our view helper to avoid repetition of the code. It’s simple, let’s try.

When and why should we create our view helpers?

When we should create our view helper? It’s simple: always, when we can move some repeated code – instead of using it in many templates, write only once in helper class. Simple example can be something to create thumbnails on our application templates. We have array with images and names for titles and want create grid with that images. Of course, we can use the same code in many places, but what we we have to change it? We must check and change it in any place – yes, we can use search and replace, but sometimes is not enough. Better choice is to create helper and use it in only one line. If we must change something, just change in class, not in many templates.

Create helper class

First, we must create helper class, for example in one of or modules – say MyModule/src/MyModule/View/Helper/ThumbnailsHelper.php – it will file with our class. We should extend AbstractHelper to use magic __invoke method in templates, let’s try simple example for thumbnails:

namespace MyModule\View\Helper;
use Zend\View\Helper\AbstractHelper;
 
class ThumbnailsHelper extends AbstractHelper
{
    public function __invoke(array $thumbnails, bool $withLinks = false)
    {
        $code = '<div class="thumbnailsGrid">';
        foreach ($thumbnails as $thumbnail) {
            $code .= '</div>';

            if ($withLinks) {
                $code .= '<a href="' . $thumbnail['link'] . '">';
            }
            $code .= '<img src="' . $thumbnail['img'] . '" alt="' . $thumbnail['name'] . '" />';
            if ($withLinks) {
                $code .= '</a>';
            }

            $code .= '</div>'
        }
        $code .= '</div>'
 
        return $code;
    }
}

 

Register our helper

Of course we can do the same using partials templates – and in many cases it will be better choice, but it’s only example. Second think is to register our view helper in our module. Without that, Zend will not allow us to use magic function in templates. Edit file MyModule/module.config.php and add code for our new helper:

return array(
    // There is our module config data

    // There are all helpers
    'view_helpers' => array(
        'invokables' => array(
            'ThumbnailsHelper' => 'MyModule\View\Helper\ThumbnailsHelper',
        )
    )
);

 

Use helper in templates

Save and… it’s all. We can now use view helper in our templates:

<?= $this->ThumbnailsHelper($thumbnail); ?>

 

What about using view helpers in controllers? It’s possible, but not recommended, because we must use ServiceLocator to get our helper (and ServiceLocatorAwareInterface is deprecated from Zend Framework 3). We should use it only in templates.

3 thoughts on “Zend Framework – create custom view helper

  1. if i want do write query here with help of query builder how to get servermanager and entitymanager enstance zend 3

    1. Not sure because I work with “legacy” project (updated from ZF2 to ZF3) but I think you can use three options:

      1. Provide servicemanager as view helper attribute (bad solution)
      2. Use something like central registry for servicemanager and get it using static method (also, bad option)
      3. Write your custom factory class to create view helper and set it in module.config.php – you can use servicemanager and inject all dependencies in such factory (it’s the best option)

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