View helper plugin extending in ZF2

Question

I want to extend, for example, Zend\\View\\Helper\\HeadMeta with my own class and I create a factory for it and call it by

public function getViewHelperConfig()
{
    return array(
        'factories' => array(
            'MyHeadMeta' => __NAMESPACE__ . '\View\Helper\Service\MyHeadMetaService',
        ),
    );
}

from Module.php , but I have

$this->view

is null in MyHeadMeta class if I call it by

$this->MyHeadMeta()->setCharset('utf-8');

in my view file.

How do I instantiate my view helper properly?

UPDATE

My class looks something like this:

MyHeadMeta.php

use Zend\View\Helper\HeadMeta;

class MyHeadMeta extends HeadMeta
{
    //
}

UPDATE 2

MyHeadMetaService.php

class MyHeadMetaService implements FactoryInterface
{
    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        $viewHelper = new MyHeadMeta();
        // some settings to set...
        return $viewHelper;
    }
}

Answer 1

If you only extend the existing HeadMeta class then you should register it as an invokable as is done with the original HeadMeta view helper in the HelperPluginManager .

So change your config like this:

return array(
    'invokables' => array(
        'MyHeadMeta' => 'View\Helper\Service\MyHeadMetaService'
    )
);

By the way I don't think it is necessary to use the full path with __NAMESPACE__ . Just make sure the name points to the correct file and folder path of your class in the current module and declare the namespace constant in the class.