PHP magic method __invoke, empty instance variables - php

Question

I'm facing a problem when calling __invoke() on an object. Is __invoke() method agnostic to instance variables? I need to call __invoke() directly on my templates due to some ZF2 injection to call $this->getView()->render(...) (otherwise getView() returns null) and I would like to have instance variables setted there. Any workaround?
See my code:
namespace Person\Person\View\Helper;
use Zend\View\Helper\AbstractHelper;
class PersonShowWidget extends AbstractHelper
{
protected $model = null;
public function __construct(array $options = null)
{
$this->parseOptions($options);
}
public function __invoke()
{
var_dump($this->model); //returns null
return $this->getView()->render('person/show/show_widget', array(
'title' => 'Cliente',
'model' => $this->model,
)
);
}
public function setOptions(array $options = null)
{
$this->parseOptions($options);
}
protected function parseOptions(array $options = null)
{
if (!is_null($options) && is_array($options)) {
if (isset($options['model'])) {
$model = $options['model'];
if (isset($model['id'])) {
$this->model['id'] = $model['id'];
} else {
throw new \Exception;
}
if (isset($model['form'])) {
$this->model['form'] = $model['form'];
} else {
throw new \Exception;
}
}
}
var_dump($this->model); //returns valid data
}
}
I do have called the constructor with some options or the setOptions method before calling __invoke().
Thanks,

Answer 1

You have to initialize the view helper with a factory. In this way you can make sure the constructor is called before the __invoke method is called. And no..the __invoke() method is not agnostic to instance variables.
In the Module.php
public function getViewHelperConfig()
{
return array(
'factories' => array(
'personShowWidget' => function ($helpers) {
$array = array();
$helper = new Person\Person\View\Helper\PersonShowWidget($array);
return $helper;
},
)
);
}
Or in the module.config.php
'view_helpers' => array
(
'factories' => array(
'personShowWidget' => function ($helpers) {
$array = array();
$helper = new Person\Person\View\Helper\PersonShowWidget($array);
return $helper;
},
)
)
Performance-wise you'd better make a Factory class instead of a callable.
More info: http://framework.zend.com/manual/2.0/en/modules/zend.module-manager.module-manager.html
Edit:
It seems like you using the ViewHelper wrongly. You don't have to create the instance by yourself. Just use the ViewHelper in the view. So why not just give the $options as parameter to the __invoke method?
public function __invoke(array $options = null)
{
$this->setOptions($options);
return $this->getView()->render('person/show/show_widget', array(
'title' => 'Cliente',
'model' => $this->model,
)
);
}
In the Controller pass the options array to the view:
return array(
'options' => $options,
);
And call the ViewHelper in the view:
<?php echo $this->personShowWidget($this->options); ?>
Remember: In this way you don't need a Factory to init the ViewHelper. Just add it to the invokables.
module.config.php example:
'view_helpers' => array(
'invokables' => array(
'personShowWidget' => 'Person\Person\View\Helper\PersonShowWidget',
),
),