How to make a view helper - php

Question

...//
EDIT:
I have resolved my problem and I want to share the solution.
The better way to make a Zend Framework 2 Helper:
Step 1.
<?php
//file : App_folder/module/Module_name/src/Module_name/View/Helper/SayHello.php
namespace Application\View\Helper;
use Zend\View\Helper\AbstractHelper;
class SayHello extends AbstractHelper{
public function __invoke($name = 'Unnamed'){
return "Hello $name,";
}
}
?>
Step 2.
<?php
//file : App_folder/module/Module_name/Module.php
public function getViewHelperConfig()
{
return array(
'factories' => array(
// the array key is the name of the invoke function that is called from view
'sayHello' => function($name) {
return new SayHello($name);
},
),
);
}
?>
Step 3.
<?php
//file : App_folder/module/Module_name/view/Module_name/index/index.phtml
$this->sayHello('Dimitri');
?>
Thanks you all for your helping.

Answer 1

Creating a ViewHelper is a simple task and it is divided in 2-3 steps, depending on your needs. Always the first step is to actually create a ViewHelper and that's where you have to make your first decisions.
Does your ViewHelper have dependencies? If yes, you'll need a __construct() function
Does your ViewHelper need arguments? If yes, you'll need to have arguments for your __invoke() function
Once you've evaluated both points, you write the ViewHelper
<?php
// FileName: /module/Application/src/Application/View/Helper/MyHelper.php
namespace Application\View\Helper;
use Zend\View\Helper\AbstractHelper;
class MyHelper extends AbstractHelper
{
// If you have dependencies:
public function __construct(DependencyInterface $dependency)
{
// store dependency as a local property inside class
}
// Put arguments if you need them, if not leave them blank
public function __invoke($arg1, $arg2, ..., $argN)
{
// Have a string being returned directly
// return 'some string';
// Or you could return a rendered view template and pass view variables
// return $this->getView()->render('foo/bar', array(
// $arg1, $arg2, ..., $argN
// ));
}
}
The second thing you have to do is to register this ViewHelper to the ViewHelperManager. If you have no dependencies, you put it up under the invokables configuration, if you do have dependencies, it will become a factories entry.
public function getViewHelperConfig()
{
return array(
'invokables' => array(
'MyHelper' => 'Application\View\Helper\MyHelper'
),
// or if it has dependencies
'factories' => array(
'MyHelper' => function($viewHelperManager) {
$serviceLocator = $viewHelperManager->getServiceLocator();
$dependency = $serviceLocator->get('SomeDependency');
return new MyHelper($dependency);
}
)
);
}
And then you're able to use your ViewHelper via $this->myHelper() inside your view files. Btw it doesn't matter if you camelcase your configuration for the ViewHelper name because it will be lower-cased internally. So $this->MyHelper() equals $this->myhelper() and MyHelper equals myhelper.