Zend 2 Dynamic Content in Layout with View Helpers - php

Question

I'm new in Zend FW 2 and I try to showing data from database in layout but I receive error:
Catchable fatal error: Argument 1 passed to Application\View\Helper\HotNews::__construct() must be an instance of Zend\Db\Adapter\Adapter, none given, called in C:\xampp\htdocs\webtruonghoc\vendor\ZF2\library\Zend\ServiceManager\AbstractPluginManager.php on line 207 and defined in C:\xampp\htdocs\webtruonghoc\module\Application\src\Application\View\Helper\HotNews.php on li
Function getViewHelperConfig in Module.php:
public function getViewHelperConfig()
{
return array(
'factories' => array(
'hotNews' => function($sm) {
$adapter = $sm->getServiceLocator()->get('Application\Model\NewsTable');
return new HotNews($adapter);
},
),
);
}
Add code in module.config.php:
'view_helpers' => array(
'invokables' => array(
'hotnews' => 'Application\View\Helper\HotNews',
),
File HotNews.php:
<?php
namespace Application\View\Helper;
use Zend\Authentication\AuthenticationService;
use Zend\View\Helper\AbstractHelper;
use Zend\Db\Adapter\Adapter;
class HotNews extends AbstractHelper
{
protected $adapter;
public function __construct(Adapter $adapter)
{
$this->adapter = $adapter;
}
public function __invoke()
{
$sql="SELECT * FROM news order by date DESC limit 0,4";
return $resultSet = $this->adapter->query($sql, \Zend\Db\Adapter\Adapter::QUERY_MODE_EXECUTE);
}
}
and final I showing data in layout:
<?php $hotnews = $this->hotNews();
var_dump($hotnews);
?>
Do I miss something?

Answer 1

It looks like you are expecting your model to be set up as a service. but may not have set up the service correctly. In your module.config.php file, there should be an entry under 'service_manager' => 'factories' :
return array(
'service_manager' => array(
'factories' => array(
'Application\Model\NewsTable' => function (ServiceLocatorInterface $serviceLocator) {
//... returns an instance of Application\Model\NewsTable
}
)
)
);
Your SQL has an error in it. Also, you should not be executing SQL statements inside a view helper, and passing the entire result set of a select * to the view is bad JuJu as well. I would place the SQL inside a Repository class which returns DTO objects representing your data model. You could then inject the repository into your ViewHelper and and use those DTOs in your view.