Integrate and use zend framework 2 with codeigniter

Zend framework 2(ZF2) is an open source framework using PHP 5.3+ with more than 15 million downloads. It should be kept in mind that ZF2 is not backward compatible with ZF1. ZF2 has an unique component structure and each component only have few dependencies on other components. Simply Zend call this architecture as "use-at-will" design.


If you want to integrate Codeigniter and ZF2 then that's a good idea. I assume that you have downloaded both codeigniter and ZF2. Help on installing Zend Framework 2 in ubuntu can be found here.

Now as the two frameworks are downloaded, copy the Zend folder(under library) from Zend download to application/libraries in Codeigniter. The idea here is to use the Zend components as a library in Codeigniter. Lets see an example of using Zend Captcha in Codeigniter.

First we need to create a new file under application/libraries, lets call it "Zend". After creating this file and open it in a text editor and copy paste the following code:

Zend.php

require_once 'autoload.php';
class Zend{

public $obj;
public $objId;

public function __construct(){

}


public function createImageCaptcha($params=array()){
$this->obj = new Zend\Captcha\Image( array(
  'imgDir'=>'public/',
  'font' => 'font/opensans-regular-webfont.ttf',
  'width' => 250,
  'height' => 100,
  'dotNoiseLevel' => 40,
  'lineNoiseLevel' => 3)
);
$this->obj->generate();
return $this->obj;
}

}

In the constructor i am just including the corresponding class file from Zend. The function createImageCaptcha() actually creates an image of type png inside the path you specify, imgDir variable sets the file path and font variable sets the font path. Remember that the paths are relative your root folder. Here what i am trying to do is to create my own wrapper to the Zend components instead of calling them directly in controller. In my controller i would access my Zend Captcha as follows:

$this->load->library('zend');
$captcha = $this->zend->createImageCaptcha();


Here $captcha is an object and will hold all the information regarding the Captcha.  $captcha->getimgDir()  would give you the image directory, $captcha->getId() would give you the filename, $captcha->getsuffix() would give you the file extension and so on. All the properties can be accessed by just appending "get" to them. 

At last but not least we need to know about the file named "autoload.php" which is included in the top. The purpose of this file is to autoload all the dependency files in Zend while instantiating an object. If this file is not present then an error like the following may appear "Fatal error: Class 'Zend\Captcha\AbstractWord' not found", in case of Captcha component. Same  will be the case with all components in Zend. So instead of updating every file with include directive we autoload all the dependent files. 

autoload.php

namespace Zend;
spl_autoload_register(function ($class) {
    if (substr($class, 0, strlen(__NAMESPACE__)) != __NAMESPACE__) {
        //Only autoload libraries from this package
        return;
    }
    $path = substr(str_replace('\\', '/', $class), 0);
    $path = __DIR__ . "/".$path . '.php';
    if (file_exists($path)) {
        require $path;
    }

});

The main purpose of this article is to explain how to use ZF2 modules along with Codeigniter. Hope this article was helpfull. If you find this information incorrect please don't hesitate to comment. There is also an alternative by using the third_party option in Codeigniter.