CodeIgniter CDN integration

Before you start

  • Before you take any steps please back up your files and database.
  • In the following, we will integrate a CDN service using the CDN domain 12345.r.cdnsun.net. Please visit the Services/How-To section to obtain your CDN domain.
  • To integate a CDN service on https:// website you can use https://12345.r.cdnsun.net or you can use a custom CDN domain with SSL enabled.
  • If your website embeds custom fonts then please first enable CORS for them.
  • Before you take any steps please make sure that your CDN domain is ready-to-use here.

Create CDN Static service

Please refer to Creating a CDN Static service for more details.

Enable CDN in CodeIgniter

Define CDN in config

Add the following to the CodeIgniter's applicaiton/config/config.php file.

$config['cdn_enabled']  = true;
$config['cdn_domain']   = '12345.r.cdnsun.net';
$config['cdn_protocol'] = 'http';

Create CDN helper

Create a file application/helpers/cdn_helper.php with the following content.

<?php

function cdn($url = null)
{
    $url = (string) $url;
    if(empty($url))
    {
        throw new Exception('URL missing');
    }

    $pattern = '|^http[s]{0,1}://|i';        
    if(preg_match($pattern, $url))
    {
        throw new Exception('Invalid URL. ' .
            'Use: /image.jpeg instead of full URI: ' .
            'http://domain.com/image.jpeg.'
        );
    }
        
    $pattern = '|^/|';        
    if(!preg_match($pattern, $url))
    {
        $url = '/' . $url;
    }

    $currentInstance    =& get_instance();
    $cdn_enabled        = $currentInstance->config->item('cdn_enabled');
    $cdn_domain         = $currentInstance->config->item('cdn_domain');
    $cdn_protocol       = $currentInstance->config->item('cdn_protocol');

    if(empty($cdn_enabled))
    {
        return $url;
    }
    else
    {
        return $cdn_protocol . '://' . $cdn_domain . $url;
    }    
}

Update autoloader

Add the following to the CodeIgniter's application/config/autoload.php file.

$autoload['helper'] = array('cdn');

Use the CDN helper in views

<? echo cdn('/image.jpeg'); ?>

will output

http://12345.r.cdnsun.net/image.jpeg

Notes

  • View HTML source code of your web pages to verify that you are using CDN, you should see source attribute of your images, CSS, JavaScript, etc. beginning with your CDN domain.
  • Don't see your CDN domain in source code of your web pages? If your website is using any cache plug-in/mechanism then you might want to clear/flush its cache.
  • Having troubles with custom fonts? Please refer to Using custom fonts with CDN - setting CORS for more details.
  • Still having troubles? Check your CDN URLs in our CDN content check or please refer to Debugging a CDN service for more hints.

Contact Us

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