CodeIgniter Minifier - A HTML / CSS / Javascript Minification Library

Compress and minify output for your CodeIgniter framework websites. This library supports CodeIgniter 3 only, it is able to not just minify HTML, but also CSS and Javascript.

It also works with $this->output->cache($n); to save minified content into the cache files.

Change Logs

ver 1.0 - first release
ver 1.1 - Add javascript obfuscator (Dean Edwards' version)
ver 1.2 - Add PHP Simple Dom parser to parse "script" and "style" tags. It is an alternative if the default parser (DOMDocument) causes your Javasctipt to not work.

Step 1: Load CI_Minifier library

Copy CI_Minifier.php to libraries folder, and then load CI_Minifier library by one of the following ways.

(1) Load CI_Minifier library in Controller.

$this->load->library('CI_Minifier');

(2) Load CI_Minifier library in config/autoload.php (recommeded)

$autoload['libraries'] = array('CI_Minifier');

Step 2: Enable Hooks in config/config.php

$config['enable_hooks'] = TRUE;

Step 3: Define a 'display_override' to config/hooks.php

$hook['display_override'][] = array(
    'class' => '',
    'function' => 'CI_Minifier_Hook_Loader',
    'filename' => '',
    'filepath' => ''
);

Keep "class", "filename" and "filepath" fields blank.

Options

CodeIgniter Minifier has the following options, you can set the "option number" or "option string" to init() to minify HTML, CSS, Javascript as your choice.

For setting option string, you can put them together and separated by commas, for example: 'html,js'

option number	option string	HTML	CSS	Javascript
0	off	x	x	x
1	html,css,js	o	o	o
2	html,css	o	o	x
3	html,js	o	x	o
4	html	o	x	x
5	css,js	x	o	o
6	css	x	o	x
7	js	x	x	o

Notice that setting option to '1' or 'html,css,js' is totally unnecessary, because it is default.

Here is the examples:

// Keep original output, nothing changes. You can use it on some pages you won't minify.
$this->ci_minifier->init(0);
// same as
$this->ci_minifier->init('off');

// Minify html only
$this->ci_minifier->init(4); 
// same as
$this->ci_minifier->init('html');

// Minify html and css, except jaascript
$this->ci_minifier->init(2);
// same as
$this->ci_minifier->init('html,css');

Enable Javascript obfuscator

enable_obfuscator($level = 2)

/**
 * @param int $level - default: 2
 * @return bool
 */
$this->ci_minifier->enable_obfuscator();

option level	obfuscation type
0	None
1	Numeric
2	Normal
3	High ASCII

Javascript obfuscator is off by default, if you would like to use this feature, copy JSPacker.php to /application/third_party/ folder, then put $this->ci_minifier->enable_obfuscator(); in Controller.

Use PHP Simple Dom parser to parse "script" and "style" tags

put Simple_html_dom.php at /third_party folder
use $this->ci_minifier->set_domparser(2); in Controller.

option value: 1 (default, PHP bulti-in Dom parser - DOMDocument) option value: 2 (PHP Simple Dom parser)

API

html()

Minify HTML string

/**
 * @param $input
 * @return string
 */
$this->ci_minifier->html($input);

css()

Minify CSS string

/**
 * @param $input
 * @return string
 */
$this->ci_minifier->css($input);

js()

Minify Javascript string

/**
 * @param $input
 * @return string
 */
$this->ci_minifier->js($input);

Be careful: This method doesn't support "javascript automatic semicolon insertion", you must add semicolon by yourself, otherwise your javascript code will not work and generate error messages.

js_packer()

Minify Javascript string by use JSPacker (Dean Edwards' version)

/**
 * @param $input
 * @param $level
 * @return string
 */
$this->ci_minifier->js($input, $level = 2);

Success example

Original code:

<script>
var d = new Date();
d.setTime(d.getTime()+(7*24*60*60*1000));
var expires = "expires="+d.toUTCString();
document.cookie = "ssjd=1;domain=.dictpedia.com;"+expires;
</script>

After minifying

<script>var d=new Date();d.setTime(d.getTime()+(7*24*60*60*1000));var expires="expires="+d.toUTCString();document.cookie="ssjd=1;domain=.dictpedia.com;"+expires;</script>

Failure example

Original code is working with popular browsers because that browsers support "javascript automatic semicolon insertion".

<script>
var d = new Date()
d.setTime(d.getTime()+(7*24*60*60*1000))
var expires = "expires="+d.toUTCString()
document.cookie = "ssjd=1;domain=.dictpedia.com;"+expires;
</script>

After minifying, this code will generate error because of semicolon issue.

<script>var d=new Date()d.setTime(d.getTime()+(7*24*60*60*1000))var expires="expires="+d.toUTCString()document.cookie="ssjd=1;domain=.dictpedia.com;"+expires;</script>

Ideas

Minifying all Javascript snippets is good but it breaks Google AdSense's TOS, so how to minify all of them excepts Google AdSense?

<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
<ins class="adsbygoogle"
     style="display:inline-block;width:160px;height:600px"
     data-ad-client="ca-pub-xxxxxxxxxx"
     data-ad-slot="4179732317"></ins>
<script data-minify-level="0">
(adsbygoogle = window.adsbygoogle || []).push({});
</script>

CI Minifier will skip script tags contain data-minify-level="0", this option can also control Javascript obfuscator encoding level, the default value is 2, you set the value 1-3 whatever you like.

License

GPL version 3

0x1881 / codeigniter-minifier