plugin-minify-resource-output.php

<?php
/**
 * 
 * Plugin fires OnWebPagePrerender system event, loads Minify HTML by Mr Clay and minifies the requested Resource HTML inc. inline css and js.
 * 
 * If used in conjunction with StatCache the minified HTML is cached and served as a flat file via IIS Rewrite.
 * 
 * CREDITS
 * 
 * http://rtfm.modx.com/revolution/2.x/developing-in-modx/basic-development/plugins
 * http://forums.modx.com/thread/69932/full-page-caching---is-it-achievable
 * http://ttyl.modx.com/thread/69839/using-modx--gt-cachemanager--gt-refresh-with-custom-components#dis-post-391711
 * http://forums.modx.com/thread/29643/tidy-plugin-fetch-the-document-output
 * 
 * DEPENDENCIES
 * 
 * https://github.com/mrclay/minify - set to use version bundled with MODX core (/manager/min) with MODX_MANAGER_PATH
 *  
 * AUTHOR
 *
 * chris@cubewebworks.co.uk
 * 
 **/



switch ($modx->event->name) {           // switch not required, plugin only fires on one event OnWebPagePrerender
    case 'OnWebPagePrerender':
        
        $output             = $modx->resource->_output;
        $initial_bytes      = strlen($output);
        // $minify_lib_path    = $modx->config['base_path'] . 'min/';       // this is for manually installed version of min
        $minify_lib_path    = $modx->config['manager_path'] . 'min/';       // this is for min version bundled with MODX
        
        if (!class_exists('Minify_HTML')) {
            // Two lines below to register Minify Loader are only applicable if using minify v2.1.7
            // require("$minify_lib_path/lib/Minify/Loader.php");
            // Minify_Loader::register();
            
            ini_set('include_path', ini_get('include_path') . ":$minify_lib_path/lib");     // required? test without
            
            require_once("$minify_lib_path/lib/Minify/HTML.php");
            require_once("$minify_lib_path/lib/Minify/CSS.php");
            require_once("$minify_lib_path/lib/JSMin.php");
            
            // also include comment preserver because of error without /*[13-Aug-2015 17:41:17 UTC] PHP Fatal error:  require_once(): Failed opening required 'C:/path/to/hosts/domain.co.uk/httpdocs/min//lib/CommentPreserver.php' (include_path='.;.\includes;.\pear:C:/path/to/hosts/domain.co.uk/httpdocs/min//lib')*/
            require_once("$minify_lib_path/lib/Minify/CommentPreserver.php");
        }
        
        // call minify HTML function and minify inline CSS and JS
        $output = Minify_HTML::minify($output, array(
            'cssMinifier' => array(
                'Minify_CSS',
                'minify'
            ),
            'jsMinifier' => array(
                'JSMin',
                'minify'
            )
        ));
        
        // calculate savings
        $final_bytes = strlen($output);
        $saved_bytes = ($initial_bytes - $final_bytes);
        $savings = round((($initial_bytes - $final_bytes) / $initial_bytes * 100), 3);
        
        // tag bytes saved comment to end out output
        $output .= PHP_EOL . "<!-- [HTML Minification] Uncompressed: $initial_bytes bytes; Compressed: $final_bytes bytes; $saved_bytes bytes ($savings%) saved. -->";
        
        $modx->resource->_output = $output;
        
        break;
}