Component-Builder/admin/helpers/minify.php

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2016-01-30 20:28:43 +00:00
<?php
/*--------------------------------------------------------------------------------------------------------| www.vdm.io |------/
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/-------------------------------------------------------------------------------------------------------------------------------/
@version 2.3.5
@build 22nd February, 2017
2016-01-30 20:28:43 +00:00
@created 30th April, 2015
@package Component Builder
@subpackage minify.php
@author Llewellyn van der Merwe <http://vdm.bz/component-builder>
2016-01-30 20:28:43 +00:00
@copyright Copyright (C) 2015. All Rights Reserved
@license GNU/GPL Version 2 or later - http://www.gnu.org/licenses/gpl-2.0.html
Builds Complex Joomla Components
/-----------------------------------------------------------------------------------------------------------------------------*/
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
/**
* Abstract minifier class.
*
* Please report bugs on https://github.com/matthiasmullie/minify/issues
*
* @author Matthias Mullie <minify@mullie.eu>
*
* @copyright Copyright (c) 2012, Matthias Mullie. All rights reserved.
* @license MIT License
*/
abstract class Minify
{
/**
* The data to be minified
*
* @var string[]
*/
protected $data = array();
/**
* Array of patterns to match.
*
* @var string[]
*/
protected $patterns = array();
/**
* This array will hold content of strings and regular expressions that have
* been extracted from the JS source code, so we can reliably match "code",
* without having to worry about potential "code-like" characters inside.
*
* @var string[]
*/
public $extracted = array();
/**
* Init the minify class - optionally, code may be passed along already.
*/
public function __construct(/* $data = null, ... */)
{
// it's possible to add the source through the constructor as well ;)
if (func_num_args()) {
call_user_func_array(array($this, 'add'), func_get_args());
}
}
/**
* Add a file or straight-up code to be minified.
*
* @param string $data
*/
public function add($data /* $data = null, ... */)
{
// bogus "usage" of parameter $data: scrutinizer warns this variable is
// not used (we're using func_get_args instead to support overloading),
// but it still needs to be defined because it makes no sense to have
// this function without argument :)
$args = array($data) + func_get_args();
// this method can be overloaded
foreach ($args as $data) {
// redefine var
$data = (string) $data;
// load data
$value = $this->load($data);
$key = ($data != $value) ? $data : count($this->data);
// store data
$this->data[$key] = $value;
}
}
/**
* Load data.
*
* @param string $data Either a path to a file or the content itself.
* @return string
*/
protected function load($data)
{
// check if the data is a file
if (@file_exists($data) && is_file($data)) {
$data = @file_get_contents($data);
// strip BOM, if any
if (substr($data, 0, 3) == "\xef\xbb\xbf") {
$data = substr($data, 3);
}
}
return $data;
}
/**
* Save to file
*
* @param string $content The minified data.
* @param string $path The path to save the minified data to.
* @throws Exception
*/
protected function save($content, $path)
{
// create file & open for writing
if (($handler = @fopen($path, 'w')) === false) {
throw new Exception('The file "'.$path.'" could not be opened. Check if PHP has enough permissions.');
}
// write to file
if (@fwrite($handler, $content) === false) {
throw new Exception('The file "'.$path.'" could not be written to. Check if PHP has enough permissions.');
}
// close the file
@fclose($handler);
}
/**
* Minify the data & (optionally) saves it to a file.
*
* @param string[optional] $path Path to write the data to.
* @return string The minified data.
*/
public function minify($path = null)
{
$content = $this->execute($path);
// save to path
if ($path !== null) {
$this->save($content, $path);
}
return $content;
}
/**
* Minify & gzip the data & (optionally) saves it to a file.
*
* @param string[optional] $path Path to write the data to.
* @param int[optional] $level Compression level, from 0 to 9.
* @return string The minified & gzipped data.
*/
public function gzip($path = null, $level = 9)
{
$content = $this->execute($path);
$content = gzencode($content, $level, FORCE_GZIP);
// save to path
if ($path !== null) {
$this->save($content, $path);
}
return $content;
}
/**
* Minify the data.
*
* @param string[optional] $path Path to write the data to.
* @return string The minified data.
*/
abstract protected function execute($path = null);
/**
* Register a pattern to execute against the source content.
*
* @param string $pattern PCRE pattern.
* @param string|callable $replacement Replacement value for matched pattern.
* @throws Exception
*/
protected function registerPattern($pattern, $replacement = '')
{
// study the pattern, we'll execute it more than once
$pattern .= 'S';
$this->patterns[] = array($pattern, $replacement);
}
/**
* We can't "just" run some regular expressions against JavaScript: it's a
* complex language. E.g. having an occurrence of // xyz would be a comment,
* unless it's used within a string. Of you could have something that looks
* like a 'string', but inside a comment.
* The only way to accurately replace these pieces is to traverse the JS one
* character at a time and try to find whatever starts first.
*
* @param string $content The content to replace patterns in.
* @return string The (manipulated) content.
*/
protected function replace($content)
{
$processed = '';
$positions = array_fill(0, count($this->patterns), -1);
$matches = array();
while ($content) {
// find first match for all patterns
foreach ($this->patterns as $i => $pattern) {
list($pattern, $replacement) = $pattern;
// no need to re-run matches that are still in the part of the
// content that hasn't been processed
if ($positions[$i] >= 0) {
continue;
}
$match = null;
if (preg_match($pattern, $content, $match)) {
$matches[$i] = $match;
// we'll store the match position as well; that way, we
// don't have to redo all preg_matches after changing only
// the first (we'll still know where those others are)
$positions[$i] = strpos($content, $match[0]);
} else {
// if the pattern couldn't be matched, there's no point in
// executing it again in later runs on this same content;
// ignore this one until we reach end of content
unset($matches[$i]);
$positions[$i] = strlen($content);
}
}
// no more matches to find: everything's been processed, break out
if (!$matches) {
$processed .= $content;
break;
}
// see which of the patterns actually found the first thing (we'll
// only want to execute that one, since we're unsure if what the
// other found was not inside what the first found)
$discardLength = min($positions);
$firstPattern = array_search($discardLength, $positions);
$match = $matches[$firstPattern][0];
// execute the pattern that matches earliest in the content string
list($pattern, $replacement) = $this->patterns[$firstPattern];
$replacement = $this->replacePattern($pattern, $replacement, $content);
// figure out which part of the string was unmatched; that's the
// part we'll execute the patterns on again next
$content = substr($content, $discardLength);
$unmatched = (string) substr($content, strpos($content, $match) + strlen($match));
// move the replaced part to $processed and prepare $content to
// again match batch of patterns against
$processed .= substr($replacement, 0, strlen($replacement) - strlen($unmatched));
$content = $unmatched;
// first match has been replaced & that content is to be left alone,
// the next matches will start after this replacement, so we should
// fix their offsets
foreach ($positions as $i => $position) {
$positions[$i] -= $discardLength + strlen($match);
}
}
return $processed;
}
/**
* This is where a pattern is matched against $content and the matches
* are replaced by their respective value.
* This function will be called plenty of times, where $content will always
* move up 1 character.
*
* @param string $pattern Pattern to match.
* @param string|callable $replacement Replacement value.
* @param string $content Content to match pattern against.
* @return string
*/
protected function replacePattern($pattern, $replacement, $content)
{
if (is_callable($replacement)) {
return preg_replace_callback($pattern, $replacement, $content, 1, $count);
} else {
return preg_replace($pattern, $replacement, $content, 1, $count);
}
}
/**
* Strings are a pattern we need to match, in order to ignore potential
* code-like content inside them, but we just want all of the string
* content to remain untouched.
*
* This method will replace all string content with simple STRING#
* placeholder text, so we've rid all strings from characters that may be
* misinterpreted. Original string content will be saved in $this->extracted
* and after doing all other minifying, we can restore the original content
* via restoreStrings()
*
* @param string[optional] $chars
*/
protected function extractStrings($chars = '\'"')
{
// PHP only supports $this inside anonymous functions since 5.4
$minifier = $this;
$callback = function ($match) use ($minifier) {
if (!$match[1]) {
/*
* Empty strings need no placeholder; they can't be confused for
* anything else anyway.
* But we still needed to match them, for the extraction routine
* to skip over this particular string.
*/
return $match[0];
}
$count = count($minifier->extracted);
$placeholder = $match[1].$count.$match[1];
$minifier->extracted[$placeholder] = $match[1].$match[2].$match[1];
return $placeholder;
};
/*
* The \\ messiness explained:
* * Don't count ' or " as end-of-string if it's escaped (has backslash
* in front of it)
* * Unless... that backslash itself is escaped (another leading slash),
* in which case it's no longer escaping the ' or "
* * So there can be either no backslash, or an even number
* * multiply all of that times 4, to account for the escaping that has
* to be done to pass the backslash into the PHP string without it being
* considered as escape-char (times 2) and to get it in the regex,
* escaped (times 2)
*/
$this->registerPattern('/(['.$chars.'])(.*?((?<!\\\\)|\\\\\\\\+))\\1/s', $callback);
}
/**
* This method will restore all extracted data (strings, regexes) that were
* replaced with placeholder text in extract*(). The original content was
* saved in $this->extracted.
*
* @param string $content
* @return string
*/
protected function restoreExtractedData($content)
{
if (!$this->extracted) {
// nothing was extracted, nothing to restore
return $content;
}
$content = strtr($content, $this->extracted);
$this->extracted = array();
return $content;
}
}