<?php
/**
* 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
*/
namespace PHPFusion\Minify;
use PHPFusion\Minify\Exceptions\IOException;
use PHPFusion\Minify\Cache\CacheItemInterface;
/**
* Abstract minifier class.
*
* Please report bugs on https://github.com/matthiasmullie/minify/issues
*
* @package Minify
* @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 of patterns to match.
*
* @var string[]
*/
protected $patterns = [];
/**
* 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 = [];
/**
* Init the minify class - optionally, code may be passed along already.
*/
public function __construct(/* $data = null, ... */) {
// it's possible to add the source through the constructor as well ;)
if (func_num_args()) {
call_user_func_array([$this, 'add'], func_get_args());
}
}
/**
* Add a file or straight-up code to be minified.
*
* @param string|string[] $data
*
* @return static
*/
public function add($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 :)
$args = [$data] + func_get_args();
// this method can be overloaded
foreach ($args as $data) {
if (is_array($data)) {
call_user_func_array([$this, 'add'], $data);
continue;
}
// redefine var
$data = (string)$data;
// load data
$value = $this->load($data);
$key = ($data != $value) ? $data : count($this->data);
// replace CR linefeeds etc.
// @see https://github.com/matthiasmullie/minify/pull/139
$value = str_replace(["\r\n", "\r"], "\n", $value);
// store data
$this->data[$key] = $value;
}
return $this;
}
/**
* Add a file to be minified.
*
* @param string|string[] $data
*
* @return static
*
* @throws IOException
*/
public function addFile($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 :)
$args = [$data] + func_get_args();
// this method can be overloaded
foreach ($args as $path) {
if (is_array($path)) {
call_user_func_array([$this, 'addFile'], $path);
continue;
}
// redefine var
$path = (string)$path;
// check if we can read the file
if (!$this->canImportFile($path)) {
throw new IOException('The file "'.$path.'" could not be opened for reading. Check if PHP has enough permissions.');
}
$this->add($path);
}
return $this;
}
/**
* 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 & write it to a CacheItemInterface object.
*
* @param CacheItemInterface $item Cache item to write the data to
*
* @return CacheItemInterface Cache item with the minifier data
*/
public function cache(CacheItemInterface $item) {
$content = $this->execute();
$item->set($content);
return $item;
}
/**
* Minify the data.
*
* @param string[optional] $path Path to write the data to
*
* @return string The minified data
*/
abstract public function execute($path = NULL);
/**
* 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 ($this->canImportFile($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 $path The path to save the minified data to
*
* @throws IOException
*/
protected function save($content, $path) {
$handler = $this->openFileForWriting($path);
$this->writeToFile($handler, $content);
@fclose($handler);
}
/**
* Register a pattern to execute against the source content.
*
* @param string $pattern PCRE pattern
* @param string|callable $replacement Replacement value for matched pattern
*/
protected function registerPattern($pattern, $replacement = '') {
// study the pattern, we'll execute it more than once
$pattern .= 'S';
$this->patterns[] = [$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);
$matches = [];
while ($content) {
// find first match for all patterns
foreach ($this->patterns as $i => $pattern) {
list($pattern, $replacement) = $pattern;
// we can safely ignore patterns for positions we've unset earlier,
// because we know these won't show up anymore
if (array_key_exists($i, $positions) == FALSE) {
continue;
}
// no need to re-run matches that are still in the part of the
// content that hasn't been processed
if ($positions[$i] >= 0) {
continue;
}
$match = NULL;
if (preg_match($pattern, $content, $match, PREG_OFFSET_CAPTURE)) {
$matches[$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] = $match[0][1];
} else {
// if the pattern couldn't be matched, there's no point in
// executing it again in later runs on this same content;
// ignore this one until we reach end of content
unset($matches[$i], $positions[$i]);
}
}
// 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][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
$content = (string)substr($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
* @param string[optional] $placeholderPrefix
*/
protected function extractStrings($chars = '\'"', $placeholderPrefix = '') {
// PHP only supports $this inside anonymous functions since 5.4
$minifier = $this;
$callback = function ($match) use ($minifier, $placeholderPrefix) {
// check the second index here, because the first always contains a quote
if ($match[2] === '') {
/*
* 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 = $match[1].$placeholderPrefix.$count.$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 = [];
return $content;
}
/**
* Check if the path is a regular file and can be read.
*
* @param string $path
*
* @return bool
*/
protected function canImportFile($path) {
$parsed = parse_url($path);
if (
// file is elsewhere
isset($parsed['host']) ||
// file responds to queries (may change, or need to bypass cache)
isset($parsed['query'])
) {
return FALSE;
}
//return strlen($path) < PHP_MAXPATHLEN && @is_file($path) && is_readable($path);
}
/**
* Attempts to open file specified by $path for writing.
*
* @param string $path The path to the file
*
* @return resource Specifier for the target file
*
* @throws IOException
*/
protected function openFileForWriting($path) {
if (($handler = @fopen($path, 'w')) === FALSE) {
throw new IOException('The file "'.$path.'" could not be opened for writing. Check if PHP has enough permissions.');
}
return $handler;
}
/**
* Attempts to write $content to the file specified by $handler. $path is used for printing exceptions.
*
* @param resource $handler The resource to write to
* @param string $content The content to write
* @param string $path The path to the file (for exception printing only)
*
* @throws IOException
*/
protected function writeToFile($handler, $content, $path = '') {
if (($result = @fwrite($handler, $content)) === FALSE || ($result < strlen($content))) {
throw new IOException('The file "'.$path.'" could not be written to. Check your disk space and file permissions.');
}
}
}