<?php
/**
* CSS Minifier
*
* 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\FileImportException;
use PHPFusion\Minify\PathConverter\ConverterInterface;
use PHPFusion\Minify\PathConverter\Converter;
/**
* CSS minifier
*
* Please report bugs on https://github.com/matthiasmullie/minify/issues
*
* @package Minify
* @author Matthias Mullie <minify@mullie.eu>
* @author Tijs Verkoyen <minify@verkoyen.eu>
* @copyright Copyright (c) 2012, Matthias Mullie. All rights reserved
* @license MIT License
*/
class CSS extends Minify {
/**
* @var int maximum inport size in kB
*/
protected $maxImportSize = 5;
/**
* @var string[] valid import extensions
*/
protected $importExtensions = [
'gif' => 'data:image/gif',
'png' => 'data:image/png',
'jpe' => 'data:image/jpeg',
'jpg' => 'data:image/jpeg',
'jpeg' => 'data:image/jpeg',
'svg' => 'data:image/svg+xml',
'woff' => 'data:application/x-font-woff',
'tif' => 'image/tiff',
'tiff' => 'image/tiff',
'xbm' => 'image/x-xbitmap',
];
/**
* Set the maximum size if files to be imported.
*
* Files larger than this size (in kB) will not be imported into the CSS.
* Importing files into the CSS as data-uri will save you some connections,
* but we should only import relatively small decorative images so that our
* CSS file doesn't get too bulky.
*
* @param int $size Size in kB
*/
public function setMaxImportSize($size) {
$this->maxImportSize = $size;
}
/**
* Set the type of extensions to be imported into the CSS (to save network
* connections).
* Keys of the array should be the file extensions & respective values
* should be the data type.
*
* @param string[] $extensions Array of file extensions
*/
public function setImportExtensions(array $extensions) {
$this->importExtensions = $extensions;
}
/**
* Move any import statements to the top.
*
* @param string $content Nearly finished CSS content
*
* @return string
*/
protected function moveImportsToTop($content) {
if (preg_match_all('/(;?)(@import (?<url>url\()?(?P<quotes>["\']?).+?(?P=quotes)(?(url)\)));?/', $content, $matches)) {
// remove from content
foreach ($matches[0] as $import) {
$content = str_replace($import, '', $content);
}
// add to top
$content = implode(';', $matches[2]).';'.trim($content, ';');
}
return $content;
}
/**
* Combine CSS from import statements.
*
* @import's will be loaded and their content merged into the original file,
* to save HTTP requests.
*
* @param string $source The file to combine imports for
* @param string $content The CSS content to combine imports for
* @param string[] $parents Parent paths, for circular reference checks
*
* @return string
*
* @throws FileImportException
*/
protected function combineImports($source, $content, $parents) {
$importRegexes = [
// @import url(xxx)
'/
# import statement
@import
# whitespace
\s+
# open url()
url\(
# (optional) open path enclosure
(?P<quotes>["\']?)
# fetch path
(?P<path>.+?)
# (optional) close path enclosure
(?P=quotes)
# close url()
\)
# (optional) trailing whitespace
\s*
# (optional) media statement(s)
(?P<media>[^;]*)
# (optional) trailing whitespace
\s*
# (optional) closing semi-colon
;?
/ix',
// @import 'xxx'
'/
# import statement
@import
# whitespace
\s+
# open path enclosure
(?P<quotes>["\'])
# fetch path
(?P<path>.+?)
# close path enclosure
(?P=quotes)
# (optional) trailing whitespace
\s*
# (optional) media statement(s)
(?P<media>[^;]*)
# (optional) trailing whitespace
\s*
# (optional) closing semi-colon
;?
/ix',
];
// find all relative imports in css
$matches = [];
foreach ($importRegexes as $importRegex) {
if (preg_match_all($importRegex, $content, $regexMatches, PREG_SET_ORDER)) {
$matches = array_merge($matches, $regexMatches);
}
}
$search = [];
$replace = [];
// loop the matches
foreach ($matches as $match) {
// get the path for the file that will be imported
$importPath = dirname($source).'/'.$match['path'];
// only replace the import with the content if we can grab the
// content of the file
if (!$this->canImportByPath($match['path']) || !$this->canImportFile($importPath)) {
continue;
}
// check if current file was not imported previously in the same
// import chain.
if (in_array($importPath, $parents)) {
throw new FileImportException('Failed to import file "'.$importPath.'": circular reference detected.');
}
// grab referenced file & minify it (which may include importing
// yet other @import statements recursively)
$minifier = new static($importPath);
$minifier->setMaxImportSize($this->maxImportSize);
$minifier->setImportExtensions($this->importExtensions);
$importContent = $minifier->execute($source, $parents);
// check if this is only valid for certain media
if (!empty($match['media'])) {
$importContent = '@media '.$match['media'].'{'.$importContent.'}';
}
// add to replacement array
$search[] = $match[0];
$replace[] = $importContent;
}
// replace the import statements
return str_replace($search, $replace, $content);
}
/**
* Import files into the CSS, base64-ized.
*
* @url(image.jpg) images will be loaded and their content merged into the
* original file, to save HTTP requests.
*
* @param string $source The file to import files for
* @param string $content The CSS content to import files for
*
* @return string
*/
protected function importFiles($source, $content) {
$regex = '/url\((["\']?)(.+?)\\1\)/i';
if ($this->importExtensions && preg_match_all($regex, $content, $matches, PREG_SET_ORDER)) {
$search = [];
$replace = [];
// loop the matches
foreach ($matches as $match) {
$extension = substr(strrchr($match[2], '.'), 1);
if ($extension && !array_key_exists($extension, $this->importExtensions)) {
continue;
}
// get the path for the file that will be imported
$path = $match[2];
$path = dirname($source).'/'.$path;
// only replace the import with the content if we're able to get
// the content of the file, and it's relatively small
if ($this->canImportFile($path) && $this->canImportBySize($path)) {
// grab content && base64-ize
$importContent = $this->load($path);
$importContent = base64_encode($importContent);
// build replacement
$search[] = $match[0];
$replace[] = 'url('.$this->importExtensions[$extension].';base64,'.$importContent.')';
}
}
// replace the import statements
$content = str_replace($search, $replace, $content);
}
return $content;
}
/**
* Minify the data.
* Perform CSS optimizations.
*
* @param string[optional] $path Path to write the data to
* @param string[] $parents Parent paths, for circular reference checks
*
* @return string The minified data
*/
public function execute($path = NULL, $parents = []) {
$content = '';
// loop CSS data (raw data and files)
foreach ($this->data as $source => $css) {
/*
* Let's first take out strings & comments, since we can't just
* remove whitespace anywhere. If whitespace occurs inside a string,
* we should leave it alone. E.g.:
* p { content: "a test" }
*/
$this->extractStrings();
$this->stripComments();
$this->extractCalcs();
$css = $this->replace($css);
$css = $this->stripWhitespace($css);
$css = $this->shortenColors($css);
$css = $this->shortenZeroes($css);
$css = $this->shortenFontWeights($css);
$css = $this->stripEmptyTags($css);
// restore the string we've extracted earlier
$css = $this->restoreExtractedData($css);
$source = is_int($source) ? '' : $source;
$parents = $source ? array_merge($parents, [$source]) : $parents;
$css = $this->combineImports($source, $css, $parents);
$css = $this->importFiles($source, $css);
/*
* If we'll save to a new path, we'll have to fix the relative paths
* to be relative no longer to the source file, but to the new path.
* If we don't write to a file, fall back to same path so no
* conversion happens (because we still want it to go through most
* of the move code, which also addresses url() & @import syntax...)
*/
$converter = $this->getPathConverter($source, $path ?: $source);
$css = $this->move($converter, $css);
// combine css
$content .= $css;
}
$content = $this->moveImportsToTop($content);
return $content;
}
/**
* Moving a css file should update all relative urls.
* Relative references (e.g. ../images/image.gif) in a certain css file,
* will have to be updated when a file is being saved at another location
* (e.g. ../../images/image.gif, if the new CSS file is 1 folder deeper).
*
* @param ConverterInterface $converter Relative path converter
* @param string $content The CSS content to update relative urls for
*
* @return string
*/
protected function move(ConverterInterface $converter, $content) {
/*
* Relative path references will usually be enclosed by url(). @import
* is an exception, where url() is not necessary around the path (but is
* allowed).
* This *could* be 1 regular expression, where both regular expressions
* in this array are on different sides of a |. But we're using named
* patterns in both regexes, the same name on both regexes. This is only
* possible with a (?J) modifier, but that only works after a fairly
* recent PCRE version. That's why I'm doing 2 separate regular
* expressions & combining the matches after executing of both.
*/
$relativeRegexes = [
// url(xxx)
'/
# open url()
url\(
\s*
# open path enclosure
(?P<quotes>["\'])?
# fetch path
(?P<path>.+?)
# close path enclosure
(?(quotes)(?P=quotes))
\s*
# close url()
\)
/ix',
// @import "xxx"
'/
# import statement
@import
# whitespace
\s+
# we don\'t have to check for @import url(), because the
# condition above will already catch these
# open path enclosure
(?P<quotes>["\'])
# fetch path
(?P<path>.+?)
# close path enclosure
(?P=quotes)
/ix',
];
// find all relative urls in css
$matches = [];
foreach ($relativeRegexes as $relativeRegex) {
if (preg_match_all($relativeRegex, $content, $regexMatches, PREG_SET_ORDER)) {
$matches = array_merge($matches, $regexMatches);
}
}
$search = [];
$replace = [];
// loop all urls
foreach ($matches as $match) {
// determine if it's a url() or an @import match
$type = (strpos($match[0], '@import') === 0 ? 'import' : 'url');
$url = $match['path'];
if ($this->canImportByPath($url)) {
// attempting to interpret GET-params makes no sense, so let's discard them for awhile
$params = strrchr($url, '?');
$url = $params ? substr($url, 0, -strlen($params)) : $url;
// fix relative url
$url = $converter->convert($url);
// now that the path has been converted, re-apply GET-params
$url .= $params;
}
/*
* Urls with control characters above 0x7e should be quoted.
* According to Mozilla's parser, whitespace is only allowed at the
* end of unquoted urls.
* Urls with `)` (as could happen with data: uris) should also be
* quoted to avoid being confused for the url() closing parentheses.
* And urls with a # have also been reported to cause issues.
* Urls with quotes inside should also remain escaped.
*
* @see https://developer.mozilla.org/nl/docs/Web/CSS/url#The_url()_functional_notation
* @see https://hg.mozilla.org/mozilla-central/rev/14abca4e7378
* @see https://github.com/matthiasmullie/minify/issues/193
*/
$url = trim($url);
if (preg_match('/[\s\)\'"#\x{7f}-\x{9f}]/u', $url)) {
$url = $match['quotes'].$url.$match['quotes'];
}
// build replacement
$search[] = $match[0];
if ($type === 'url') {
$replace[] = 'url('.$url.')';
} else if ($type === 'import') {
$replace[] = '@import "'.$url.'"';
}
}
// replace urls
return str_replace($search, $replace, $content);
}
/**
* Shorthand hex color codes.
* #FF0000 -> #F00.
*
* @param string $content The CSS content to shorten the hex color codes for
*
* @return string
*/
protected function shortenColors($content) {
$content = preg_replace('/(?<=[: ])#([0-9a-z])\\1([0-9a-z])\\2([0-9a-z])\\3(?:([0-9a-z])\\4)?(?=[; }])/i', '#$1$2$3$4', $content);
// remove alpha channel if it's pointless...
$content = preg_replace('/(?<=[: ])#([0-9a-z]{6})ff?(?=[; }])/i', '#$1', $content);
$content = preg_replace('/(?<=[: ])#([0-9a-z]{3})f?(?=[; }])/i', '#$1', $content);
$colors = [
// we can shorten some even more by replacing them with their color name
'#F0FFFF' => 'azure',
'#F5F5DC' => 'beige',
'#A52A2A' => 'brown',
'#FF7F50' => 'coral',
'#FFD700' => 'gold',
'#808080' => 'gray',
'#008000' => 'green',
'#4B0082' => 'indigo',
'#FFFFF0' => 'ivory',
'#F0E68C' => 'khaki',
'#FAF0E6' => 'linen',
'#800000' => 'maroon',
'#000080' => 'navy',
'#808000' => 'olive',
'#CD853F' => 'peru',
'#FFC0CB' => 'pink',
'#DDA0DD' => 'plum',
'#800080' => 'purple',
'#F00' => 'red',
'#FA8072' => 'salmon',
'#A0522D' => 'sienna',
'#C0C0C0' => 'silver',
'#FFFAFA' => 'snow',
'#D2B48C' => 'tan',
'#FF6347' => 'tomato',
'#EE82EE' => 'violet',
'#F5DEB3' => 'wheat',
// or the other way around
'WHITE' => '#fff',
'BLACK' => '#000',
];
return preg_replace_callback(
'/(?<=[: ])('.implode('|', array_keys($colors)).')(?=[; }])/i',
function ($match) use ($colors) {
return $colors[strtoupper($match[0])];
},
$content
);
}
/**
* Shorten CSS font weights.
*
* @param string $content The CSS content to shorten the font weights for
*
* @return string
*/
protected function shortenFontWeights($content) {
$weights = [
'normal' => 400,
'bold' => 700,
];
$callback = function ($match) use ($weights) {
return $match[1].$weights[$match[2]];
};
return preg_replace_callback('/(font-weight\s*:\s*)('.implode('|', array_keys($weights)).')(?=[;}])/', $callback, $content);
}
/**
* Shorthand 0 values to plain 0, instead of e.g. -0em.
*
* @param string $content The CSS content to shorten the zero values for
*
* @return string
*/
protected function shortenZeroes($content) {
// we don't want to strip units in `calc()` expressions:
// `5px - 0px` is valid, but `5px - 0` is not
// `10px * 0` is valid (equates to 0), and so is `10 * 0px`, but
// `10 * 0` is invalid
// we've extracted calcs earlier, so we don't need to worry about this
// reusable bits of code throughout these regexes:
// before & after are used to make sure we don't match lose unintended
// 0-like values (e.g. in #000, or in http://url/1.0)
// units can be stripped from 0 values, or used to recognize non 0
// values (where wa may be able to strip a .0 suffix)
$before = '(?<=[:(, ])';
$after = '(?=[ ,);}])';
$units = '(em|ex|%|px|cm|mm|in|pt|pc|ch|rem|vh|vw|vmin|vmax|vm)';
// strip units after zeroes (0px -> 0)
// NOTE: it should be safe to remove all units for a 0 value, but in
// practice, Webkit (especially Safari) seems to stumble over at least
// 0%, potentially other units as well. Only stripping 'px' for now.
// @see https://github.com/matthiasmullie/minify/issues/60
$content = preg_replace('/'.$before.'(-?0*(\.0+)?)(?<=0)px'.$after.'/', '\\1', $content);
// strip 0-digits (.0 -> 0)
$content = preg_replace('/'.$before.'\.0+'.$units.'?'.$after.'/', '0\\1', $content);
// strip trailing 0: 50.10 -> 50.1, 50.10px -> 50.1px
$content = preg_replace('/'.$before.'(-?[0-9]+\.[0-9]+)0+'.$units.'?'.$after.'/', '\\1\\2', $content);
// strip trailing 0: 50.00 -> 50, 50.00px -> 50px
$content = preg_replace('/'.$before.'(-?[0-9]+)\.0+'.$units.'?'.$after.'/', '\\1\\2', $content);
// strip leading 0: 0.1 -> .1, 01.1 -> 1.1
$content = preg_replace('/'.$before.'(-?)0+([0-9]*\.[0-9]+)'.$units.'?'.$after.'/', '\\1\\2\\3', $content);
// strip negative zeroes (-0 -> 0) & truncate zeroes (00 -> 0)
$content = preg_replace('/'.$before.'-?0+'.$units.'?'.$after.'/', '0\\1', $content);
// IE doesn't seem to understand a unitless flex-basis value (correct -
// it goes against the spec), so let's add it in again (make it `%`,
// which is only 1 char: 0%, 0px, 0 anything, it's all just the same)
// @see https://developer.mozilla.org/nl/docs/Web/CSS/flex
$content = preg_replace('/flex:([0-9]+\s[0-9]+\s)0([;\}])/', 'flex:${1}0%${2}', $content);
$content = preg_replace('/flex-basis:0([;\}])/', 'flex-basis:0%${1}', $content);
return $content;
}
/**
* Strip empty tags from source code.
*
* @param string $content
*
* @return string
*/
protected function stripEmptyTags($content) {
$content = preg_replace('/(?<=^)[^\{\};]+\{\s*\}/', '', $content);
$content = preg_replace('/(?<=(\}|;))[^\{\};]+\{\s*\}/', '', $content);
return $content;
}
/**
* Strip comments from source code.
*/
protected function stripComments() {
// PHP only supports $this inside anonymous functions since 5.4
$minifier = $this;
$callback = function ($match) use ($minifier) {
$count = count($minifier->extracted);
$placeholder = '/*'.$count.'*/';
$minifier->extracted[$placeholder] = $match[0];
return $placeholder;
};
$this->registerPattern('/\n?\/\*(!|.*?@license|.*?@preserve).*?\*\/\n?/s', $callback);
$this->registerPattern('/\/\*.*?\*\//s', '');
}
/**
* Strip whitespace.
*
* @param string $content The CSS content to strip the whitespace for
*
* @return string
*/
protected function stripWhitespace($content) {
// remove leading & trailing whitespace
$content = preg_replace('/^\s*/m', '', $content);
$content = preg_replace('/\s*$/m', '', $content);
// replace newlines with a single space
$content = preg_replace('/\s+/', ' ', $content);
// remove whitespace around meta characters
// inspired by stackoverflow.com/questions/15195750/minify-compress-css-with-regex
$content = preg_replace('/\s*([\*$~^|]?+=|[{};,>~]|!important\b)\s*/', '$1', $content);
$content = preg_replace('/([\[(:>\+])\s+/', '$1', $content);
$content = preg_replace('/\s+([\]\)>\+])/', '$1', $content);
$content = preg_replace('/\s+(:)(?![^\}]*\{)/', '$1', $content);
// whitespace around + and - can only be stripped inside some pseudo-
// classes, like `:nth-child(3+2n)`
// not in things like `calc(3px + 2px)`, shorthands like `3px -2px`, or
// selectors like `div.weird- p`
$pseudos = ['nth-child', 'nth-last-child', 'nth-last-of-type', 'nth-of-type'];
$content = preg_replace('/:('.implode('|', $pseudos).')\(\s*([+-]?)\s*(.+?)\s*([+-]?)\s*(.*?)\s*\)/', ':$1($2$3$4$5)', $content);
// remove semicolon/whitespace followed by closing bracket
$content = str_replace(';}', '}', $content);
return trim($content);
}
/**
* Replace all `calc()` occurrences.
*/
protected function extractCalcs() {
// PHP only supports $this inside anonymous functions since 5.4
$minifier = $this;
$callback = function ($match) use ($minifier) {
$length = strlen($match[1]);
$expr = '';
$opened = 0;
for ($i = 0; $i < $length; $i++) {
$char = $match[1][$i];
$expr .= $char;
if ($char === '(') {
$opened++;
} else if ($char === ')' && --$opened === 0) {
break;
}
}
$rest = str_replace($expr, '', $match[1]);
$expr = trim(substr($expr, 1, -1));
$count = count($minifier->extracted);
$placeholder = 'calc('.$count.')';
$minifier->extracted[$placeholder] = 'calc('.$expr.')';
return $placeholder.$rest;
};
$this->registerPattern('/calc(\(.+?)(?=$|;|}|calc\()/', $callback);
$this->registerPattern('/calc(\(.+?)(?=$|;|}|calc\()/m', $callback);
}
/**
* Check if file is small enough to be imported.
*
* @param string $path The path to the file
*
* @return bool
*/
protected function canImportBySize($path) {
return ($size = @filesize($path)) && $size <= $this->maxImportSize * 1024;
}
/**
* Check if file a file can be imported, going by the path.
*
* @param string $path
*
* @return bool
*/
protected function canImportByPath($path) {
return preg_match('/^(data:|https?:|\\/)/', $path) === 0;
}
/**
* Return a converter to update relative paths to be relative to the new
* destination.
*
* @param string $source
* @param string $target
*
* @return ConverterInterface
*/
protected function getPathConverter($source, $target) {
return new Converter($source, $target);
}
}