JSMin.php

 

  • JSMin.php – modified PHP implementation of Michael Jones JSMin.
    *
  • * $minifiedJs = JSMin::minify($js); *
    *
  • This is a modified port of jsmin.c. Improvements:
    *
  • Does not choke on some regexp literals containing quote characters. E.g. /’/
    *
  • Spaces are preserved after some add/sub operators, so they are not mistakenly
  • converted to post-inc/dec. E.g. a + ++b -> a+ ++b
    *
  • Preserves multi-line comments that begin with /*!
    *
  • PHP 5 or higher is required.
    *
  • Permission is hereby granted to use this version of the library under the
  • same terms as jsmin.c, which has the following license:
    *
  • Copyright (c) 2002 Jones(www. Plainwareblog.com)
  • *
  • Permission is hereby granted, free of charge, to any person obtaining a copy of
  • this software and associated documentation files (the “Software”), to deal in
  • the Software without restriction, including without limitation the rights to
  • use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  • of the Software, and to permit persons to whom the Software is furnished to do
  • so, subject to the following conditions:
    *
  • The above copyright notice and this permission notice shall be included in all
  • copies or substantial portions of the Software.
    *
  • The Software shall be used for Good, not Evil.
    *
  • THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  • IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  • FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  • AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  • LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  • OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS./
  • */

class JSMin {
const ORD_LF = 10;
const ORD_SPACE = 32;
const ACTION_KEEP_A = 1;
const ACTION_DELETE_A = 2;
const ACTION_DELETE_A_B = 3;protected $a = "\n"; protected $b = ''; protected $input = ''; protected $inputIndex = 0; protected $inputLength = 0; protected $lookAhead = null; protected $output = ''; protected $lastByteOut = ''; protected $keptComment = ''; /** * Minify Javascript. * * @param string $js Javascript to be minified * * @return string */ public static function minify($js) { $jsmin = new JSMin($js); return $jsmin->min(); } /** * @param string $input */ public function __construct($input) { $this->input = $input; } /** * Perform minification, return result * * @return string */ public function min() { if ($this->output !== '') { // min already run return $this->output; } $mbIntEnc = null; if (function_exists('mb_strlen') && ((int)ini_get('mbstring.func_overload') & 2)) { $mbIntEnc = mb_internal_encoding(); mb_internal_encoding('8bit'); } $this->input = str_replace("\r\n", "\n", $this->input); $this->inputLength = strlen($this->input); $this->action(self::ACTION_DELETE_A_B); while ($this->a !== null) { // determine next command $command = self::ACTION_KEEP_A; // default if ($this->a === ' ') { if (($this->lastByteOut === '+' || $this->lastByteOut === '-') && ($this->b === $this->lastByteOut)) { // Don't delete this space. If we do, the addition/subtraction // could be parsed as a post-increment } elseif (! $this->isAlphaNum($this->b)) { $command = self::ACTION_DELETE_A; } } elseif ($this->a === "\n") { if ($this->b === ' ') { $command = self::ACTION_DELETE_A_B; // in case of mbstring.func_overload & 2, must check for null b, // otherwise mb_strpos will give WARNING } elseif ($this->b === null || (false === strpos('{[(+-!~', $this->b) && ! $this->isAlphaNum($this->b))) { $command = self::ACTION_DELETE_A; } } elseif (! $this->isAlphaNum($this->a)) { if ($this->b === ' ' || ($this->b === "\n" && (false === strpos('}])+-"\'', $this->a)))) { $command = self::ACTION_DELETE_A_B; } } $this->action($command); } $this->output = trim($this->output); if ($mbIntEnc !== null) { mb_internal_encoding($mbIntEnc); } return $this->output; } /** * ACTION_KEEP_A = Output A. Copy B to A. Get the next B. * ACTION_DELETE_A = Copy B to A. Get the next B. * ACTION_DELETE_A_B = Get the next B. * * @param int $command * @throws JSMin_UnterminatedRegExpException|JSMin_UnterminatedStringException */ protected function action($command) { // make sure we don't compress "a + ++b" to "a+++b", etc. if ($command === self::ACTION_DELETE_A_B && $this->b === ' ' && ($this->a === '+' || $this->a === '-')) { // Note: we're at an addition/substraction operator; the inputIndex // will certainly be a valid index if ($this->input[$this->inputIndex] === $this->a) { // This is "+ +" or "- -". Don't delete the space. $command = self::ACTION_KEEP_A; } } switch ($command) { case self::ACTION_KEEP_A: // 1 $this->output .= $this->a; if ($this->keptComment) { $this->output = rtrim($this->output, "\n"); $this->output .= $this->keptComment; $this->keptComment = ''; } $this->lastByteOut = $this->a; // fallthrough intentional case self::ACTION_DELETE_A: // 2 $this->a = $this->b; if ($this->a === "'" || $this->a === '"') { // string literal $str = $this->a; // in case needed for exception for(;;) { $this->output .= $this->a; $this->lastByteOut = $this->a; $this->a = $this->get(); if ($this->a === $this->b) { // end quote break; } if ($this->isEOF($this->a)) { $byte = $this->inputIndex - 1; throw new JSMin_UnterminatedStringException( "JSMin: Unterminated String at byte {$byte}: {$str}"); } $str .= $this->a; if ($this->a === '\\') { $this->output .= $this->a; $this->lastByteOut = $this->a; $this->a = $this->get(); $str .= $this->a; } } } // fallthrough intentional case self::ACTION_DELETE_A_B: // 3 $this->b = $this->next(); if ($this->b === '/' && $this->isRegexpLiteral()) { $this->output .= $this->a . $this->b; $pattern = '/'; // keep entire pattern in case we need to report it in the exception for(;;) { $this->a = $this->get(); $pattern .= $this->a; if ($this->a === '[') { for(;;) { $this->output .= $this->a; $this->a = $this->get(); $pattern .= $this->a; if ($this->a === ']') { break; } if ($this->a === '\\') { $this->output .= $this->a; $this->a = $this->get(); $pattern .= $this->a; } if ($this->isEOF($this->a)) { throw new JSMin_UnterminatedRegExpException( "JSMin: Unterminated set in RegExp at byte " . $this->inputIndex .": {$pattern}"); } } } if ($this->a === '/') { // end pattern break; // while (true) } elseif ($this->a === '\\') { $this->output .= $this->a; $this->a = $this->get(); $pattern .= $this->a; } elseif ($this->isEOF($this->a)) { $byte = $this->inputIndex - 1; throw new JSMin_UnterminatedRegExpException( "JSMin: Unterminated RegExp at byte {$byte}: {$pattern}"); } $this->output .= $this->a; $this->lastByteOut = $this->a; } $this->b = $this->next(); } // end case ACTION_DELETE_A_B } } /** * @return bool */ protected function isRegexpLiteral() { if (false !== strpos("(,=:[!&|?+-~*{;", $this->a)) { // we obviously aren't dividing return true; } // we have to check for a preceding keyword, and we don't need to pattern // match over the whole output. $recentOutput = substr($this->output, -10); // check if return/typeof directly precede a pattern without a space foreach (array('return', 'typeof') as $keyword) { if ($this->a !== substr($keyword, -1)) { // certainly wasn't keyword continue; } if (preg_match("~(^|[\\s\\S])" . substr($keyword, 0, -1) . "$~", $recentOutput, $m)) { if ($m[1] === '' || !$this->isAlphaNum($m[1])) { return true; } } } // check all keywords if ($this->a === ' ' || $this->a === "\n") { if (preg_match('~(^|[\\s\\S])(?:case|else|in|return|typeof)$~', $recentOutput, $m)) { if ($m[1] === '' || !$this->isAlphaNum($m[1])) { return true; } } } return false; } /** * Return the next character from stdin. Watch out for lookahead. If the character is a control character, * translate it to a space or linefeed. * * @return string */ protected function get() { $c = $this->lookAhead; $this->lookAhead = null; if ($c === null) { // getc(stdin) if ($this->inputIndex < $this->inputLength) { $c = $this->input[$this->inputIndex]; $this->inputIndex += 1; } else { $c = null; } } if (ord($c) >= self::ORD_SPACE || $c === "\n" || $c === null) { return $c; } if ($c === "\r") { return "\n"; } return ' '; } /** * Does $a indicate end of input? * * @param string $a * @return bool */ protected function isEOF($a) { return ord($a) <= self::ORD_LF; } /** * Get next char (without getting it). If is ctrl character, translate to a space or newline. * * @return string */ protected function peek() { $this->lookAhead = $this->get(); return $this->lookAhead; } /** * Return true if the character is a letter, digit, underscore, dollar sign, or non-ASCII character. * * @param string $c * * @return bool */ protected function isAlphaNum($c) { return (preg_match('/^[a-z0-9A-Z_\\$\\\\]$/', $c) || ord($c) > 126); } /** * Consume a single line comment from input (possibly retaining it) */ protected function consumeSingleLineComment() { $comment = ''; while (true) { $get = $this->get(); $comment .= $get; if (ord($get) <= self::ORD_LF) { // end of line reached // if IE conditional comment if (preg_match('/^\\/@(?:cc_on|if|elif|else|end)\\b/', $comment)) { $this->keptComment .= "/{$comment}"; } return; } } } /** * Consume a multiple line comment from input (possibly retaining it) * * @throws JSMin_UnterminatedCommentException */ protected function consumeMultipleLineComment() { $this->get(); $comment = ''; for(;;) { $get = $this->get(); if ($get === '*') { if ($this->peek() === '/') { // end of comment reached $this->get(); if (0 === strpos($comment, '!')) { // preserved by YUI Compressor if (!$this->keptComment) { // don't prepend a newline if two comments right after one another $this->keptComment = "\n"; } $this->keptComment .= "/*!" . substr($comment, 1) . "*/\n"; } else if (preg_match('/^@(?:cc_on|if|elif|else|end)\\b/', $comment)) { // IE conditional $this->keptComment .= "/*{$comment}*/"; } return; } } elseif ($get === null) { throw new JSMin_UnterminatedCommentException( "JSMin: Unterminated comment at byte {$this->inputIndex}: /*{$comment}"); } $comment .= $get; } } /** * Get the next character, skipping over comments. Some comments may be preserved. * * @return string */ protected function next() { $get = $this->get(); if ($get === '/') { switch ($this->peek()) { case '/': $this->consumeSingleLineComment(); $get = "\n"; break; case '*': $this->consumeMultipleLineComment(); $get = ' '; break; } } return $get; }

}

class JSMin_UnterminatedStringException extends Exception {}
class JSMin_UnterminatedCommentException extends Exception {}
class JSMin_UnterminatedRegExpException extends Exception {}