includes/JSMin.php

   1 <?php
   2 /**
   3  * jsmin.php - PHP implementation of Douglas Crockford's JSMin.
   4  *
   5  * This is pretty much a direct port of jsmin.c to PHP with just a few
   6  * PHP-specific performance tweaks. Also, whereas jsmin.c reads from stdin and
   7  * outputs to stdout, this library accepts a string as input and returns another
   8  * string as output.
   9  *
  10  * PHP 5 or higher is required.
  11  *
  12  * Permission is hereby granted to use this version of the library under the
  13  * same terms as jsmin.c, which has the following license:
  14  *
  15  * --
  16  * Copyright (c) 2002 Douglas Crockford  (www.crockford.com)
  17  *
  18  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  19  * this software and associated documentation files (the "Software"), to deal in
  20  * the Software without restriction, including without limitation the rights to
  21  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  22  * of the Software, and to permit persons to whom the Software is furnished to do
  23  * so, subject to the following conditions:
  24  *
  25  * The above copyright notice and this permission notice shall be included in all
  26  * copies or substantial portions of the Software.
  27  *
  28  * The Software shall be used for Good, not Evil.
  29  *
  30  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  31  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  32  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  33  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  34  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  35  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  36  * SOFTWARE.
  37  * --
  38  *
  39  * @package JSMin
  40  * @author Ryan Grove <ryan@wonko.com>
  41  * @copyright 2002 Douglas Crockford <douglas@crockford.com> (jsmin.c)
  42  * @copyright 2008 Ryan Grove <ryan@wonko.com> (PHP port)
  43  * @license http://opensource.org/licenses/mit-license.php MIT License
  44  * @version 1.1.1 (2008-03-02)
  45  * @link http://code.google.com/p/jsmin-php/
  46  */
  47
  48 class JSMin {
  49   const ORD_LF    = 10;
  50   const ORD_SPACE = 32;
  51
  52   protected $a           = '';
  53   protected $b           = '';
  54   protected $input       = '';
  55   protected $inputIndex  = 0;
  56   protected $inputLength = 0;
  57   protected $lookAhead   = null;
  58   protected $output      = '';
  59
  60   // -- Public Static Methods --------------------------------------------------
  61
  62   public static function minify($js) {
  63     $jsmin = new JSMin($js);
  64     return $jsmin->min();
  65   }
  66
  67   // -- Public Instance Methods ------------------------------------------------
  68
  69   public function __construct($input) {
  70     $this->input       = str_replace("\r\n", "\n", $input);
  71     $this->inputLength = strlen($this->input);
  72   }
  73
  74   // -- Protected Instance Methods ---------------------------------------------
  75
  76   protected function action($d) {
  77     switch($d) {
  78       case 1:
  79         $this->output .= $this->a;
  80
  81       case 2:
  82         $this->a = $this->b;
  83
  84         if ($this->a === "'" || $this->a === '"') {
  85           for (;;) {
  86             $this->output .= $this->a;
  87             $this->a       = $this->get();
  88
  89             if ($this->a === $this->b) {
  90               break;
  91             }
  92
  93             if (ord($this->a) <= self::ORD_LF) {
  94               throw new JSMinException('Unterminated string literal.');
  95             }
  96
  97             if ($this->a === '\\') {
  98               $this->output .= $this->a;
  99               $this->a       = $this->get();
 100             }
 101           }
 102         }
 103
 104       case 3:
 105         $this->b = $this->next();
 106
 107         if ($this->b === '/' && (
 108             $this->a === '(' || $this->a === ',' || $this->a === '=' ||
 109             $this->a === ':' || $this->a === '[' || $this->a === '!' ||
 110             $this->a === '&' || $this->a === '|' || $this->a === '?')) {
 111
 112           $this->output .= $this->a . $this->b;
 113
 114           for (;;) {
 115             $this->a = $this->get();
 116
 117             if ($this->a === '/') {
 118               break;
 119             } elseif ($this->a === '\\') {
 120               $this->output .= $this->a;
 121               $this->a       = $this->get();
 122             } elseif (ord($this->a) <= self::ORD_LF) {
 123               throw new JSMinException('Unterminated regular expression '.
 124                   'literal.');
 125             }
 126
 127             $this->output .= $this->a;
 128           }
 129
 130           $this->b = $this->next();
 131         }
 132     }
 133   }
 134
 135   protected function get() {
 136     $c = $this->lookAhead;
 137     $this->lookAhead = null;
 138
 139     if ($c === null) {
 140       if ($this->inputIndex < $this->inputLength) {
 141         $c = substr($this->input, $this->inputIndex, 1);
 142         $this->inputIndex += 1;
 143       } else {
 144         $c = null;
 145       }
 146     }
 147
 148     if ($c === "\r") {
 149       return "\n";
 150     }
 151
 152     if ($c === null || $c === "\n" || ord($c) >= self::ORD_SPACE) {
 153       return $c;
 154     }
 155
 156     return ' ';
 157   }
 158
 159   protected function isAlphaNum($c) {
 160     return ord($c) > 126 || $c === '\\' || preg_match('/^[\w\$]$/', $c) === 1;
 161   }
 162
 163   protected function min() {
 164     $this->a = "\n";
 165     $this->action(3);
 166
 167     while ($this->a !== null) {
 168       switch ($this->a) {
 169         case ' ':
 170           if ($this->isAlphaNum($this->b)) {
 171             $this->action(1);
 172           } else {
 173             $this->action(2);
 174           }
 175           break;
 176
 177         case "\n":
 178           switch ($this->b) {
 179             case '{':
 180             case '[':
 181             case '(':
 182             case '+':
 183             case '-':
 184               $this->action(1);
 185               break;
 186
 187             case ' ':
 188               $this->action(3);
 189               break;
 190
 191             default:
 192               if ($this->isAlphaNum($this->b)) {
 193                 $this->action(1);
 194               }
 195               else {
 196                 $this->action(2);
 197               }
 198           }
 199           break;
 200
 201         default:
 202           switch ($this->b) {
 203             case ' ':
 204               if ($this->isAlphaNum($this->a)) {
 205                 $this->action(1);
 206                 break;
 207               }
 208
 209               $this->action(3);
 210               break;
 211
 212             case "\n":
 213               switch ($this->a) {
 214                 case '}':
 215                 case ']':
 216                 case ')':
 217                 case '+':
 218                 case '-':
 219                 case '"':
 220                 case "'":
 221                   $this->action(1);
 222                   break;
 223
 224                 default:
 225                   if ($this->isAlphaNum($this->a)) {
 226                     $this->action(1);
 227                   }
 228                   else {
 229                     $this->action(3);
 230                   }
 231               }
 232               break;
 233
 234             default:
 235               $this->action(1);
 236               break;
 237           }
 238       }
 239     }
 240
 241     return $this->output;
 242   }
 243
 244   protected function next() {
 245     $c = $this->get();
 246
 247     if ($c === '/') {
 248       switch($this->peek()) {
 249         case '/':
 250           for (;;) {
 251             $c = $this->get();
 252
 253             if (ord($c) <= self::ORD_LF) {
 254               return $c;
 255             }
 256           }
 257
 258         case '*':
 259           $this->get();
 260
 261           for (;;) {
 262             switch($this->get()) {
 263               case '*':
 264                 if ($this->peek() === '/') {
 265                   $this->get();
 266                   return ' ';
 267                 }
 268                 break;
 269
 270               case null:
 271                 throw new JSMinException('Unterminated comment.');
 272             }
 273           }
 274
 275         default:
 276           return $c;
 277       }
 278     }
 279
 280     return $c;
 281   }
 282
 283   protected function peek() {
 284     $this->lookAhead = $this->get();
 285     return $this->lookAhead;
 286   }
 287 }
 288
 289 // -- Exceptions ---------------------------------------------------------------
 290 class JSMinException extends Exception {}
 291 ?>