ajax/xajaxCompress.php

   1 <?php
   2 /**
   3  * xajaxCompress.php :: function to compress Javascript
   4  *
   5  * xajax version 0.2.4
   6  * copyright (c) 2005 by Jared White & J. Max Wilson
   7  * http://www.xajaxproject.org
   8  *
   9  * xajax is an open source PHP class library for easily creating powerful
  10  * PHP-driven, web-based Ajax Applications. Using xajax, you can asynchronously
  11  * call PHP functions and update the content of your your webpage without
  12  * reloading the page.
  13  *
  14  * xajax is released under the terms of the LGPL license
  15  * http://www.gnu.org/copyleft/lesser.html#SEC3
  16  *
  17  * This library is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU Lesser General Public
  19  * License as published by the Free Software Foundation; either
  20  * version 2.1 of the License, or (at your option) any later version.
  21  *
  22  * This library is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  * Lesser General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU Lesser General Public
  28  * License along with this library; if not, write to the Free Software
  29  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  30  *
  31  * @package xajax
  32  * @version $Id$
  33  * @copyright Copyright (c) 2005-2006  by Jared White & J. Max Wilson
  34  * @license http://www.gnu.org/copyleft/lesser.html#SEC3 LGPL License
  35  */
  36
  37 /**
  38  * Compresses the Javascript code for more efficient delivery.
  39  * (used internally)
  40  *
  41  * @param string contains the Javascript code to compress
  42  */
  43 function xajaxCompressJavascript($sJS)
  44 {
  45         //remove windows cariage returns
  46         $sJS = str_replace("\r","",$sJS);
  47
  48         //array to store replaced literal strings
  49         $literal_strings = array();
  50
  51         //explode the string into lines
  52         $lines = explode("\n",$sJS);
  53         //loop through all the lines, building a new string at the same time as removing literal strings
  54         $clean = "";
  55         $inComment = false;
  56         $literal = "";
  57         $inQuote = false;
  58         $escaped = false;
  59         $quoteChar = "";
  60
  61         for($i=0;$i<count($lines);$i++)
  62         {
  63                 $line = $lines[$i];
  64                 $inNormalComment = false;
  65
  66                 //loop through line's characters and take out any literal strings, replace them with ___i___ where i is the index of this string
  67                 for($j=0;$j<strlen($line);$j++)
  68                 {
  69                         $c = substr($line,$j,1);
  70                         $d = substr($line,$j,2);
  71
  72                         //look for start of quote
  73                         if(!$inQuote && !$inComment)
  74                         {
  75                                 //is this character a quote or a comment
  76                                 if(($c=="\"" || $c=="'") && !$inComment && !$inNormalComment)
  77                                 {
  78                                         $inQuote = true;
  79                                         $inComment = false;
  80                                         $escaped = false;
  81                                         $quoteChar = $c;
  82                                         $literal = $c;
  83                                 }
  84                                 else if($d=="/*" && !$inNormalComment)
  85                                 {
  86                                         $inQuote = false;
  87                                         $inComment = true;
  88                                         $escaped = false;
  89                                         $quoteChar = $d;
  90                                         $literal = $d;
  91                                         $j++;
  92                                 }
  93                                 else if($d=="//") //ignore string markers that are found inside comments
  94                                 {
  95                                         $inNormalComment = true;
  96                                         $clean .= $c;
  97                                 }
  98                                 else
  99                                 {
 100                                         $clean .= $c;
 101                                 }
 102                         }
 103                         else //allready in a string so find end quote
 104                         {
 105                                 if($c == $quoteChar && !$escaped && !$inComment)
 106                                 {
 107                                         $inQuote = false;
 108                                         $literal .= $c;
 109
 110                                         //subsitute in a marker for the string
 111                                         $clean .= "___" . count($literal_strings) . "___";
 112
 113                                         //push the string onto our array
 114                                         array_push($literal_strings,$literal);
 115
 116                                 }
 117                                 else if($inComment && $d=="*/")
 118                                 {
 119                                         $inComment = false;
 120                                         $literal .= $d;
 121
 122                                         //subsitute in a marker for the string
 123                                         $clean .= "___" . count($literal_strings) . "___";
 124
 125                                         //push the string onto our array
 126                                         array_push($literal_strings,$literal);
 127
 128                                         $j++;
 129                                 }
 130                                 else if($c == "\\" && !$escaped)
 131                                         $escaped = true;
 132                                 else
 133                                         $escaped = false;
 134
 135                                 $literal .= $c;
 136                         }
 137                 }
 138                 if($inComment) $literal .= "\n";
 139                 $clean .= "\n";
 140         }
 141         //explode the clean string into lines again
 142         $lines = explode("\n",$clean);
 143
 144         //now process each line at a time
 145         for($i=0;$i<count($lines);$i++)
 146         {
 147                 $line = $lines[$i];
 148
 149                 //remove comments
 150                 $line = preg_replace("/\/\/(.*)/","",$line);
 151
 152                 //strip leading and trailing whitespace
 153                 $line = trim($line);
 154
 155                 //remove all whitespace with a single space
 156                 $line = preg_replace("/\s+/"," ",$line);
 157
 158                 //remove any whitespace that occurs after/before an operator
 159                 $line = preg_replace("/\s*([!\}\{;,&=\|\-\+\*\/\)\(:])\s*/","\\1",$line);
 160
 161                 $lines[$i] = $line;
 162         }
 163
 164         //implode the lines
 165         $sJS = implode("\n",$lines);
 166
 167         //make sure there is a max of 1 \n after each line
 168         $sJS = preg_replace("/[\n]+/","\n",$sJS);
 169
 170         //strip out line breaks that immediately follow a semi-colon
 171         $sJS = preg_replace("/;\n/",";",$sJS);
 172
 173         //curly brackets aren't on their own
 174         $sJS = preg_replace("/[\n]*\{[\n]*/","{",$sJS);
 175
 176         //finally loop through and replace all the literal strings:
 177         for($i=0;$i<count($literal_strings);$i++)
 178                 $sJS = str_replace("___".$i."___",$literal_strings[$i],$sJS);
 179
 180         return $sJS;
 181 }
 182 ?>