source: trunk/workflow/inc/report/xajax/xajaxCompress.php @ 7655

<?php
/**
 * xajaxCompress.php :: function to compress Javascript
 *
 * xajax version 0.2.4
 * copyright (c) 2005 by Jared White & J. Max Wilson
 * http://www.xajaxproject.org
 *
 * xajax is an open source PHP class library for easily creating powerful
 * PHP-driven, web-based Ajax Applications. Using xajax, you can asynchronously
 * call PHP functions and update the content of your your webpage without
 * reloading the page.
 *
 * xajax is released under the terms of the LGPL license
 * http://www.gnu.org/copyleft/lesser.html#SEC3
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * @package xajax
 * @version $Id$
 * @copyright Copyright (c) 2005-2006  by Jared White & J. Max Wilson
 * @license http://www.gnu.org/copyleft/lesser.html#SEC3 LGPL License
 */

/**
 * Compresses the Javascript code for more efficient delivery.
 * (used internally)
 * 
 * @param string contains the Javascript code to compress
 */
function xajaxCompressJavascript($sJS)
{
        //remove windows cariage returns
        $sJS = str_replace("\r","",$sJS);
        
        //array to store replaced literal strings
        $literal_strings = array();
        
        //explode the string into lines
        $lines = explode("\n",$sJS);
        //loop through all the lines, building a new string at the same time as removing literal strings
        $clean = "";
        $inComment = false;
        $literal = "";
        $inQuote = false;
        $escaped = false;
        $quoteChar = "";
    $lines_count = count($lines);

        for($i=0;$i<$lines_count;++$i)
        {
                $line = $lines[$i];
                $inNormalComment = false;
        
                //loop through line's characters and take out any literal strings, replace them with ___i___ where i is the index of this string
                for($j=0;$j<strlen($line);++$j)
                {
                        $c = substr($line,$j,1);
                        $d = substr($line,$j,2);
        
                        //look for start of quote
                        if(!$inQuote && !$inComment)
                        {
                                //is this character a quote or a comment
                                if(($c=="\"" || $c=="'") && !$inComment && !$inNormalComment)
                                {
                                        $inQuote = true;
                                        $inComment = false;
                                        $escaped = false;
                                        $quoteChar = $c;
                                        $literal = $c;
                                }
                                else if($d=="/*" && !$inNormalComment)
                                {
                                        $inQuote = false;
                                        $inComment = true;
                                        $escaped = false;
                                        $quoteChar = $d;
                                        $literal = $d;  
                                        ++$j;
                                }
                                else if($d=="//") //ignore string markers that are found inside comments
                                {
                                        $inNormalComment = true;
                                        $clean .= $c;
                                }
                                else
                                {
                                        $clean .= $c;
                                }
                        }
                        else //allready in a string so find end quote
                        {
                                if($c == $quoteChar && !$escaped && !$inComment)
                                {
                                        $inQuote = false;
                                        $literal .= $c;
        
                                        //subsitute in a marker for the string
                                        $clean .= "___" . count($literal_strings) . "___";
        
                                        //push the string onto our array
                                        array_push($literal_strings,$literal);
        
                                }
                                else if($inComment && $d=="*/")
                                {
                                        $inComment = false;
                                        $literal .= $d;
        
                                        //subsitute in a marker for the string
                                        $clean .= "___" . count($literal_strings) . "___";
        
                                        //push the string onto our array
                                        array_push($literal_strings,$literal);
        
                                        ++$j;
                                }
                                else if($c == "\\" && !$escaped)
                                        $escaped = true;
                                else
                                        $escaped = false;
        
                                $literal .= $c;
                        }
                }
                if($inComment) $literal .= "\n";
                $clean .= "\n";
        }
        //explode the clean string into lines again
        $lines = explode("\n",$clean);
        
        //now process each line at a time
    $lines_count = count($lines);
        for($i=0;$i<$lines_count;++$i)
        {
                $line = $lines[$i];
        
                //remove comments
                $line = preg_replace("/\/\/(.*)/","",$line);
        
                //strip leading and trailing whitespace
                $line = trim($line);
        
                //remove all whitespace with a single space
                $line = preg_replace("/\s+/"," ",$line);
        
                //remove any whitespace that occurs after/before an operator
                $line = preg_replace("/\s*([!\}\{;,&=\|\-\+\*\/\)\(:])\s*/","\\1",$line);
        
                $lines[$i] = $line;
        }
        
        //implode the lines
        $sJS = implode("\n",$lines);
        
        //make sure there is a max of 1 \n after each line
        $sJS = preg_replace("/[\n]+/","\n",$sJS);
        
        //strip out line breaks that immediately follow a semi-colon
        $sJS = preg_replace("/;\n/",";",$sJS);
        
        //curly brackets aren't on their own
        $sJS = preg_replace("/[\n]*\{[\n]*/","{",$sJS);
        
        //finally loop through and replace all the literal strings:
    $literal_strings_count = count($literal_strings);
        for($i=0;$i<$literal_strings_count;++$i)
                $sJS = str_replace("___".$i."___",$literal_strings[$i],$sJS);
        
        return $sJS;
}
?>