root/dev/mods/xajax/xajax_core/xajaxCompress.inc.php @ 259

<?php

/*
        Function: xajaxCompressFile
        
        <xajax> will call this function internally to compress the javascript code for 
        more efficient delivery.
        
        $sFile - (stirng):  The file to be compressed.
*/
function xajaxCompressFile($sFile)
{
        //remove windows cariage returns
        $sFile = str_replace("\r",'',$sFile);
        
        //array to store replaced literal strings
        $literal_strings = array();
        
        //explode the string into lines
        $lines = explode("\n",$sFile);
        //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 = '';
        
        $iLen = count($lines);
        for($i=0; $i<$iLen; ++$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
                $jLen = strlen($line);
                for($j=0; $j<$jLen; ++$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
                                {
                                        $inNormalComment = true;
                                }
                                else
                                {
                                        if (!$inNormalComment)
                                                $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 .= $d;
                                        ++$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
        $iLen = count($lines);
        for($i=0; $i<$iLen; ++$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
        $sFile = implode("\n",$lines);
        
        //make sure there is a max of 1 \n after each line
        $sFile = preg_replace("/[\n]+/","\n",$sFile);
        
        //strip out line breaks that immediately follow a semi-colon
        $sFile = preg_replace("/;\n/",";",$sFile);
        
        //curly brackets aren't on their own
        $sFile = preg_replace("/[\n]*\{[\n]*/","{",$sFile);
        
        //finally loop through and replace all the literal strings:
        $iLen = count($literal_strings);
        for($i=0; $i<$iLen; ++$i)
                $sFile = str_replace('___'.$i.'___',$literal_strings[$i],$sFile);
        
        return $sFile;
}