redcomani.org/weblocal/libs/xajax/xajax_js/xajaxCompress.php

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2018-10-16 20:00:54 +00:00
<?php
// xajaxCompressJavascript() compresses the javascript code for more efficient delivery
// used internally
// $sJS is a string containing the javascript code to compress
function xajaxCompressJavascript($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;
$quoteChar = "";
for($i=0;$i<count($lines);$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
for($i=0;$i<count($lines);$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:
for($i=0;$i<count($literal_strings);$i++)
$sJS = str_replace("___".$i."___",$literal_strings[$i],$sJS);
return $sJS;
}
?>