<?php
/**
* Class Minify_CommentPreserver
* @package Minify
*/
/**
* Process a string in pieces preserving C-style comments that begin with "/*!"
*
* @package Minify
* @author Stephen Clay <steve@mrclay.org>
*/
class Minify_CommentPreserver
{
/**
* String to be prepended to each preserved comment
*
* @var string
*/
public static $prepend = "\n";
/**
* String to be appended to each preserved comment
*
* @var string
*/
public static $append = "\n";
/**
* Process a string outside of C-style comments that begin with "/*!"
*
* On each non-empty string outside these comments, the given processor
* function will be called. The comments will be surrounded by
* Minify_CommentPreserver::$preprend and Minify_CommentPreserver::$append.
*
* @param string $content
* @param callback $processor function
* @param array $args array of extra arguments to pass to the processor
* function (default = array())
* @return string
*/
public static function process($content, $processor, $args = array())
{
$ret = '';
while (true) {
list($beforeComment, $comment, $afterComment) = self::_nextComment($content);
if ('' !== $beforeComment) {
$callArgs = $args;
array_unshift($callArgs, $beforeComment);
$ret .= call_user_func_array($processor, $callArgs);
}
if (false === $comment) {
break;
}
$ret .= $comment;
$content = $afterComment;
}
return $ret;
}
/**
* Extract comments that YUI Compressor preserves.
*
* @param string $in input
*
* @return array 3 elements are returned. If a YUI comment is found, the
* 2nd element is the comment and the 1st and 3rd are the surrounding
* strings. If no comment is found, the entire string is returned as the
* 1st element and the other two are false.
*/
private static function _nextComment($in)
{
if (false === ($start = strpos($in, '/*!')) || false === ($end = strpos($in, '*/', $start + 3))) {
return array($in, false, false);
}
$beforeComment = substr($in, 0, $start);
$comment = self::$prepend . '/*!' . substr($in, $start + 3, $end - $start - 1) . self::$append;
$endChars = (strlen($in) - $end - 2);
$afterComment = (0 === $endChars) ? '' : substr($in, -$endChars);
return array($beforeComment, $comment, $afterComment);
}
}
