tags var $block_elements = 'div|blockquote|pre|code|h\d|script|ol|un'; // Elements that should not have

and
tags within them. var $skip_elements = 'pre|ol|ul'; // Tags we want the parser to completely ignore when splitting the string. var $ignore_elements = 'a|b|i|em|strong|span|img|li'; /** * Main Processing Function * */ function convert($str) { if ($str == '') { return ''; } $str = ' '.$str.' '; // Standardize Newlines to make matching easier $str = preg_replace("/(\r\n|\r)/", "\n", $str); /* * Reduce line breaks * * If there are more than two consecutive line * breaks we'll compress them down to a maximum * of two since there's no benefit to more. * */ $str = preg_replace("/\n\n+/", "\n\n", $str); /* * Convert quotes within tags to tempoarary marker * * We don't want quotes converted within * tags so we'll temporarily convert them to * {{{DQ}}} and {{{SQ}}} * */ if (preg_match_all("#\<.+?>#si", $str, $matches)) { for ($i = 0; $i < count($matches['0']); $i++) { $str = str_replace($matches['0'][$i], str_replace(array("'",'"'), array('{{{SQ}}}', '{{{DQ}}}'), $matches['0'][$i]), $str); } } /* * Convert "ignore" tags to tempoarary marker * * The parser splits out the string at every tag * it encounters. Certain inline tags, like image * tags, links, span tags, etc. will be adversely * affected if they are split out so we'll convert * the opening < temporarily to: {{{tag}}} * */ $str = preg_replace("#<(/*)(".$this->ignore_elements.")#i", "{{{tag}}}\\1\\2", $str); /* * Split the string at every tag * * This creates an array with this prototype: * * [array] * { * [0] = * [1] = Content contained between the tags * [2] = * Etc... * } * */ $chunks = preg_split('/(<(?:[^<>]+(?:"[^"]*"|\'[^\']*\')?)+>)/', $str, -1, PREG_SPLIT_DELIM_CAPTURE|PREG_SPLIT_NO_EMPTY); /* * Build our finalized string * * We'll cycle through the array, skipping tags, * and processing the contained text * */ $str = ''; $process = TRUE; foreach ($chunks as $chunk) { /* * Are we dealing with a tag? * * If so, we'll skip the processing for this cycle. * Well also set the "process" flag which allows us * to skip

 tags and a few other things.
			 *
			 */			
			if (preg_match("#<(/*)(".$this->block_elements.").*?\>#", $chunk, $match)) 
			{
				if (preg_match("#".$this->skip_elements."#", $match['2']))
				{
					$process =  ($match['1'] == '/') ? TRUE : FALSE;		
				}
		
				$str .= $chunk;
				continue;
			}
		
			if ($process == FALSE)
			{
				$str .= $chunk;
				continue;
			}
			
			//  Convert Newlines into 
 and 
 tags
			$str .= $this->format_newlines($chunk);
		}

		// Convert Quotes and other characters
		$str = $this->format_characters($str);

		//  We'll swap our temporary markers back and do some clean up.
		$str = preg_replace('#(
\n*
)#', '', $str);
		$str = preg_replace('#()
#', "\\1", $str);
		
		$str = str_replace(
							array('
', '
', '{{{tag}}}', '{{{DQ}}}', '{{{SQ}}}'), 
							array('
', '
', '<', '"', "'"), 
							$str
							);
		
		return trim($str);
	}
	
	// --------------------------------------------------------------------

	/**
	 * Format Characters
	 *
	 * This function mainly converts double and single quotes
	 * to entities, but since these are directional, it does
	 * it based on some rules.  It also converts em-dashes
	 * and a couple other things.
	 */
	function format_characters($str)
	{	
		$table = array(
						' "'		=> " “",
						'" '		=> "” ",
						" '"		=> " ‘",
						"' "		=> "’ ",
						
						'>"'		=> ">“",
						'"<'		=> "”<",
						">'"		=> ">‘",
						"'<"		=> "’<",

						"\"."		=> "”.",
						"\","		=> "”,",
						"\";"		=> "”;",
						"\":"		=> "”:",
						"\"!"		=> "”!",
						"\"?"		=> "”?",
						
						".  "		=> ".  ",
						"?  "		=> "?  ",
						"!  "		=> "!  ",
						":  "		=> ":  ",
					);

		// These deal with quotes within quotes, like:  "'hi here'"
		$start = 0;
		$space = array("\n", "\t", " ");
		
		while(TRUE)
		{
			$current = strpos(substr($str, $start), "\"'");
			
			if ($current === FALSE) break;
			
			$one_before = substr($str, $start+$current-1, 1);
			$one_after = substr($str, $start+$current+2, 1);
			
			if ( ! in_array($one_after, $space) && $one_after != "<")
			{
				$str = str_replace(	$one_before."\"'".$one_after,
									$one_before."“‘".$one_after,
									$str);
			}
			elseif ( ! in_array($one_before, $space) && (in_array($one_after, $space) OR $one_after == '<'))
			{
				$str = str_replace(	$one_before."\"'".$one_after,
									$one_before."”’".$one_after,
									$str);
			}
			
			$start = $start+$current+2;
		}
		
		$start = 0;
		
		while(TRUE)
		{
			$current = strpos(substr($str, $start), "'\"");
			
			if ($current === FALSE) break;
			
			$one_before = substr($str, $start+$current-1, 1);
			$one_after = substr($str, $start+$current+2, 1);
			
			if ( in_array($one_before, $space) && ! in_array($one_after, $space) && $one_after != "<")
			{
				$str = str_replace(	$one_before."'\"".$one_after,
									$one_before."‘“".$one_after,
									$str);
			}
			elseif ( ! in_array($one_before, $space) && $one_before != ">")
			{
				$str = str_replace(	$one_before."'\"".$one_after,
									$one_before."’”".$one_after,
									$str);
			}
			
			$start = $start+$current+2;
		}
		
		// Are there quotes within a word, as in:  ("something")
		if (preg_match_all("/(.)\"(\S+?)\"(.)/", $str, $matches))
		{
			for ($i=0, $s=sizeof($matches['0']); $i < $s; ++$i)
			{
				if ( ! in_array($matches['1'][$i], $space) && ! in_array($matches['3'][$i], $space))
				{
					$str = str_replace(	$matches['0'][$i],
										$matches['1'][$i]."“".$matches['2'][$i]."”".$matches['3'][$i],
										$str);
				}
			}
		}
		
		if (preg_match_all("/(.)\'(\S+?)\'(.)/", $str, $matches))
		{
			for ($i=0, $s=sizeof($matches['0']); $i < $s; ++$i)
			{
				if ( ! in_array($matches['1'][$i], $space) && ! in_array($matches['3'][$i], $space))
				{
					$str = str_replace(	$matches['0'][$i],
										$matches['1'][$i]."‘".$matches['2'][$i]."’".$matches['3'][$i],
										$str);
				}
			}
		}
		
		// How about one apostrophe, as in Rick's
		$start = 0;
		
		while(TRUE)
		{
			$current = strpos(substr($str, $start), "'");
			
			if ($current === FALSE) break;
			
			$one_before = substr($str, $start+$current-1, 1);
			$one_after = substr($str, $start+$current+1, 1);
			
			if ( ! in_array($one_before, $space) && ! in_array($one_after, $space))
			{
				$str = str_replace(	$one_before."'".$one_after,
									$one_before."’".$one_after,
									$str);
			}
			
			$start = $start+$current+2;
		}

		// Em-dashes
		$start = 0;
		while(TRUE)
		{
			$current = strpos(substr($str, $start), "--");
			
			if ($current === FALSE) break;
			
			$one_before = substr($str, $start+$current-1, 1);
			$one_after = substr($str, $start+$current+2, 1);
			$two_before = substr($str, $start+$current-2, 1);
			$two_after = substr($str, $start+$current+3, 1);
			
			if (( ! in_array($one_before, $space) && ! in_array($one_after, $space))
				OR
				( ! in_array($two_before, $space) && ! in_array($two_after, $space) && $one_before == ' ' && $one_after == ' ')
				)
			{
				$str = str_replace(	$two_before.$one_before."--".$one_after.$two_after,
									$two_before.trim($one_before)."—".trim($one_after).$two_after,
									$str);
			}
			
			$start = $start+$current+2;
		}
		
		// Ellipsis
		$str = preg_replace("#(\w)\.\.\.(\s|
|
)#", "\\1…\\2", $str); 
		$str = preg_replace("#(\s|
|
)\.\.\.(\w)#", "\\1…\\2", $str); 
		
		// Run the translation array we defined above		
		$str = str_replace(array_keys($table), array_values($table), $str);
		
		// If there are any stray double quotes we'll catch them here
		
		$start = 0;
		
		while(TRUE)
		{
			$current = strpos(substr($str, $start), '"');
			
			if ($current === FALSE) break;
			
			$one_before = substr($str, $start+$current-1, 1);
			$one_after = substr($str, $start+$current+1, 1);
			
			if ( ! in_array($one_after, $space))
			{
				$str = str_replace(	$one_before.'"'.$one_after,
									$one_before."“".$one_after,
									$str);
			}
			elseif( ! in_array($one_before, $space))
			{
				$str = str_replace(	$one_before."'".$one_after,
									$one_before."”".$one_after,
									$str);
			}
			
			$start = $start+$current+2;
		}
		
		$start = 0;
		
		while(TRUE)
		{
			$current = strpos(substr($str, $start), "'");
			
			if ($current === FALSE) break;
			
			$one_before = substr($str, $start+$current-1, 1);
			$one_after = substr($str, $start+$current+1, 1);
			
			if ( ! in_array($one_after, $space))
			{
				$str = str_replace(	$one_before."'".$one_after,
									$one_before."‘".$one_after,
									$str);
			}
			elseif( ! in_array($one_before, $space))
			{
				$str = str_replace(	$one_before."'".$one_after,
									$one_before."’".$one_after,
									$str);
			}
			
			$start = $start+$current+2;
		}
		
		return $str;
	}
	
	// --------------------------------------------------------------------

	/**
	 * Format Newlines
	 *
	 * Converts newline characters into either 
 tags or 

	 *
	 */	
	function format_newlines($str)
	{
		if ($str == '')
		{
			return $str;
		}

		if (strpos($str, "\n") === FALSE)
		{
			return '
'.$str.'
';
		}
			
		$str = str_replace("\n\n", "
\n\n
", $str);
		$str = preg_replace("/([^\n])(\n)([^\n])/", "\\1
\\2\\3", $str);
		
		return '
'.$str.'
';
	}	
}

 
?>