HTML parser

<?
// This code has been published under GPL version 2 or higher
// so you are free to modify etc etc
// Please drop me a line when you use it in your code or
// when you modify it
// I will be making changes to it and include more comments
// [email protected]
// btw NO WARRANTIES

// function parsehtml
// based on the libhtmlparse libary by
// Mooneer Salem ([email protected])
// should be rewritten to be an extension to php4

// just a debug print function
// cause tags aren't that easy to output

// Version 0.90b

function dp($txt, $var)
{
	$trans = get_html_translation_table(HTML_ENTITIES);
	$encoded = strtr($var, $trans);
	printf("<br>%s is now: %s", $txt, $encoded);
}

function parse($html) {
	$html2 = $html;
	$tmp = $html2;
	
	$c=0;
	
	while (($tmp[$c] || $c < strlen($tmp))) {

		if ($tmp[$c] == '<' || $istag) {
			$istag = 0;
			
			if ($tmp[$c++] == '!') {
				// comment
				if ($tmp[$c++] == '-' || $tmp[$c+1] == '-') {
					$c+=2;
					// trim($tmp) ??
					while ($tmp[$c] == ' ') $c++;
					$c--;
					
					
					startCommentCallback();
					
					// find the end of the comment
					$t = $c;
					while (($tmp[$t] || $t < strlen($tmp)) && !($tmp[$t] == '-' && $tmp[$t++] == '-' && $tmp[$t+2] == '>')) $t++;
					if (($tmp[$t] || $t < strlen($tmp))) {
						while ($tmp[$t] == ' ') $t--;
						$comment = substr($tmp, $c, $t-$c);
						while ($tmp[$t] == ' ') $t++;
						$t+=2;
						$c = $t;
					}
					
					commentCallback($comment);
					endCommentCallback();
					
					$c++;
				} else {
					$c--;
					// handle starttag
				}
			} elseif ($tmp[$c] == '/' || $tmp[$c-1] == '/') {
				if ($tmp[$c] == '/') $c++;
				$t=$c;
				while (($tmp[$t] || $t < strlen($tmp)) && $tmp[$t] != '>') $t++;
				
				$tag = substr($tmp,$c,$t-$c);
				endCallback($tag);
				$t++;
				$c = $t;
				continue;
			} else {
				// starttag here
				// maybe inseperate function because of above
				if ($tmp[$c-1] != '<') $c--;
				
				// comment function from above in seperate function call.
				if ($tmp[$c] == '!' && $tmp[$c++] == '-') comment();
			
				$t = $c;
				$q = $c;    // $q belongs to $tag[$q]
				$tagstart = $c;
					
				$tag = substr($tmp,$c);

				while ($tmp[$t] != '>' && $tmp[$t] != ' ') $t++;
				if ($tmp[$t] == '>') {
					$tag = substr($tmp, $c, $t-$c);
					if ($tag[0] == '!') {
						$tag = substr($tmp,$c+1, $t-($c+1));
						$tagstart = $c+1;
						declCallback($tag, "", 0);
					} else startCallback($tag, "", 0);
					
					// TEST was c = t
					$c = $t+1;
					
					continue;
				} elseif ($tmp[$c] == ' ') {
					while ($tmp[$c] == ' ') $c++;
				} else {
					if ($tmp[$q] == '!') {
						$q++;
						$tag = substr($tmp, $q, $q-$c);
						declCallback ($tag, "", 0);
					} else {
						declCallback ($tag, "", 0);
					}
					break;
				}
				
				unset($args);
				$numargs = 0;
				
				while (($tmp[$c] || $c < strlen($tmp))) {
					$istrue = 0;
					$tagended = 0;
					while ($tmp[$c] == ' ') $c++;
					if (!$tmp[$c-1] == ' ') $c--;
					
					// $arg = start of argument
					$arg = $c;
							
					// $q is used to find end of argument
					if ($tmp[$arg] == '"' || $tmp[$arg] == ''') {
						$c++;
						$arg = $c;
						while (($tmp[$c] || $c < strlen($tmp)) && !($tmp[$c] == '"' && $tmp[$c-1] != '' && $tmp[$c] != ''')) $c++;
						// add arguments to table?
						
						if ($tmp[$c] != '>') continue;
						if ($tmp[$c+1] == '>') {
							$c++;
						}
						break;
					}
					
					$val = "";
					while ($tmp[$c] != '=' && $tmp[$c] != ' ' && $tmp[$c] != '>') $c++;
					if ($tmp[$c] != ' ' && $tmp[$c] != '>') $istrue = 1;
					if ($tmp[$c] == '>') $tagended = 1;
					
					$q = $c;
					$c++;
					
					if ($istrue) {
						if ($tmp[$c] != ''' && $tmp[$c] != '"') {
							while ($tmp[$c] != ' ' && $tmp[$c] != '>') $c++;
							if ($tmp[$c] == '>') {
								$val = substr($tmp,$q, $c-$q);
							} else {
								$c++;
								$val = substr($tmp, $c, $c-$q);
								continue;
							}
						} else {
							$c++;
							while ($tmp[$c] && ($tmp[$c] != ''' || ($tmp[$c] == ''' && $tmp[$c-1] == '')) && ($tmp[$c] != '"' || ($tmp[$c] == '"' && $tmp[$c-1] == ''))) $c++;
							if ($tmp[$c] == '>') {
								$val = substr($tmp,$q, $c-$q);
								$c++;
								// add args
								break;
								
							} elseif ($tmp[$c+1] == '>') {
								$val = substr($tmp, $q, $c-$q);
								$c++;
								// add args
								break;
							} else {
								$val = substr($tmp, $q, $c-$q);
								$c+=2;
								// add args
							}
						}
					} else {
						// add args
						if (!$tagended) continue;
						$tagended = 0;
						$c--;
						break;
					}
				}
				
				// is q allowed here?
				$q=0;
				if ($tag[$q] == '!') {
					$q++;
					// FIXME
					$tag = substr($tag, $q);
					// FIX THIS TOO
					declCallback($tag, "", 0);
				} else {
					// and this
					startCallback($tag, "", 0);
				}
				
				// clear arg list;
				$c++;
				continue;
			}
		} else {
			// check for newline char						
			if ($tmp[$c] == 'n') {
				$c++;
				continue;
			}
			
			$text = $tmp;
			$q = $c;
			
			if ($text[$q] == '!') {
				$q--;
				if ($text[$q-1] == '<') {
					$q--;
					continue;
				}
			}				
			
			while ($tmp[$c] == ' ' && $tmp[$c] != '<' && ($tmp[$c] || $c < strlen($tmp))) $c++;
			if ($tmp[$c] == '<' && $tmp[$c+1]) {
				continue;
			} else if (!($tmp[$c] || $c < strlen($tmp))) break;
			
			// text start
			textStartCallback();
			
			for (;;) {
				while (($tmp[$c] || $c < strlen($tmp)) && $tmp[$c] != '<') $c++;
				if ($tmp[$c] == '<') {
					if ($tmp[$c+1] == ' ') {
						$c++;
						continue;
					} else $istag = 1;
				}
				break;
			}
				
			$text = substr($tmp, $q, $c-$q);
			
			// text callback
			textCallback($text);
			
			// text end
			textEndCallback();
			$c++;
			continue;
			
			}
		
		}
				
		return;
}
	
?>