Rich Text Format parser

<?
	// use tabstop=4 

	/*
		Rich Text Format - Parsing Class
		================================

		(c) 2000 Markus Fischer
		<[email protected]>
		   http://josefine.ben.tuwien.ac.at/~mfischer/

		Latest versions of this class can always be found at
			http://josefine.ben.tuwien.ac.at/~mfischer/developing/php/rtf/rtfclass.phps
		Testing suite is available at
			http://josefine.ben.tuwien.ac.at/~mfischer/developing/php/rtf/

		License: GPLv2

		Specification:
			http://msdn.microsoft.com/library/default.asp?URL=/library/specs/rtfspec.htm

		General Notes:
		==============
		Unknown or unspupported control symbols are silently ignored

		Group stacking is still not supported :(
			group stack logic implemented; however not really used yet

		Example on how to use this class:
		=================================

		$r = new rtf( stripslashes( $rtf));
		$r->output( "xml");
		$r->parse();
		if( count( $r->err) == 0) // no errors detected
			echo $r->out;
			
		History:
		========
		Sat Nov 25 09:52:12 CET 2000	mfischer
			First version which has useable but only well-formed xml output; rtf
			data structure is only logically rebuild, no real parsing yet

		Mon Nov 27 16:17:18 CET 2000	mfischer
			Wrote handler for plain control word (thanks to Peter Kursawe for this
			one)

		Tue Nov 28 02:22:16 CET 2000	mfischer
			Implemented alignment (left, center, right) with HTML <DIV .. tags
			Also implemented translation for < and > character when outputting html or xml

		Remarks:
		========
		This class and all work done here is dedicated to Tatjana.
	*/

	/* was just a brainlag suggestion of my inner link; don't know if I'll use it */
	class rtfState {
		var $bold;
		var $italic;
		var $underlined;
	}

	class rtf {
		var $rtf;		// rtf core stream
		var $len;		// length in characters of the stream (get performace due avoiding calling strlen everytime)
		var $err = array();		// array of error message, no entities on no error

		var $wantXML;	// convert to XML
		var $wantHTML;	// convert to HTML

		// the only variable which should be accessed from the outside
		var $out;		// output data stream (depends on which $wantXXXXX is set to true
		var $outstyles;	// htmlified styles (generated after parsing if wantHTML
		var $styles;	// if wantHTML, stylesheet definitions are put in here

		// internal parser variables --------------------------------
		// control word variables
		var $cword;		// holds the current (or last) control word, depending on $cw
		var $cw;		// are we currently parsing a control word ?
		var $cfirst;	// could this be the first character ? so watch out for control symbols

		var $flags = array();		// parser flags

		var $queue;		// every character which is no sepcial char, not belongs to a control word/symbol; is generally considered being 'plain'

		var $stack = array();	// group stack

		/* keywords which don't follw the specification (used by Word '97 - 2000) */
		// not yet used
		var $control_exception = array(
			"clFitText",
			"clftsWidth(-?[0-9]+)?",
			"clNoWrap(-?[0-9]+)?",
			"clwWidth(-?[0-9]+)?",
			"tdfrmtxtBottom(-?[0-9]+)?",
			"tdfrmtxtLeft(-?[0-9]+)?",
			"tdfrmtxtRight(-?[0-9]+)?",
			"tdfrmtxtTop(-?[0-9]+)?",
			"trftsWidthA(-?[0-9]+)?",
			"trftsWidthB(-?[0-9]+)?",
			"trftsWidth(-?[0-9]+)?",
			"trwWithA(-?[0-9]+)?",
			"trwWithB(-?[0-9]+)?",
			"trwWith(-?[0-9]+)?",
			"spectspecifygen(-?[0-9]+)?"
			);

		var $charset_table = array(
			"0"	=>	"ANSI",
			"1"	=>	"Default",
			"2"	=>	"Symbol",
			"77" =>	"Mac",
			"128" =>	"Shift Jis",
			"129" =>	"Hangul",
			"130" =>	"Johab",
			"134" =>	"GB2312",
			"136" =>	"Big5",
			"161" =>	"Greek",
			"162" =>	"Turkish",
			"163" =>	"Vietnamese",
			"177" =>	"Hebrew",
			"178" =>	"Arabic",
			"179" =>	"Arabic Traditional",
			"180" =>	"Arabic user",
			"181" =>	"Hebrew user",
			"186" =>	"Baltic",
			"204" =>	"Russion",
			"222" =>	"Thai",
			"238" =>	"Eastern European",
			"255" =>	"PC 437",
			"255" =>	"OEM"
		);

		/* note: the only conversion table used */
		var $fontmodifier_table = array(
			"bold"	=>	"b",
			"italic"	=> "i",
			"underlined"	=> "u",
			"strikethru"	=> "strike"
		);

		/*
			Class Constructor:
			Takes as argument the raw RTF stream
			(Note under certain circumstances the stream has to be stripslash'ed before handling over)
			Initialises some class-global variables
		*/
		function rtf( $data) {
			$this->len = strlen( $data);
			$this->rtf = $data;

			$this->wantXML = false;
			$this->wantHTML = false;

			$this->out = "";
			$this->outstyles = "";
			$this->styles = array();
			$this->text = "";

			if( $this->len == 0)
				array_push( $this->err, "No data in stream found");
		}

		function parserInit() {
			/*
				Default values according to the specs
			*/
			$this->flags = array(
				"fontsize"	=>	24,
				"beginparagraph"	=> true
			);
		}
		
		/*
			Sets the output type
		*/
		function output( $typ) {
			switch( $typ) {
				case "xml": $this->wantXML = true; break;
				case "html": $this->wantHTML = true; break;
				default: break;
			}
		}

		function parseControl( $control, $parameter) {
			switch( $control) {
				// font table definition start
				case "fonttbl":
					$this->flags["fonttbl"] = true;	// signal fonttable control words they are allowed to behave as expected
					break;
				// define or set font
				case "f":
					if( $this->flags["fonttbl"]) {	// if its set, the fonttable definition is written to; else its read from
						$this->flags["fonttbl_current_write"] = $parameter;
					} else {
						$this->flags["fonttbl_current_read"] = $parameter;
					}
					break;
				case "fcharset":
					// this is for preparing flushQueue; it then moves the Queue to $this->fonttable .. instead to formatted output
					$this->flags["fonttbl_want_fcharset"] = $parameter;
					break;
				case "fs":
					// sets the current fontsize; is used by stylesheets (which are therefore generated on the fly
					$this->flags["fontsize"] = $parameter;
					break;
				// handle alignment
				case "qc":
					$this->flags["alignment"] = "center";
					break;
				case "qr":
					$this->flags["alignment"] = "right";
					break;
				// reset paragraph settings ( only alignment)
				case "pard":
					$this->flags["alignment"] = "";
					break;
				// define new paragraph (for now, thats a simple break in html)
				case "par":
					// begin new line
					$this->flags["beginparagraph"] = true;
					if( $this->wantHTML) {
						$this->out .= "</div>";
					}
					break;
				// bold
				case "bnone":
					$parameter = "0";
				case "b":
					// haven'y yet figured out WHY I need a (string)-cast here ... hm
					if( (string)$parameter == "0")
						$this->flags["bold"] = false;
					else
						$this->flags["bold"] = true;
					break;

				// underlined
				case "ulnone":
					$parameter = "0";
				case "ul":
					if( (string)$parameter == "0")
						$this->flags["underlined"] = false;
					else
						$this->flags["underlined"] = true;
					break;
				
				// italic
				case "inone":
					$parameter = "0";
				case "i":
					if( (string)$parameter == "0")
						$this->flags["italic"] = false;
					else
						$this->flags["italic"] = true;
					break;

				// strikethru
				case "strikenone":
					$parameter = "0";
				case "strike":
					if( (string)$parameter == "0")
						$this->flags["strikethru"] = false;
					else
						$this->flags["strikethru"] = true;
					break;

				// reset all font modifiers and fontsize to 12
				case "plain":
					$this->flags["bold"] = false;
					$this->flags["italic"] = false;
					$this->flags["underlined"] = false;
					$this->flags["strikethru"] = false;
					$this->flags["fontsize"] = 12;
					break;
			}
		}

		/*
			Dispatch the control word to the output stream
		*/
		function flushControl() {
			if( ereg( "^([A-Za-z]+)(-?[0-9]*) ?$", $this->cword, $match)) {

				$this->parseControl( $match[1], $match[2]);

				if( $this->wantXML) {
					$this->out.="<control word="".$match[1].""";
					if( strlen( $match[2]) > 0)
						$this->out.=" param="".$match[2].""";
					$this->out.="/>";
				}
			}
		}

		/*
			If output stream supports comments, dispatch it
		*/
		function flushComment( $comment) {
			if( $this->wantXML || $this->wantHTML) {
				$this->out.="<!-- ".$comment." -->";
			}
		}

		/*
			Dispatch start/end of logical rtf groups
			(not every output type needs it; merely debugging purpose)
		*/
		function flushGroup( $state) {
			if( $state == "open") {

				/* push onto the stack */
				array_push( $this->stack, $this->flags);
			
				if( $this->wantXML)
					$this->out.="<group>";
			}
			if( $state == "close") {

				/* pop from the stack */
				$this->last_flags = $this->flags;
				$this->flags = array_pop( $this->stack);

				$this->flags["fonttbl_current_write"] = ""; // on group close, no more fontdefinition will be written to this id
															// this is not really the right way to do it !
															// of course a '}' not necessarily donates a fonttable end; a fonttable
															// group at least *can* contain sub-groups
															// therefore an stacked approach is heavily needed
				$this->flags["fonttbl"] = false; // no matter what you do, if a group closes, its fonttbl definition is closed too

				if( $this->wantXML)
					$this->out.="</group>";
			}
		}

		function flushHead() {
			if( $this->wantXML)
				$this->out.="<rtf>";
		}

		function flushBottom() {
			if( $this->wantXML)
				$this->out.="</rtf>";
		}


		function checkHtmlSpanContent( $command) {
			reset( $this->fontmodifier_table);
			while( list( $rtf, $html) = each( $this->fontmodifier_table)) {
				if( $this->flags[$rtf] == true) {
					if( $command == "start")
						$this->out .= "<".$html.">";
					else
						$this->out .= "</".$html.">";
				}
			}
		}
		/*
			flush text in queue
		*/
		function flushQueue() {
			if( strlen( $this->queue)) {
				// processing logic
				if( ereg( "^[0-9]+$", $this->flags["fonttbl_want_fcharset"])) {
					$this->fonttable[$this->flags["fonttbl_want_fcharset"]]["charset"] = $this->queue;
					$this->flags["fonttbl_want_fcharset"] = "";
					$this->queue = "";
				}
				
				// output logic
				if( strlen( $this->queue)) {
					/*
						Everything which passes this is (or, at leat, *should*) be only outputted plaintext
						Thats why we can safely add the css-stylesheet when using wantHTML
					*/
					if( $this->wantXML)
						$this->out.= "<plain>".$this->queue."</plain>";

					if( $this->wantHTML) {
						// only output html if a valid (for now, just numeric;) fonttable is given
						if( ereg( "^[0-9]+$", $this->flags["fonttbl_current_read"])) {
							
							if( $this->flags["beginparagraph"] == true) {
								$this->flags["beginparagraph"] = false;
								$this->out .= "<div align="";
								switch( $this->flags["alignment"]) {
									case "right":
										$this->out .= "right";
										break;
									case "center":
										$this->out .= "center";
										break;
									case "left":
									default:
										$this->out .= "left";
								}
								$this->out .= "">";
							}
							
							/* define new style for that span */
							$this->styles["f".$this->flags["fonttbl_current_read"]."s".$this->flags["fontsize"]] = "font-family:".$this->fonttable[$this->flags["fonttbl_current_read"]]["charset"]." font-size:".$this->flags["fontsize"].";";
							/* write span start */
							$this->out .= "<span class="f".$this->flags["fonttbl_current_read"]."s".$this->flags["fontsize"]."">";

							/* check if the span content has a modifier */
							$this->checkHtmlSpanContent( "start");
							/* write span content */
							$this->out .= $this->queue;
							/* close modifiers */
							$this->checkHtmlSpanContent( "stop");
							/* close span */
							"</span>";
						}
					}
					$this->queue = "";
				}
			}
		}

		/*
			handle special charactes like 'ef
		*/
		function flushSpecial( $special) {
			if( strlen( $special) == 2) {
				if( $this->wantXML)
					$this->out .= "<special value="".$special.""/>";
			}
		}

		/*
			Output errors at end
		*/
		function flushErrors() {
			if( count( $this->err) > 0) {
				if( $this->wantXML) {
						$this->out .= "<errors>";
						while( list($num,$value) = each( $this->err)) {
							$this->out .= "<message>".$value."</message>";
						}
						$this->out .= "</errors>";
				}
			}
		}

		function makeStyles() {
			$this->outstyles = "<style type="text/css"><!--n";
			reset( $this->styles);
			while( list( $stylename, $styleattrib) = each( $this->styles)) {
				$this->outstyles .= ".".$stylename." { ".$styleattrib." }n";
			}
			$this->outstyles .= "--></style>n";
		}

		/*
			finally ..

			How this parser (is supposed) to work:
			======================================
			This parse simple starts at the beginning of the rtf core stream, catches every
			controlling character {,} and , automatically builds control words and control
			symbols during his livetime, trashes every other character into the plain text
			queue
		*/
		function parse() {

			$this->parserInit();

			$i = 0;
			$this->cw= false;	// flag if control word is currently parsed
			$this->cfirst = false;// first control character ?
			$this->cword = "";	// last or current control word ( depends on $this->cw

			$this->queue = "";		// plain text data found during parsing

			$this->flushHead();

			while( $i < $this->len) {
				switch( $this->rtf[$i]) {
					case "{":	if( $this->cw) {
									$this->flushControl();
									$this->cw= false; $this->cfirst = false;
								} else 
									$this->flushQueue();

								$this->flushGroup( "open");
								break;
					case "}":	if( $this->cw) {
									$this->flushControl();
									$this->cw= false; $this->cfirst = false;
								} else
									$this->flushQueue();

								$this->flushGroup( "close");
								break;
					case "":	if( $this->cfirst) {	// catches '' 
									$this->flushComment( "true, ".$i);
									$this->queue .= '';
									$this->cfirst = false;
									$this->cw= false;
									break;
								}
								if( $this->cw) {
									$this->flushControl();
								} else 
									$this->flushQueue();
								$this->cw = true;
								$this->cfirst = true;
								$this->cword = "";
								break;
					default:	
								if( (ord( $this->rtf[$i]) == 10) || (ord($this->rtf[$i]) == 13)) break; // eat line breaks
								if( $this->cw) {	// active control word ?
									/*
										Watch the RE: there's an optional space at the end which IS part of
										the control word (but actually its ignored by flushControl)
									*/
									if( ereg( "^[a-zA-Z0-9-]?$", $this->rtf[$i])) { // continue parsing
										$this->cword .= $this->rtf[$i];
										$this->cfirst = false;
									} else {
										/*
											Control word could be a 'control symbol', like ~ or * etc.
										*/
										$specialmatch = false;
										if( $this->cfirst) {
											if( $this->rtf[$i] == ''') { // expect to get some special chars
												$this->flushQueue();
												$this->flushSpecial( $this->rtf[$i+1].$this->rtf[$i+2]);
												$i+=2;
												$specialmatch = true;
												$this->cw = false; $this->cfirst = false; $this->cword = "";
											} else 
											if( ereg( "^[{}*]$", $this->rtf[$i])) {
												$this->flushComment( "control symbols not yet handled");
												$specialmatch = true;
											}
											$this->cfirst = false;
										} else {
											if( $this->rtf[$i] == ' ') {	// space delimtes control words, so just discard it and flush the controlword
												$this->cw = false;
												$this->flushControl();
												break;
											}
										}
										if( ! $specialmatch) {
											$this->flushControl();
											$this->cw = false; $this->cfirst = false;
											/*
												The current character is a delimeter, but is NOT
												part of the control word so we hop one step back
												in the stream and process it again
											*/
											$i--;
										}
									}
								} else {
									// < and > need translation before putting into queue when XML or HTML is wanted
									if( ($this->wantHTML) || ($this->wantXML)) {
										switch( $this->rtf[$i]) {
											case "<":
												$this->queue .= "&lt;";
												break;
											case ">":
												$this->queue .= "&gt;";
												break;
											default:
												$this->queue .= $this->rtf[$i];
												break;
										}
									} else 
										$this->queue .= $this->rtf[$i];
								}
									
				}
				$i++;
			}
			$this->flushQueue();
			$this->flushErrors();
			$this->flushBottom();

			if( $this->wantHTML) {
				$this->makeStyles();
			}
		}
	}
?>