/[suikacvs]/markup/html/scripting-parser/parser.html
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revision 1.12 by wakaba, Sun Apr 27 11:21:09 2008 UTC revision 1.21 by wakaba, Sun Jun 20 03:39:12 2010 UTC
# Line 2  Line 2 
2  <html lang=en>  <html lang=en>
3  <head>  <head>
4  <title>Live Scripting HTML Parser</title>  <title>Live Scripting HTML Parser</title>
5    <link rel=author href="http://suika.fam.cx/~wakaba/who?">
6    <link rel=license href="http://suika.fam.cx/c/gnu/gpl"
7        title="GNU GPL2 or later">
8  <style>  <style>
9    h1, h2 {    h1 {
10        margin: 0;
11        font-size: 150%;
12      }
13      h2 {
14      margin: 0;      margin: 0;
15      font-size: 100%;      font-size: 100%;
16    }    }
17    p, pre {    p {
18      margin: 0;      margin: 0 1em;
19    }    }
20    textarea {    textarea {
21      width: 100%;      width: 100%;
# Line 58  Line 65 
65    
66    var logIndentLevel = 0;    var logIndentLevel = 0;
67    function log (s) {    function log (s) {
68        var indent = '';
69      for (var i = 0; i < logIndentLevel; i++) {      for (var i = 0; i < logIndentLevel; i++) {
70        s = '  ' + s;        indent += '  ';
71      }      }
72        s = indent + s.replace (/\n/g, "\n" + indent);
73      document.logElement.appendChild (document.createTextNode (s + "\n"));      document.logElement.appendChild (document.createTextNode (s + "\n"));
74    } // log    } // log
75    
# Line 74  Line 83 
83        doc = new JSDocument (this);        doc = new JSDocument (this);
84        doc.manakaiIsHTML = true;        doc.manakaiIsHTML = true;
85      }      }
86        this.nextToken = [];
87      this.doc = doc;      this.doc = doc;
88      this.openElements = [doc];      this.openElements = [doc];
89      this.input = i;      this.input = i;
# Line 83  Line 93 
93    } // Parser    } // Parser
94    
95    Parser.prototype.getNextToken = function () {    Parser.prototype.getNextToken = function () {
96        if (this.nextToken.length) {
97          return this.nextToken.shift ();
98        }
99    
100      var p = this;      var p = this;
101      var i = this.input;      var i = this.input;
102      if (this.parseMode == 'script') {      if (this.parseMode == 'cdata') {
103          var tagName = this.endTagName;
104        var token;        var token;
105        if (p.insertionPoint <= 0) {        if (p.insertionPoint <= 0) {
106          return {type: 'abort'};          return {type: 'abort'};
# Line 103  Line 118 
118          return '';          return '';
119        });        });
120        if (token) return token;        if (token) return token;
121        i.s = i.s.replace (/^<\/[Ss][Cc][Rr][Ii][Pp][Tt]>/, function (s) {        var pattern = new RegExp ('^</' + tagName + '>', 'i');
122          i.s = i.s.replace (pattern, function (s) {
123          if (p.insertionPoint < s.length) {          if (p.insertionPoint < s.length) {
124            token = {type: 'abort'};            token = {type: 'abort'};
125            return s;            return s;
126          }          }
127          token = {type: 'end-tag', value: 'script'};          token = {type: 'end-tag', value: tagName};
128          p.insertionPoint -= s.length;          p.insertionPoint -= s.length;
129          return '';          return '';
130        });        });
131        if (token) return token;        if (token) return token;
132        var m;        var m;
133        if ((p.insertionPoint < '</script'.length) &&        if ((p.insertionPoint < ('</' + tagName).length) &&
134            (m = i.s.match (/^<\/([SCRIPTscript]+)/))) {            (m = i.s.match (/^<\/([A-Za-z]+)/))) {
135          var v = m[1].substring (0, p.insertionPoint).toLowerCase ();          var v = m[1].substring (0, p.insertionPoint).toLowerCase ();
136          if (v == 'script'.substring (0, p.insertionPoint - '</'.length)) {          if (v == tagName.substring (0, p.insertionPoint - '</'.length)) {
137            return {type: 'abort'};            return {type: 'abort'};
138          }          }
139        }        }
# Line 135  Line 151 
151      i.s = i.s.replace (/^<\/([^>]+)(?:>|$)/, function (s, e) {      i.s = i.s.replace (/^<\/([^>]+)(?:>|$)/, function (s, e) {
152        if (p.insertionPoint < s.length ||        if (p.insertionPoint < s.length ||
153            (p.insertionPoint <= s.length &&            (p.insertionPoint <= s.length &&
154             s.substring (s.length - 1, 1) != '>')) {             s.substring (s.length - 1, s.length) != '>')) {
155          token = {type: 'abort'};          token = {type: 'abort'};
156          return s;          return s;
157        }        }
# Line 147  Line 163 
163      i.s = i.s.replace (/^<([^>]+)(?:>|$)/, function (s, e) {      i.s = i.s.replace (/^<([^>]+)(?:>|$)/, function (s, e) {
164        if (p.insertionPoint < s.length ||        if (p.insertionPoint < s.length ||
165            (p.insertionPoint <= s.length &&            (p.insertionPoint <= s.length &&
166             s.substring (s.length - 1, 1) != '>')) {             s.substring (s.length - 1, s.length) != '>')) {
167          token = {type: 'abort'};          token = {type: 'abort'};
168          return s;          return s;
169        }        }
# Line 210  Line 226 
226        var token = this.getNextToken ();        var token = this.getNextToken ();
227        log ('token: ' + token.type + ' "' + token.value + '"');        log ('token: ' + token.type + ' "' + token.value + '"');
228    
229          if (this.cdataEndTagRequired) {
230            // Generic CDATA parsing algorithm
231    
232            if (token.type != 'abort') {
233              // 7.
234              if (token.type == 'end-tag' && token.value == this.endTagName) {
235                // 7.1. Ignores it.
236                //
237              } else {
238                // 7.2. Parse error.
239                log ('Parse error: no </' + this.endTagName + '>');
240                this.nextToken.unshift (token);
241              }
242              this.cdataEndTagRequired = false;
243              continue;
244            }
245          }
246    
247        if (token.type == 'start-tag') {        if (token.type == 'start-tag') {
248          if (token.value == 'script') {          if (token.value == 'script') {
249            // 1. Create an element for the token in the HTML namespace.            // 1. Create an element for the token in the HTML namespace.
# Line 222  Line 256 
256            el.manakaiParserInserted = true;            el.manakaiParserInserted = true;
257    
258            // 3. Switch the tokeniser's content model flag to the CDATA state.            // 3. Switch the tokeniser's content model flag to the CDATA state.
259            this.parseMode = 'script';            this.parseMode = 'cdata';
260              this.endTagName = 'script';
261    
262            // 4.1. Collect all the character tokens.            // 4.1. Collect all the character tokens.
263            while (true) {            while (true) {
# Line 236  Line 271 
271              // 4.2. Until it returns a token that is not a character token, or              // 4.2. Until it returns a token that is not a character token, or
272              // until it stops tokenising.              // until it stops tokenising.
273              } else if (token.type == 'eof' ||              } else if (token.type == 'eof' ||
274                         (token.type == 'end-tag' && token.value == 'script') ||                         token.type == 'end-tag' ||
275                         token.type == 'abort') {                         token.type == 'abort') {
276                // 6. Switched back to the PCDATA state.                // 6. Switched back to the PCDATA state.
277                this.parseMode = 'pcdata';                this.parseMode = 'pcdata';
278    
279                // 7.1. If the next token is not an end tag token with ...                // 7.1. If the next token is not an end tag token with ...
280                if (token.type != 'end-tag') {                if (!(token.type == 'end-tag' && token.value == 'script')) {
281                  // 7.2. This is a parse error.                  // 7.2. This is a parse error.
282                  log ('Parse error: no </' + 'script>');                  log ('Parse error: no </' + 'script>');
283                    this.nextToken.unshift (token);
284    
285                  // 7.3. Mark the script element as "already executed".                  // 7.3. Mark the script element as "already executed".
286                  el.manakaiAlreadyExecuted = true;                  el.manakaiAlreadyExecuted = true;
# Line 259  Line 295 
295            // 8.1. If the parser were originally created for the ...            // 8.1. If the parser were originally created for the ...
296            if (this.fragmentParsingMode) {            if (this.fragmentParsingMode) {
297              // 8.2. Mark the script element as "already executed" and ...              // 8.2. Mark the script element as "already executed" and ...
298              el.alreadyExecuted = true;              el.manakaiAlreadyExecuted = true;
299              continue;              continue;
300            }            }
301    
# Line 276  Line 312 
312            oldInsertionPoint += this.insertionPoint;            oldInsertionPoint += this.insertionPoint;
313            this.setInsertionPoint (oldInsertionPoint);            this.setInsertionPoint (oldInsertionPoint);
314    
315            // 12. If there is a script that will execute as soon as ...            // 12. If there is a pending external script
316            while (this.scriptExecutedWhenParserResumes) {            while (this.pendingExternalScript) {
317              // 12.1. If the tree construction stage is being called reentrantly              // 12.1. If the tree construction stage is being called reentrantly
318              if (this.reentrant) {              if (this.reentrant) {
319                log ('parse: abort (reentrance)');                log ('parse: abort (reentrance)');
# Line 287  Line 323 
323              // 12.2. Otherwise              // 12.2. Otherwise
324              } else {              } else {
325                // 1.                // 1.
326                var script = this.scriptExecutedWhenParserResumes;                var script = this.pendingExternalScript;
327                this.scriptExecutedWhenParserResumes = null;                this.pendingExternalScript = null;
328    
329                // 2. Pause until the script has completed loading.                // 2. Pause until the script has completed loading.
330                //                //
# Line 306  Line 342 
342                //                //
343              }              }
344            }            }
345            } else if (token.value == 'style' ||
346                       token.value == 'noscript' ||
347                       token.value == 'xmp') {
348              // 1. Create an element for the token in the HTML namespace.
349              var el = new JSElement (this.doc, token.value);
350    
351              // 2. Append the new element to the current node.
352              this.openElements[this.openElements.length - 1].appendChild (el);
353    
354              // 3. Switch the tokeniser's content model flag to the CDATA state.
355              this.parseMode = 'cdata';
356              this.endTagName = token.value;
357    
358              // 4.1. Collect all the character tokens.
359              while (true) {
360                var token = this.getNextToken ();
361                log ('token: ' + token.type + ' "' + token.value + '"');
362    
363                if (token.type == 'char') {
364                  // 5. Append a single Text node to the script element node.
365                  el.manakaiAppendText (token.value);
366    
367                // 4.2. Until it returns a token that is not a character token, or
368                // until it stops tokenising.
369                } else if (token.type == 'eof' ||
370                           token.type == 'end-tag' ||
371                           token.type == 'abort') {
372                  // 6. Switched back to the PCDATA state.
373                  this.parseMode = 'pcdata';
374    
375                  if (token.type == 'abort') {
376                    this.cdataEndTagRequired = true;
377                    break;
378                  }
379    
380                  // 7.1. If the next token is not an end tag token with ...
381                  if (!(token.type == 'end-tag' &&
382                        token.value == this.endTagName)) {
383                    // 7.2. This is a parse error.
384                    log ('Parse error: no </' + this.endTagName + '>');
385                    this.nextToken.unshift (token);
386    
387                    // 7.3. Mark the script element as "already executed".
388                    el.manakaiAlreadyExecuted = true;
389                  } else {
390                    // 7.4. Ignore it.
391                    //
392                  }
393                  break;
394                }
395              }
396          } else {          } else {
397            var el = new JSElement (this.doc, token.value);            var el = new JSElement (this.doc, token.value);
398            this.openElements[this.openElements.length - 1].appendChild (el);            this.openElements[this.openElements.length - 1].appendChild (el);
# Line 390  Line 477 
477    
478      log ('DOMContentLoaded event fired');      log ('DOMContentLoaded event fired');
479    
480      // "delays tha load event" things has completed:      // "delays the load event" things has completed:
481      // readyState = 'complete'      // readyState = 'complete'
482      log ('load event fired');      log ('load event fired');
483    
# Line 434  Line 521 
521        var doc = this.ownerDocument || this;        var doc = this.ownerDocument || this;
522        var p = doc._parser;        var p = doc._parser;
523    
524        // 1. Script type        // 1.The script's type
525          //
526    
527          // 2. The cript's character encoding
528        //        //
529    
530        // 2.1. If scripting is disabled        // 3.1. If without script
531        //        //
532        // 2.2. If the script element was created by an XML ... innerHTML ...        // 2.2. If the script element was created by an XML ... innerHTML ...
533        //        //
534        // 2.3. If the user agent does not support the scripting language ...        // 2.3. If the user agent does not support the scripting language ...
535        //        //
536        // 2.4. If the script element has its "already executed" flag set        if (false) {
       if (e.manakaiAlreadyExecuted) {  
537          // 2.5. Abort these steps at this point.          // 2.5. Abort these steps at this point.
538          log ('Running a script: aborted');          log ('Running a script: aborted (noscript)');
539          logIndentLevel--;          logIndentLevel--;
540          return e;          return e;
541        }        }
542    
543        // 3. Set the element's "already executed" flag.        // 4. Set the element's "already executed" flag.
544        e.manakaiAlreadyExecuted = true;        e.manakaiAlreadyExecuted = true;
545    
546        // 4. If the element has a src attribute, then a load for ...        // 5. If the element has a src attribute, then a load for ...
547        // TODO: load an external resource        // TODO: load an external resource
548    
549        // 5. The first of the following options:        // 5. The first of the following options:
550    
       // 5.1.  
551        if (/* TODO: If the document is still being parsed && */        if (/* TODO: If the document is still being parsed && */
552            e.defer && !e.async) {            e.defer && !e.async) {
553            // 6.1.
554          p.scriptsExecutedAfterParsing.push (e);          p.scriptsExecutedAfterParsing.push (e);
555          log ('Running a script: aborted (defer)');          log ('Running a script: aborted (defer)');
556        } else if (e.async && e.src != null) {        } else if (e.async && e.src != null) {
557            // 6.2.
558          p.scriptsExecutedAsynchronously.push (e);          p.scriptsExecutedAsynchronously.push (e);
559          log ('Running a script: aborted (async src)');          log ('Running a script: aborted (async src)');
560        } else if (e.async && e.src == null &&        } else if (e.async && e.src == null &&
561                   p.scriptsExecutedAsynchronously.length > 0) {                   p.scriptsExecutedAsynchronously.length > 0) {
562            // 6.3.
563          p.scriptsExecutedAsynchronously.push (e);          p.scriptsExecutedAsynchronously.push (e);
564          log ('Running a script: aborted (async)');          log ('Running a script: aborted (async)');
         // ISSUE: What is the difference with the case above?  
565        } else if (e.src != null && e.manakaiParserInserted) {        } else if (e.src != null && e.manakaiParserInserted) {
566          if (p.scriptExecutedWhenParserResumes) {          // 6.4.
567            log ('Error: There is a script that will execute as soon as the parser resumes.');          if (p.pendingExternalScript) {
568              log ('Error: There is a pending external script.');
569          }          }
570          p.scriptExecutedWhenParserResumes = e;          p.pendingExternalScript = e;
571          log ('Running a script: aborted (src parser-inserted)');          log ('Running a script: aborted (src parser-inserted)');
572        } else if (e.src != null) {        } else if (e.src != null) {
573            // 6.5.
574          p.scriptsExecutedSoon.push (e);          p.scriptsExecutedSoon.push (e);
575          log ('Running a script: aborted (src)');          log ('Running a script: aborted (src)');
576        } else {        } else {
577            // 6.6.
578          executeScript (doc, e); // even if other scripts are already executing.          executeScript (doc, e); // even if other scripts are already executing.
579        }        }
580    
# Line 511  Line 604 
604      }      }
605    
606      // If the load was successful      // If the load was successful
     log ('load event fired at the script element');  
607    
608      if (true) {      if (true) {
609      // Scripting is enabled, Document.designMode is disabled,      // Scripting is enabled, Document.designMode is disabled,
# Line 520  Line 612 
612        parseAndRunScript (doc, s);        parseAndRunScript (doc, s);
613      }      }
614    
615        log ('load event fired at the script element');
616    
617      log ('executing a script block: end');      log ('executing a script block: end');
618    } // executeScript    } // executeScript
619    
# Line 557  Line 651 
651          doc.write.apply (doc, args);          doc.write.apply (doc, args);
652          return '';          return '';
653        });        });
654        s = s.replace (/^\s*var\s+s\s*=\s*document\.createElement\s*\(\s*['"]script['"]\s*\)\s*;\s*s\.src\s*=\s*(?:'(javascript:[^']*)'|"(javascript:[^"]*)")\s*;\s*document\.documentElement\.appendChild\s*\(\s*s\s*\)\s*;\s*/,        var noDocumentElement = false;
655          s = s.replace (/^\s*var\s+s\s*=\s*document\.createElement\s*\(\s*['"]script['"]\s*\)\s*;\s*s\.src\s*=\s*(?:'([^']*)'|"([^"]*)")\s*;\s*document\.documentElement\.appendChild\s*\(\s*s\s*\)\s*;\s*/,
656        function (s, t, u) {        function (s, t, u) {
657          matched = true;          matched = true;
658          var args = [unescapeJSLiteral (t ? t : u)];          var args = [unescapeJSLiteral (t ? t : u)];
659          doc._insertExternalScript.apply (doc, args);          noDocumentElement = !doc._insertExternalScript.apply (doc, args);
660            return '';
661          });
662          if (noDocumentElement) {
663            log ('Script error: documentElement is null');
664            break;
665          }
666          s = s.replace (/^\s*w\s*\(\s*document\.documentElement\.innerHTML\s*\)\s*;\s*/,
667          function (s, t) {
668            matched = true;
669            log (dumpTree (doc, ''));
670          return '';          return '';
671        });        });
672        if (s == '') break;        if (s == '') break;
# Line 646  Line 751 
751    }; // document.open    }; // document.open
752    
753    JSDocument.prototype.write = function () {    JSDocument.prototype.write = function () {
754        log ('document.write: start');
755      logIndentLevel++;      logIndentLevel++;
756    
757      var p = this._parser;      var p = this._parser;
# Line 665  Line 771 
771          + p.input.s.substring (p.insertionPoint, p.input.s.length);          + p.input.s.substring (p.insertionPoint, p.input.s.length);
772      p.insertionPoint += s.length;      p.insertionPoint += s.length;
773    
774      // 3. If there is a script that will execute as soon as the parser resumes      // 3. If there is a pending external script
775      if (p.scriptExecutedAfterParserResumes) {      if (p.pendingExternalScript) {
776        log ('document.write: processed later (there is an unprocessed <script src>)');        log ('document.write: processed later (there is an unprocessed <script src>)');
777        logIndentLevel--;        logIndentLevel--;
778          log ('document.write: return');
779        return;        return;
780      }      }
781    
# Line 682  Line 789 
789      // to do something here?      // to do something here?
790    
791      // 5. Return      // 5. Return
792        logIndentLevel--;
793      log ('document.write: return');      log ('document.write: return');
794    
     logIndentLevel--;  
795      return;      return;
796    }; // document.write    }; // document.write
797    
798    JSDocument.prototype._insertExternalScript = function (uri) {    JSDocument.prototype._insertExternalScript = function (uri) {
799      var s = new JSElement (this, 'script');      var s = new JSElement (this, 'script');
800      s.src = uri;      s.src = uri;
801      this.documentElement.appendChild (s);      if (this.documentElement) {
802          this.documentElement.appendChild (s);
803          return true;
804        } else {
805          return false;
806        }
807    }; // _insertExternalScript    }; // _insertExternalScript
808    
809    JSDocument.prototype.__defineGetter__ ('documentElement', function () {    JSDocument.prototype.__defineGetter__ ('documentElement', function () {
# Line 778  document.write ('aaaaaaa&lt;/p>&lt;scrip Line 890  document.write ('aaaaaaa&lt;/p>&lt;scrip
890    
891  <h2 id=notes>Notes</h2>  <h2 id=notes>Notes</h2>
892    
893  <p>This is a <em>simplified</em> implementation of  <p>This is a <em>simplified</em> implementation of <a
894  <a href="http://www.whatwg.org/specs/web-apps/current-work/#parsing">HTML5  href="http://www.whatwg.org/specs/web-apps/current-work/#parsing">HTML5
895  Parsing Algorithm</a>.  It only implements script-related part of the  Parsing Algorithm</a> (revision 2138).  It only implements
896  algorithm.  Especially, this parser:  scripting-related parts of the algorithm.  Especially, this parser:
897    
898  <ul>  <ul>
899  <li>Does not support <code>DOCTYPE</code> and comment tokens.  <li>Does not support <code>DOCTYPE</code> and comment tokens.
900  <li>Does not support entities except for <code>&amp;quot;</code>,  <li>Does not support entities except for <code>&amp;quot;</code>,
# Line 791  algorithm.  Especially, this parser: Line 904  algorithm.  Especially, this parser:
904  algorithm, and so on.  algorithm, and so on.
905  <li>Does not raise parse errors for invalid attribute specifications in start  <li>Does not raise parse errors for invalid attribute specifications in start
906  or end tags.  or end tags.
907  <li>Does not support CDATA/PCDATA element other than <code>script</code>.  <li>Does not support RCDATA elements (<code>title</code> and
908    <code>textarea</code>).
909    <li>Does not strip the first newline in <code>pre</code>,
910    <code>listing</code>, and <code>textarea</code> elements.
911  <li>Does not support <code>&lt;!--</code>..<code>--></code> parsing rule  <li>Does not support <code>&lt;!--</code>..<code>--></code> parsing rule
912  in <code>script</code> element.  in CDATA/RCDATA elements.
913  <li>Does not support foreign (SVG or MathML) elements.  <li>Does not support foreign (SVG or MathML) elements.
914  <li>Only supports <code>script</code> <code>type</code>  <li>Only supports <code>script</code> <code>type</code>
915  <code>text/javascript</code>.  <code>type</code> and <code>language</code>  <code>text/javascript</code>.  <code>type</code> and <code>language</code>
# Line 806  introduced, followed, or separated by wh Line 922  introduced, followed, or separated by wh
922    <li><code>var s = document.createElement ("script");    <li><code>var s = document.createElement ("script");
923              s.src = "<var>string</var>";              s.src = "<var>string</var>";
924              document.documentElement.appendChild (s);</code>              document.documentElement.appendChild (s);</code>
925      <li><code>w (document.documentElement.innerHTML);</code> (This statement
926      can be used to dump the document, even when the document has no
927      document element.  The output format is the tree dump format used
928      in html5lib test data, not <abbr>HTML</abbr>.)
929    </ul>    </ul>
930  Note that strings may be delimited by <code>'</code>s instead of  Note that strings may be delimited by <code>'</code>s instead of
931  <code>"</code>s.  <code>"</code>s.
# Line 831  when it is inserted into the document, n Line 951  when it is inserted into the document, n
951  executed.  Currently it does not matter, since we don't allow dynamic  executed.  Currently it does not matter, since we don't allow dynamic
952  modification to the |src| content/DOM attribute value yet. -->  modification to the |src| content/DOM attribute value yet. -->
953    
954  <!-- TODO: license -->  <p>See also
955    <a href="http://suika.fam.cx/gate/2005/sw/Live%20Scripting%20HTML%20Parser">SuikaWiki:
956    Live Scripting HTML Parser</a>.
957    
958  </body>  </body>
 </html>  
959    </html>
960    <!-- $Date$ -->
961    <!--
962    
963    Copyright 2008 Wakaba <w@suika.fam.cx>
964    
965    This program is free software; you can redistribute it and/or
966    modify it under the terms of the GNU General Public License
967    as published by the Free Software Foundation; either version 2
968    of the License, or (at your option) any later version.
969    
970    This program is distributed in the hope that it will be useful,
971    but WITHOUT ANY WARRANTY; without even the implied warranty of
972    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
973    GNU General Public License for more details.
974    
975    You should have received a copy of the GNU General Public License
976    along with this program; if not, write to the Free Software
977    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
978    
979    -->

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