html/scripting-parser/parser.html

<!DOCTYPE HTML>
<html lang=en>
<head>
<title>Demo of HTML5 Parsing Algorithm with Scripting Enabled</title>
<style>
  h1, h2 {
    margin: 0;
    font-size: 100%;
  }
  p, pre {
    margin: 0;
  }
  textarea {
    width: 100%;
    -width: 99%;
    height: 10em;
  }
  output {
    display: block;
    font-family: monospace;
    white-space: -moz-pre-wrap;
    white-space: pre-wrap;
  }
</style>
<script>
  var delayedUpdater = 0;

  function update () {
    if (delayedUpdater) {
      clearTimeout (delayedUpdater);
      delayedUpdater = 0;
    }
    delayedUpdater = setTimeout (update2, 100);
  } // update

  function update2 () {
    document.logElement.textContent = '';
    var v = document.sourceElement.value;
    var p = new Parser (new InputStream (v));
    var doc = p.doc;
    p.parse ();
    log (dumpTree (doc, ''));

    document.links['permalink'].href
        = location.href + '?s=' + encodeURIComponent (v);
  } // update2

  var logIndentLevel = 0;
  function log (s) {
    for (var i = 0; i < logIndentLevel; i++) {
      s = '  ' + s;
    }
    document.logElement.appendChild (document.createTextNode (s + "\n"));
  } // log

  function InputStream (s) {
    this.s = s;
  } // InputStream

  function Parser (i, doc) {
    this.parseMode = 'pcdata';
    if (!doc) {
      doc = new JSDocument (this);
      doc.manakaiIsHTML = true;
    }
    this.doc = doc;
    this.openElements = [doc];
    this.in = i;
    this.scriptsExecutedAfterParsing = [];
  } // Parser

  Parser.prototype.getNextToken = function () {
    var p = this;
    var i = this.in;
    if (this.parseMode == 'script') {
      var token;
      if (p.insertionPoint <= 0) {
        return {type: 'abort'};
      }
      i.s = i.s.replace (/^([^<]+)/,
      function (s, t) {
        if (0 < p.insertionPoint && p.insertionPoint < t.length) {
          token = {type: 'char', value: t.substring (0, p.insertionPoint)};
          var ip = p.insertionPoint;
          p.insertionPoint = 0;
          return t.substring (ip, t.length);
        }
        token = {type: 'char', value: t};
        p.insertionPoint -= t.length;
        return '';
      });
      if (token) return token;
      i.s = i.s.replace (/^<\/[Ss][Cc][Rr][Ii][Pp][Tt]>/, function (s) {
        if (p.insertionPoint < s.length) {
          token = {type: 'abort'};
          return s;
        }
        token = {type: 'end-tag', value: 'script'};
        p.insertionPoint -= s.length;
        return '';
      });
      if (token) return token;
      var m;
      if ((p.insertionPoint < '</script'.length) &&
          (m = i.s.match (/^<\/([SCRIPTscript]+)/))) {
        var v = m[1].substring (0, p.insertionPoint).toLowerCase ();
        if (v == 'script'.substring (0, p.insertionPoint - '</'.length)) {
          return {type: 'abort'};
        }
      }
      i.s = i.s.replace (/^</,
      function (s) {
        token = {type: 'char', value: s};
        p.insertionPoint -= s.length;
        return '';
      });
      if (token) return token;
      return {type: 'eof'};
    }

    var token;
    i.s = i.s.replace (/^<\/([^>]+)(?:>|$)/, function (s, e) {
      if (p.insertionPoint < s.length ||
          (p.insertionPoint <= s.length &&
           s.substring (s.length - 1, 1) != '>')) {
        token = {type: 'abort'};
        return s;
      }
      token = {type: 'end-tag', value: e.toLowerCase ()};
      p.insertionPoint -= s.length;
      return '';
    });
    if (token) return token;
    i.s = i.s.replace (/^<([^>]+)(?:>|$)/, function (s, e) {
      if (p.insertionPoint < s.length ||
          (p.insertionPoint <= s.length &&
           s.substring (s.length - 1, 1) != '>')) {
        token = {type: 'abort'};
        return s;
      }
      var tagName;
      var attrs = {};
      e = e.replace (/^[\S]+/, function (v) {
        tagName = v.toLowerCase ();
        return '';
      });
      e = e.replace (/^\s*([^\s=]+)\s*(?:=\s*(?:"([^"]*)"|'([^']*)'|([^"']+)))?/,
      function (x, attrName, attrValue1, attrValue2, attrValue3) {
        v = attrValue1 || attrValue2 || attrValue3;
        v = v.replace (/&quot;/g, '"').replace (/&apos;/g, "'")
            .replace (/&amp;/g, '&');
        attrs[attrName.toLowerCase ()] = v;
        return '';
      });
      if (e.length) {
        log ('Broken start tag: "' + e + '"');
      }
      token = {type: 'start-tag', value: tagName, attrs: attrs};
      p.insertionPoint -= s.length;
      return '';
    });
    if (token) return token;
    if (p.insertionPoint <= 0) {
      return {type: 'abort'};
    }
    i.s = i.s.replace (/^[^<]+/, function (s) {
      if (p.insertionPoint < s.length) {
        token = {type: 'char', value: s.substring (0, p.insertionPoint)};
        var ip = p.insertionPoint;
        p.insertionPoint = 0;
        return s.substring (ip, s.length);
      }
      token = {type: 'char', value: s};
      p.insertionPoint -= s.length;
      return '';
    });
    if (token) return token;
    i.s = i.s.replace (/^[\s\S]/, function (s) {
      token = {type: 'char', value: s};
      p.insertionPoint -= s.length;
      return '';
    });
    if (token) return token;
    return {type: 'eof'};
  } // getNextToken

  Parser.prototype.parse = function () {
    logIndentLevel++;
    log ('parse: start');

    while (true) {
      var token = this.getNextToken ();
      log ('token: ' + token.type + ' "' + token.value + '"');

      if (token.type == 'start-tag') {
        if (token.value == 'script') {
          // 1. Create an element for the token in the HTML namespace.
          var el = new JSElement (this.doc, token.value);
          if (token.attrs.async != null) el.async = true;
          if (token.attrs.defer != null) el.defer = true;
          if (token.attrs.src != null) el.src = token.attrs.src;

          // 2. Mark the element as being "parser-inserted".
          el.manakaiParserInserted = true;

          // 3. Switch the tokeniser's content model flag to the CDATA state.
          this.parseMode = 'script';

          // 4.1. Collect all the character tokens.
          while (true) {
            var token = this.getNextToken ();
            log ('token: ' + token.type + ' "' + token.value + '"');

            if (token.type == 'char') {
              // 5. Append a single Text node to the script element node.
              el.manakaiAppendText (token.value);

            // 4.2. Until it returns a token that is not a character token, or
            // until it stops tokenising.
            } else if (token.type == 'eof' ||
                       (token.type == 'end-tag' && token.value == 'script') ||
                       token.type == 'abort') {
              // 6. Switched back to the PCDATA state.
              this.parseMode = 'pcdata';

              // 7.1. If the next token is not an end tag token with ...
              if (token.type != 'end-tag') {
                // 7.2. This is a parse error.
                log ('Parse error: no </' + 'script>');

                // 7.3. Mark the script element as "already executed".
                el.manakaiAlreadyExecuted = true;
              } else {
                // 7.4. Ignore it.
                //
              }
              break;
            }
          }

          // 8.1. If the parser were originally created for the ...
          if (this.fragmentParsingMode) {
            // 8.2. Mark the script element as "already executed" and ...
            el.alreadyExecuted = true;
            continue;
          }

          // 9.1. Let the old insertion point have the same value as the ...
          var oldInsertionPoint = this.insertionPoint;
          // 9.2. Let the insertion point be just before the next input ...
          this.setInsertionPoint (0);

          // 10. Append the new element to the current node.
          this.openElements[this.openElements.length - 1].appendChild (el);

          // 11. Let the insertion point have the value of the old ...

          oldInsertionPoint += this.insertionPoint;
          this.setInsertionPoint (oldInsertionPoint);

          // 12. If there is a script that will execute as soon as ...
          while (this.scriptExecutedWhenParserResumes) {
            // 12.1. If the tree construction stage is being called reentrantly
            if (this.reentrant) {
              log ('parse: abort (reentrance)');
              logIndentLevel--;
              return;

            // 12.2. Otherwise
            } else {
              // 1.
              var script = this.scriptExecutedWhenParserResumes;
              this.scriptExecutedWhenParserResumes = null;

              // 2. Pause until the script has completed loading.
              // 

              // 3. Let the insertion point to just before the next input char.
              this.setInsertionPoint (0);

              // 4. Execute the script.
              executeScript (this.doc, script);

              // 5. Let the insertion point be undefined again.
              this.setInsertionPoint (undefined);

              // 6. If there is once again a script that will execute ...
              //
            }
          }
        } else {
          var el = new JSElement (this.doc, token.value);
          this.openElements[this.openElements.length - 1].appendChild (el);
          this.openElements.push (el);
        }
      } else if (token.type == 'end-tag') {
        if (this.openElements[this.openElements.length - 1].localName ==
            token.value) {
          this.openElements.pop ();
        } else {
          log ('parse error: unmatched end tag: ' + token.value);
        }
      } else if (token.type == 'char') {
        this.openElements[this.openElements.length - 1].manakaiAppendText
            (token.value);
      } else if (token.type == 'eof') {
        break;
      } else if (token.type == 'abort') {
        log ('parse: abort');
        logIndentLevel--;
        return;
      }
    }

    log ('stop parsing');

    // readyState = 'interactive'

    // "When a script completes loading" rules start applying.

    // TODO: Handles "list of scripts that will execute as soon as possible"
    // and "list of scripts that will execute asynchronously"

    // Handle "list of scripts that will execute when the document has finished
    // parsing".
    var list = this.scriptsExecutedAfterParsing;
    while (list.length > 0) {
      // TODO: break unless completed loading

      // Step 1.
      //

      // Step 2. and Step 3.
      log ('Executing a |defer|red script...');
      executeScript (this.doc, list.shift ());

      // Step 4.
    }

    log ('DOMContentLoaded event fired');

    // "delays tha load event" things has completed:
    // readyState = 'complete'
    log ('load event fired');

    logIndentLevel--;
  } // parse

  Parser.prototype.setInsertionPoint = function (ip) {
    if (ip == undefined || ip == null || isNaN (ip)) {
      log ('insertion point: set to undefined');
      this.insertionPoint = undefined;
    } else if (ip == this.in.s.length) {
      log ('insertion point: end of file');
      this.insertionPoint = ip;
    } else {
      log ('insertion point: set to ' + ip +
           ' (before "' + this.in.s.substring (0, 10) + '")');
      this.insertionPoint = ip;
    }
  }; // setInsertionPoint

  function JSDocument (p) {
    this.childNodes = [];
    this._parser = p;
  } // JSDocument

  function JSElement (doc, localName) {
    this.localName = localName;
    this.ownerDocument = doc;
    this.childNodes = [];
  } // JSElement

  JSDocument.prototype.appendChild = JSElement.prototype.appendChild =
  function (e) {
    this.childNodes.push (e);
    e.parentNode = this;

    if (e.localName == 'script') {
      logIndentLevel++;
      log ('Running a script: start');

      var doc = this.ownerDocument || this;
      var p = doc._parser;

      // 1. Script type
      //

      // 2.1. If scripting is disabled
      //
      // 2.2. If the script element was created by an XML ... innerHTML ...
      //
      // 2.3. If the user agent does not support the scripting language ...
      //
      // 2.4. If the script element has its "already executed" flag set
      if (e.manakaiAlreadyExecuted) {
        // 2.5. Abort these steps at this point.
        log ('Running a script: aborted');
        logIndentLevel--;
        return e;
      }

      // 3. Set the element's "already executed" flag.
      e.manakaiAlreadyExecuted = true;

      // 4. If the element has a src attribute, then a load for ...
      // TODO: load an external resource

      // 5. The first of the following options:

      // 5.1. 
      if (/* TODO: If the document is still being parsed && */
          e.defer && !e.async) {
        p.scriptsExecutedAfterParsing.push (e);
        log ('Running a script: aborted (defer)');
      } else if (e.async && e.src != null) {
        // TODO
      } else if (e.async && e.src == null
                 /* && list of scripts that will execute asynchronously is not empty */) {
        // TODO
      } else if (e.src != null && e.manakaiParserInserted) {
        if (p.scriptExecutedWhenParserResumes) {
          log ('Error: There is a script that will execute as soon as the parser resumes.');
        }
        p.scriptExecutedWhenParserResumes = e;
        log ('Running a script: aborted (src)');
      } else if (e.src != null) {
        // TODO
      } else {
        executeScript (doc, e); // even if other scripts are already executing.
      }

      log ('Running a script: end');
      logIndentLevel--;
    }

    return e;
  }; // appendChild

  function executeScript (doc, e) {
    log ('executing a script block: start');

    var s;
    if (e.src != null) {
      s = getExternalScript (e.src);

      // If the load resulted in an error, then ... firing an error event ...
      if (s == null) {
        log ('error event fired at the script element');
        return;
      }

      log ('External script loaded: "' + s + '"');
    } else {
      s = e.text;
    }

    // If the load was successful
    log ('load event fired at the script element');

    if (true) {
    // Scripting is enabled, Document.designMode is disabled,
    // Document is the active document in its browsing context

      parseAndRunScript (doc, s);
    }

    log ('executing a script block: end');
  } // executeScript

  function getExternalScript (uri) {
    if (uri.match (/^javascript:/i)) {
      var m;
      if (m = uri.match (/^javascript:\s*(?:'([^']*)'|"([^"]+)")\s*$/i)) {
        if (m[1]) {
          return m[1];
        } else if (m[2]) {
          return m[2];
        } else {
          return null;
        }
      } else {
        log ('Complex javascript: URI is not supported: <' + uri + '>');
        return null;
      }
    } else {
      log ('URI scheme not supported: <' + uri + '>');
      return null;
    }
  } // getExternalScript

  function parseAndRunScript (doc, s) {
    while (true) {
      var matched = false;
      s = s.replace (/^\s*document\.write\s*\(((?:'[^']*'|"[^"]*")\s*(?:,\s*(?:'[^']*'|"[^"]*"))*)\)\s*;\s*/, function (s, t) {
        matched = true;
        var args = [];
        t.replace (/('[^']*'|"[^"]*")/g, function (s, v) {
          args.push (v.substring (1, v.length - 1));
          return '';
        });
        doc.write.apply (doc, args);
        return '';
      });
      if (s == '') break;
      if (!matched) {
        log ('Script parse error: "' + s + '"');
        break;
      }
    }
  } // parseAndRunScript

  function JSText (data) {
    this.data = data;
  } // JSText

  JSDocument.prototype.manakaiAppendText =
  JSElement.prototype.manakaiAppendText =
  function (s) {
    if (this.childNodes.length > 0 &&
        this.childNodes[this.childNodes.length - 1] instanceof JSText) {
      this.childNodes[this.childNodes.length - 1].data += s;
    } else {
      this.childNodes.push (new JSText (s));
    }
  }; // manakaiAppendText

  JSDocument.prototype.open = function () {
    // Two or fewer arguments

    // Step 1.
    var type = arguments[0] || 'text/html';
    
    // Step 2.
    var replace = arguments[1] == 'replace';

    // Step 3.
    if (this._parser &&
        !this._parser.scriptCreated &&
        this._parser.in.insertionPoint != undefined) {
      log ('document.open () in parsing mode is ignored');
      return this;
    }

    // Step 4.
    log ('onbeforeunload event fired');
    log ('onunload event fired');

    // Step 5.
    if (this._parser) {
      // Discard the parser.
    }

    // Step 6.
    log ('document cleared by document.open ()');
    this.childNodes = [];

    // Step 7.
    this._parser = new Parser (new InputStream (''), this);
    this._parser.scriptCreated = true;

    // Step 8.
    this.manakaiIsHTML = true;

    // Step 9.
    // If not text/html, ...

    // Step 10.
    if (!replace) {
      // History      
    }

    // Step 11.
    this._parser.setInsertionPoint (this._parser.in.s.length);

    // Step 12.
    return this;
  }; // document.open

  JSDocument.prototype.write = function () {
    logIndentLevel++;

    var p = this._parser;

    // 1. If the insertion point is undefined, the open() method must be ...
    if (isNaN (p.insertionPoint) || p.insertionPoint == undefined) {
      this.open ();
      p = this._parser;
    }

    // 2. ... inserted into the input stream just before the insertion point.
    var s = Array.join (arguments, '');
    log ('document.write: insert "' + s + '"' +
         ' before "' + p.in.s.substring (p.insertionPoint, p.insertionPoint + 10) + '"');
    p.in.s = p.in.s.substring (0, p.insertionPoint) + s
        + p.in.s.substring (p.insertionPoint, p.in.s.length);
    p.insertionPoint += s.length;

    // 3. If there is a script that will execute as soon as the parser resumes
    if (p.scriptExecutedAfterParserResumes) {
      log ('document.write: processed later (there is an unprocessed <script src>)');
      logIndentLevel--;
      return;
    }

    // 4. Process the characters that were inserted, ...
    var originalReentrant = p.reentrant;
    p.reentrant = true;
    p.parse ();
    p.reentrant = originalReentrant;
    // TODO: "Abort the processing of any nested invokations of the tokeniser,
    // yielding control back to the caller." (<script> parsing).  Do we need
    // to do something here?

    // 5. Return
    log ('document.write: return');

    logIndentLevel--;
    return;
  }; // document.write

  JSElement.prototype.__defineGetter__ ('text', function () {
    var r = '';
    for (var i = 0; i < this.childNodes.length; i++) {
      if (this.childNodes[i] instanceof JSText) {
        r += this.childNodes[i].data;
      }
    }
    return r;
  });

  function dumpTree (n, indent) {
    var r = '';
    for (var i = 0; i < n.childNodes.length; i++) {
      var node = n.childNodes[i];
      if (node instanceof JSElement) {
        r += '| ' + indent + node.localName + '\n';
        if (node.async) r += '| ' + indent + '  async=""\n';
        if (node.defer) r += '| ' + indent + '  defer=""\n';
        if (node.src) r += '| ' + indent + '  src="' + node.src + '"\n';
        r += dumpTree (node, indent + '  ');
      } else if (node instanceof JSText) {
        r += '| ' + indent + '"' + node.data + '"\n';
      } else {
        r += '| ' + indent + node + '\n';
      }
    }
    return r;
  } // dumpTree
</script>
</head>
<body onload="
  document.sourceElement = document.getElementsByTagName ('textarea')[0];
  document.logElement = document.getElementsByTagName ('output')[0];
  update ();
">
<h1>Live Scripting Parser</h1>

<h2>Markup to test
(<a href=data:, id=permalink rel=bookmark>permalink</a>)</h2>
<p>
<textarea onkeydown=" update () " onchange=" update () " oninput=" update () ">&lt;html>
&lt;head>&lt;/head>&lt;body>
&lt;p>
&lt;script>
document.write ('aaaaaaa&lt;/p>&lt;script>document.write("cccccc");&lt;/', 'script>bbbbbb');
&lt;/script>
&lt;p>
</textarea>

<h2>Log</h2>
<p><output></output>

<!-- TODO: short description -->

<!-- TODO: permalink query -> textarea -->

<!-- TODO: multiple attributes are not supported yet -->

</body>
</html>
1	<!DOCTYPE HTML>
2	<html lang=en>
3	<head>
4	<title>Demo of HTML5 Parsing Algorithm with Scripting Enabled</title>
5	<style>
6	h1, h2 {
7	margin: 0;
8	font-size: 100%;
9	}
10	p, pre {
11	margin: 0;
12	}
13	textarea {
14	width: 100%;
15	-width: 99%;
16	height: 10em;
17	}
18	output {
19	display: block;
20	font-family: monospace;
21	white-space: -moz-pre-wrap;
22	white-space: pre-wrap;
23	}
24	</style>
25	<script>
26	var delayedUpdater = 0;
27
28	function update () {
29	if (delayedUpdater) {
30	clearTimeout (delayedUpdater);
31	delayedUpdater = 0;
32	}
33	delayedUpdater = setTimeout (update2, 100);
34	} // update
35
36	function update2 () {
37	document.logElement.textContent = '';
38	var v = document.sourceElement.value;
39	var p = new Parser (new InputStream (v));
40	var doc = p.doc;
41	p.parse ();
42	log (dumpTree (doc, ''));
43
44	document.links['permalink'].href
45	= location.href + '?s=' + encodeURIComponent (v);
46	} // update2
47
48	var logIndentLevel = 0;
49	function log (s) {
50	for (var i = 0; i < logIndentLevel; i++) {
51	s = ' ' + s;
52	}
53	document.logElement.appendChild (document.createTextNode (s + "\n"));
54	} // log
55
56	function InputStream (s) {
57	this.s = s;
58	} // InputStream
59
60	function Parser (i, doc) {
61	this.parseMode = 'pcdata';
62	if (!doc) {
63	doc = new JSDocument (this);
64	doc.manakaiIsHTML = true;
65	}
66	this.doc = doc;
67	this.openElements = [doc];
68	this.in = i;
69	this.scriptsExecutedAfterParsing = [];
70	} // Parser
71
72	Parser.prototype.getNextToken = function () {
73	var p = this;
74	var i = this.in;
75	if (this.parseMode == 'script') {
76	var token;
77	if (p.insertionPoint <= 0) {
78	return {type: 'abort'};
79	}
80	i.s = i.s.replace (/^([^<]+)/,
81	function (s, t) {
82	if (0 < p.insertionPoint && p.insertionPoint < t.length) {
83	token = {type: 'char', value: t.substring (0, p.insertionPoint)};
84	var ip = p.insertionPoint;
85	p.insertionPoint = 0;
86	return t.substring (ip, t.length);
87	}
88	token = {type: 'char', value: t};
89	p.insertionPoint -= t.length;
90	return '';
91	});
92	if (token) return token;
93	i.s = i.s.replace (/^<\/[Ss][Cc][Rr][Ii][Pp][Tt]>/, function (s) {
94	if (p.insertionPoint < s.length) {
95	token = {type: 'abort'};
96	return s;
97	}
98	token = {type: 'end-tag', value: 'script'};
99	p.insertionPoint -= s.length;
100	return '';
101	});
102	if (token) return token;
103	var m;
104	if ((p.insertionPoint < '</script'.length) &&
105	(m = i.s.match (/^<\/([SCRIPTscript]+)/))) {
106	var v = m[1].substring (0, p.insertionPoint).toLowerCase ();
107	if (v == 'script'.substring (0, p.insertionPoint - '</'.length)) {
108	return {type: 'abort'};
109	}
110	}
111	i.s = i.s.replace (/^</,
112	function (s) {
113	token = {type: 'char', value: s};
114	p.insertionPoint -= s.length;
115	return '';
116	});
117	if (token) return token;
118	return {type: 'eof'};
119	}
120
121	var token;
122	i.s = i.s.replace (/^<\/([^>]+)(?:>\|$)/, function (s, e) {
123	if (p.insertionPoint < s.length \|\|
124	(p.insertionPoint <= s.length &&
125	s.substring (s.length - 1, 1) != '>')) {
126	token = {type: 'abort'};
127	return s;
128	}
129	token = {type: 'end-tag', value: e.toLowerCase ()};
130	p.insertionPoint -= s.length;
131	return '';
132	});
133	if (token) return token;
134	i.s = i.s.replace (/^<([^>]+)(?:>\|$)/, function (s, e) {
135	if (p.insertionPoint < s.length \|\|
136	(p.insertionPoint <= s.length &&
137	s.substring (s.length - 1, 1) != '>')) {
138	token = {type: 'abort'};
139	return s;
140	}
141	var tagName;
142	var attrs = {};
143	e = e.replace (/^[\S]+/, function (v) {
144	tagName = v.toLowerCase ();
145	return '';
146	});
147	e = e.replace (/^\s([^\s=]+)\s(?:=\s(?:"([^"])"\|'([^']*)'\|([^"']+)))?/,
148	function (x, attrName, attrValue1, attrValue2, attrValue3) {
149	v = attrValue1 \|\| attrValue2 \|\| attrValue3;
150	v = v.replace (/"/g, '"').replace (/'/g, "'")
151	.replace (/&/g, '&');
152	attrs[attrName.toLowerCase ()] = v;
153	return '';
154	});
155	if (e.length) {
156	log ('Broken start tag: "' + e + '"');
157	}
158	token = {type: 'start-tag', value: tagName, attrs: attrs};
159	p.insertionPoint -= s.length;
160	return '';
161	});
162	if (token) return token;
163	if (p.insertionPoint <= 0) {
164	return {type: 'abort'};
165	}
166	i.s = i.s.replace (/^[^<]+/, function (s) {
167	if (p.insertionPoint < s.length) {
168	token = {type: 'char', value: s.substring (0, p.insertionPoint)};
169	var ip = p.insertionPoint;
170	p.insertionPoint = 0;
171	return s.substring (ip, s.length);
172	}
173	token = {type: 'char', value: s};
174	p.insertionPoint -= s.length;
175	return '';
176	});
177	if (token) return token;
178	i.s = i.s.replace (/^[\s\S]/, function (s) {
179	token = {type: 'char', value: s};
180	p.insertionPoint -= s.length;
181	return '';
182	});
183	if (token) return token;
184	return {type: 'eof'};
185	} // getNextToken
186
187	Parser.prototype.parse = function () {
188	logIndentLevel++;
189	log ('parse: start');
190
191	while (true) {
192	var token = this.getNextToken ();
193	log ('token: ' + token.type + ' "' + token.value + '"');
194
195	if (token.type == 'start-tag') {
196	if (token.value == 'script') {
197	// 1. Create an element for the token in the HTML namespace.
198	var el = new JSElement (this.doc, token.value);
199	if (token.attrs.async != null) el.async = true;
200	if (token.attrs.defer != null) el.defer = true;
201	if (token.attrs.src != null) el.src = token.attrs.src;
202
203	// 2. Mark the element as being "parser-inserted".
204	el.manakaiParserInserted = true;
205
206	// 3. Switch the tokeniser's content model flag to the CDATA state.
207	this.parseMode = 'script';
208
209	// 4.1. Collect all the character tokens.
210	while (true) {
211	var token = this.getNextToken ();
212	log ('token: ' + token.type + ' "' + token.value + '"');
213
214	if (token.type == 'char') {
215	// 5. Append a single Text node to the script element node.
216	el.manakaiAppendText (token.value);
217
218	// 4.2. Until it returns a token that is not a character token, or
219	// until it stops tokenising.
220	} else if (token.type == 'eof' \|\|
221	(token.type == 'end-tag' && token.value == 'script') \|\|
222	token.type == 'abort') {
223	// 6. Switched back to the PCDATA state.
224	this.parseMode = 'pcdata';
225
226	// 7.1. If the next token is not an end tag token with ...
227	if (token.type != 'end-tag') {
228	// 7.2. This is a parse error.
229	log ('Parse error: no </' + 'script>');
230
231	// 7.3. Mark the script element as "already executed".
232	el.manakaiAlreadyExecuted = true;
233	} else {
234	// 7.4. Ignore it.
235	//
236	}
237	break;
238	}
239	}
240
241	// 8.1. If the parser were originally created for the ...
242	if (this.fragmentParsingMode) {
243	// 8.2. Mark the script element as "already executed" and ...
244	el.alreadyExecuted = true;
245	continue;
246	}
247
248	// 9.1. Let the old insertion point have the same value as the ...
249	var oldInsertionPoint = this.insertionPoint;
250	// 9.2. Let the insertion point be just before the next input ...
251	this.setInsertionPoint (0);
252
253	// 10. Append the new element to the current node.
254	this.openElements[this.openElements.length - 1].appendChild (el);
255
256	// 11. Let the insertion point have the value of the old ...
257
258	oldInsertionPoint += this.insertionPoint;
259	this.setInsertionPoint (oldInsertionPoint);
260
261	// 12. If there is a script that will execute as soon as ...
262	while (this.scriptExecutedWhenParserResumes) {
263	// 12.1. If the tree construction stage is being called reentrantly
264	if (this.reentrant) {
265	log ('parse: abort (reentrance)');
266	logIndentLevel--;
267	return;
268
269	// 12.2. Otherwise
270	} else {
271	// 1.
272	var script = this.scriptExecutedWhenParserResumes;
273	this.scriptExecutedWhenParserResumes = null;
274
275	// 2. Pause until the script has completed loading.
276	//
277
278	// 3. Let the insertion point to just before the next input char.
279	this.setInsertionPoint (0);
280
281	// 4. Execute the script.
282	executeScript (this.doc, script);
283
284	// 5. Let the insertion point be undefined again.
285	this.setInsertionPoint (undefined);
286
287	// 6. If there is once again a script that will execute ...
288	//
289	}
290	}
291	} else {
292	var el = new JSElement (this.doc, token.value);
293	this.openElements[this.openElements.length - 1].appendChild (el);
294	this.openElements.push (el);
295	}
296	} else if (token.type == 'end-tag') {
297	if (this.openElements[this.openElements.length - 1].localName ==
298	token.value) {
299	this.openElements.pop ();
300	} else {
301	log ('parse error: unmatched end tag: ' + token.value);
302	}
303	} else if (token.type == 'char') {
304	this.openElements[this.openElements.length - 1].manakaiAppendText
305	(token.value);
306	} else if (token.type == 'eof') {
307	break;
308	} else if (token.type == 'abort') {
309	log ('parse: abort');
310	logIndentLevel--;
311	return;
312	}
313	}
314
315	log ('stop parsing');
316
317	// readyState = 'interactive'
318
319	// "When a script completes loading" rules start applying.
320
321	// TODO: Handles "list of scripts that will execute as soon as possible"
322	// and "list of scripts that will execute asynchronously"
323
324	// Handle "list of scripts that will execute when the document has finished
325	// parsing".
326	var list = this.scriptsExecutedAfterParsing;
327	while (list.length > 0) {
328	// TODO: break unless completed loading
329
330	// Step 1.
331	//
332
333	// Step 2. and Step 3.
334	log ('Executing a \|defer\|red script...');
335	executeScript (this.doc, list.shift ());
336
337	// Step 4.
338	}
339
340	log ('DOMContentLoaded event fired');
341
342	// "delays tha load event" things has completed:
343	// readyState = 'complete'
344	log ('load event fired');
345
346	logIndentLevel--;
347	} // parse
348
349	Parser.prototype.setInsertionPoint = function (ip) {
350	if (ip == undefined \|\| ip == null \|\| isNaN (ip)) {
351	log ('insertion point: set to undefined');
352	this.insertionPoint = undefined;
353	} else if (ip == this.in.s.length) {
354	log ('insertion point: end of file');
355	this.insertionPoint = ip;
356	} else {
357	log ('insertion point: set to ' + ip +
358	' (before "' + this.in.s.substring (0, 10) + '")');
359	this.insertionPoint = ip;
360	}
361	}; // setInsertionPoint
362
363	function JSDocument (p) {
364	this.childNodes = [];
365	this._parser = p;
366	} // JSDocument
367
368	function JSElement (doc, localName) {
369	this.localName = localName;
370	this.ownerDocument = doc;
371	this.childNodes = [];
372	} // JSElement
373
374	JSDocument.prototype.appendChild = JSElement.prototype.appendChild =
375	function (e) {
376	this.childNodes.push (e);
377	e.parentNode = this;
378
379	if (e.localName == 'script') {
380	logIndentLevel++;
381	log ('Running a script: start');
382
383	var doc = this.ownerDocument \|\| this;
384	var p = doc._parser;
385
386	// 1. Script type
387	//
388
389	// 2.1. If scripting is disabled
390	//
391	// 2.2. If the script element was created by an XML ... innerHTML ...
392	//
393	// 2.3. If the user agent does not support the scripting language ...
394	//
395	// 2.4. If the script element has its "already executed" flag set
396	if (e.manakaiAlreadyExecuted) {
397	// 2.5. Abort these steps at this point.
398	log ('Running a script: aborted');
399	logIndentLevel--;
400	return e;
401	}
402
403	// 3. Set the element's "already executed" flag.
404	e.manakaiAlreadyExecuted = true;
405
406	// 4. If the element has a src attribute, then a load for ...
407	// TODO: load an external resource
408
409	// 5. The first of the following options:
410
411	// 5.1.
412	if (/* TODO: If the document is still being parsed && */
413	e.defer && !e.async) {
414	p.scriptsExecutedAfterParsing.push (e);
415	log ('Running a script: aborted (defer)');
416	} else if (e.async && e.src != null) {
417	// TODO
418	} else if (e.async && e.src == null
419	/* && list of scripts that will execute asynchronously is not empty */) {
420	// TODO
421	} else if (e.src != null && e.manakaiParserInserted) {
422	if (p.scriptExecutedWhenParserResumes) {
423	log ('Error: There is a script that will execute as soon as the parser resumes.');
424	}
425	p.scriptExecutedWhenParserResumes = e;
426	log ('Running a script: aborted (src)');
427	} else if (e.src != null) {
428	// TODO
429	} else {
430	executeScript (doc, e); // even if other scripts are already executing.
431	}
432
433	log ('Running a script: end');
434	logIndentLevel--;
435	}
436
437	return e;
438	}; // appendChild
439
440	function executeScript (doc, e) {
441	log ('executing a script block: start');
442
443	var s;
444	if (e.src != null) {
445	s = getExternalScript (e.src);
446
447	// If the load resulted in an error, then ... firing an error event ...
448	if (s == null) {
449	log ('error event fired at the script element');
450	return;
451	}
452
453	log ('External script loaded: "' + s + '"');
454	} else {
455	s = e.text;
456	}
457
458	// If the load was successful
459	log ('load event fired at the script element');
460
461	if (true) {
462	// Scripting is enabled, Document.designMode is disabled,
463	// Document is the active document in its browsing context
464
465	parseAndRunScript (doc, s);
466	}
467
468	log ('executing a script block: end');
469	} // executeScript
470
471	function getExternalScript (uri) {
472	if (uri.match (/^javascript:/i)) {
473	var m;
474	if (m = uri.match (/^javascript:\s(?:'([^'])'\|"([^"]+)")\s*$/i)) {
475	if (m[1]) {
476	return m[1];
477	} else if (m[2]) {
478	return m[2];
479	} else {
480	return null;
481	}
482	} else {
483	log ('Complex javascript: URI is not supported: <' + uri + '>');
484	return null;
485	}
486	} else {
487	log ('URI scheme not supported: <' + uri + '>');
488	return null;
489	}
490	} // getExternalScript
491
492	function parseAndRunScript (doc, s) {
493	while (true) {
494	var matched = false;
495	s = s.replace (/^\sdocument\.write\s\(((?:'[^']'\|"[^"]")\s(?:,\s(?:'[^']'\|"[^"]")))\)\s;\s*/, function (s, t) {
496	matched = true;
497	var args = [];
498	t.replace (/('[^']'\|"[^"]")/g, function (s, v) {
499	args.push (v.substring (1, v.length - 1));
500	return '';
501	});
502	doc.write.apply (doc, args);
503	return '';
504	});
505	if (s == '') break;
506	if (!matched) {
507	log ('Script parse error: "' + s + '"');
508	break;
509	}
510	}
511	} // parseAndRunScript
512
513	function JSText (data) {
514	this.data = data;
515	} // JSText
516
517	JSDocument.prototype.manakaiAppendText =
518	JSElement.prototype.manakaiAppendText =
519	function (s) {
520	if (this.childNodes.length > 0 &&
521	this.childNodes[this.childNodes.length - 1] instanceof JSText) {
522	this.childNodes[this.childNodes.length - 1].data += s;
523	} else {
524	this.childNodes.push (new JSText (s));
525	}
526	}; // manakaiAppendText
527
528	JSDocument.prototype.open = function () {
529	// Two or fewer arguments
530
531	// Step 1.
532	var type = arguments[0] \|\| 'text/html';
533
534	// Step 2.
535	var replace = arguments[1] == 'replace';
536
537	// Step 3.
538	if (this._parser &&
539	!this._parser.scriptCreated &&
540	this._parser.in.insertionPoint != undefined) {
541	log ('document.open () in parsing mode is ignored');
542	return this;
543	}
544
545	// Step 4.
546	log ('onbeforeunload event fired');
547	log ('onunload event fired');
548
549	// Step 5.
550	if (this._parser) {
551	// Discard the parser.
552	}
553
554	// Step 6.
555	log ('document cleared by document.open ()');
556	this.childNodes = [];
557
558	// Step 7.
559	this._parser = new Parser (new InputStream (''), this);
560	this._parser.scriptCreated = true;
561
562	// Step 8.
563	this.manakaiIsHTML = true;
564
565	// Step 9.
566	// If not text/html, ...
567
568	// Step 10.
569	if (!replace) {
570	// History
571	}
572
573	// Step 11.
574	this._parser.setInsertionPoint (this._parser.in.s.length);
575
576	// Step 12.
577	return this;
578	}; // document.open
579
580	JSDocument.prototype.write = function () {
581	logIndentLevel++;
582
583	var p = this._parser;
584
585	// 1. If the insertion point is undefined, the open() method must be ...
586	if (isNaN (p.insertionPoint) \|\| p.insertionPoint == undefined) {
587	this.open ();
588	p = this._parser;
589	}
590
591	// 2. ... inserted into the input stream just before the insertion point.
592	var s = Array.join (arguments, '');
593	log ('document.write: insert "' + s + '"' +
594	' before "' + p.in.s.substring (p.insertionPoint, p.insertionPoint + 10) + '"');
595	p.in.s = p.in.s.substring (0, p.insertionPoint) + s
596	+ p.in.s.substring (p.insertionPoint, p.in.s.length);
597	p.insertionPoint += s.length;
598
599	// 3. If there is a script that will execute as soon as the parser resumes
600	if (p.scriptExecutedAfterParserResumes) {
601	log ('document.write: processed later (there is an unprocessed <script src>)');
602	logIndentLevel--;
603	return;
604	}
605
606	// 4. Process the characters that were inserted, ...
607	var originalReentrant = p.reentrant;
608	p.reentrant = true;
609	p.parse ();
610	p.reentrant = originalReentrant;
611	// TODO: "Abort the processing of any nested invokations of the tokeniser,
612	// yielding control back to the caller." (<script> parsing). Do we need
613	// to do something here?
614
615	// 5. Return
616	log ('document.write: return');
617
618	logIndentLevel--;
619	return;
620	}; // document.write
621
622	JSElement.prototype.__defineGetter__ ('text', function () {
623	var r = '';
624	for (var i = 0; i < this.childNodes.length; i++) {
625	if (this.childNodes[i] instanceof JSText) {
626	r += this.childNodes[i].data;
627	}
628	}
629	return r;
630	});
631
632	function dumpTree (n, indent) {
633	var r = '';
634	for (var i = 0; i < n.childNodes.length; i++) {
635	var node = n.childNodes[i];
636	if (node instanceof JSElement) {
637	r += '\| ' + indent + node.localName + '\n';
638	if (node.async) r += '\| ' + indent + ' async=""\n';
639	if (node.defer) r += '\| ' + indent + ' defer=""\n';
640	if (node.src) r += '\| ' + indent + ' src="' + node.src + '"\n';
641	r += dumpTree (node, indent + ' ');
642	} else if (node instanceof JSText) {
643	r += '\| ' + indent + '"' + node.data + '"\n';
644	} else {
645	r += '\| ' + indent + node + '\n';
646	}
647	}
648	return r;
649	} // dumpTree
650	</script>
651	</head>
652	<body onload="
653	document.sourceElement = document.getElementsByTagName ('textarea')[0];
654	document.logElement = document.getElementsByTagName ('output')[0];
655	update ();
656	">
657	<h1>Live Scripting Parser</h1>
658
659	<h2>Markup to test
660	(<a href=data:, id=permalink rel=bookmark>permalink</a>)</h2>
661	<p>
662	<textarea onkeydown=" update () " onchange=" update () " oninput=" update () "><html>
663	<head></head><body>
664	<p>
665	<script>
666	document.write ('aaaaaaa</p><script>document.write("cccccc");</', 'script>bbbbbb');
667	</script>
668	<p>
669	</textarea>
670
671	<h2>Log</h2>
672	<p><output></output>
673
674	<!-- TODO: short description -->
675
676	<!-- TODO: permalink query -> textarea -->
677
678	<!-- TODO: multiple attributes are not supported yet -->
679
680	</body>
681	</html>