Annotation of html5/spec-author-view/scripting-1.html, revision 1.6
1.1 mike 1: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
2: <!DOCTYPE html>
1.5 mike 3: <!-- when publishing, change bits marked ZZZ --><html lang="en-US-x-Hixie" class="split chapter"><head><title>4.3 Scripting — HTML5 (Author Edition)</title><script src="link-fixup.js"></script><link href="whatwg.css" rel="stylesheet"><style type="text/css">
1.1 mike 4: pre { margin-left: 2em; white-space: pre-wrap; }
5: h2 { margin: 3em 0 1em 0; }
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41:
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43: img.extra { float: right; }
44: pre.idl { border: solid thin; background: #EEEEEE; color: black; padding: 0.5em 1em; }
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46: pre.css { border: solid thin; background: #FFFFEE; color: black; padding: 0.5em 1em; }
47: pre.css:first-line { color: #AAAA50; }
48: dl.domintro { color: green; margin: 2em 0 2em 2em; padding: 0.5em 1em; border: none; background: #EEFFEE; }
49: hr + dl.domintro, div.impl + dl.domintro { margin-top: 2.5em; margin-bottom: 1.5em; }
50: dl.domintro dt, dl.domintro dt * { color: black; text-decoration: none; }
51: dl.domintro dd { margin: 0.5em 0 1em 2em; padding: 0; }
52: dl.domintro dd p { margin: 0.5em 0; }
53: dl.switch { padding-left: 2em; }
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55: dl.switch > dt:before { content: '\21AA'; padding: 0 0.5em 0 0; display: inline-block; width: 1em; text-align: right; line-height: 0.5em; }
56: dl.triple { padding: 0 0 0 1em; }
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61: .diff-chg, .diff-new { text-decoration: underline; color: green; background: transparent; }
62: a .diff-new { border-bottom: 1px blue solid; }
63:
64: h2 { page-break-before: always; }
65: h1, h2, h3, h4, h5, h6 { page-break-after: avoid; }
66: h1 + h2, hr + h2.no-toc { page-break-before: auto; }
67:
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71: div.head p { margin: 0; }
72: div.head h1 { margin: 0; }
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75: div.head dl { margin: 1em 0; }
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82: .toc, .toc li { list-style: none; }
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91: .category-list li:not(:last-child)::after { content: ', '; }
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171: #configUI p { margin: 0.5em 0; padding: 0.3em; background: #EEEEEE; color: black; border: inset thin; }
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173: #configUI #updateUI, #configUI .loginUI { text-align: center; }
174: #configUI input[type=button] { display: block; margin: auto; }
175: </style><style type="text/css">
176:
177: .applies thead th > * { display: block; }
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184: .matrix { margin-left: 2em; }
185:
186: .dice-example { border-collapse: collapse; border-style: hidden solid solid hidden; border-width: thin; margin-left: 3em; }
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199: #table-example-1 tbody tr:last-child td { padding-bottom: 1.5em; }
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201: #table-example-1 tbody td:first-child::after { content: leader(". "); }
202: #table-example-1 tbody td { padding-left: 2em; padding-right: 2em; }
203: #table-example-1 tbody td:first-child + td { width: 10em; }
204: #table-example-1 tbody td:first-child + td ~ td { width: 2.5em; }
205: #table-example-1 tbody td:first-child + td + td + td ~ td { width: 1.25em; }
206:
207: .apple-table-examples { border: none; border-collapse: separate; border-spacing: 1.5em 0em; width: 40em; margin-left: 3em; }
208: .apple-table-examples * { font-family: "Times", serif; }
209: .apple-table-examples td, .apple-table-examples th { border: none; white-space: nowrap; padding-top: 0; padding-bottom: 0; }
210: .apple-table-examples tbody th:first-child { border-left: none; width: 100%; }
211: .apple-table-examples thead th:first-child ~ th { font-size: smaller; font-weight: bolder; border-bottom: solid 2px; text-align: center; }
212: .apple-table-examples tbody th::after, .apple-table-examples tfoot th::after { content: leader(". ") }
213: .apple-table-examples tbody th, .apple-table-examples tfoot th { font: inherit; text-align: left; }
214: .apple-table-examples td { text-align: right; vertical-align: top; }
215: .apple-table-examples.e1 tbody tr:last-child td { border-bottom: solid 1px; }
216: .apple-table-examples.e1 tbody + tbody tr:last-child td { border-bottom: double 3px; }
217: .apple-table-examples.e2 th[scope=row] { padding-left: 1em; }
218: .apple-table-examples sup { line-height: 0; }
219:
220: </style><link href="data:text/css," rel="stylesheet" title="Complete specification"><link href="data:text/css,.impl%20%7B%20display:%20none;%20%7D" rel="alternate stylesheet" title="Author documentation only"><link href="data:text/css,.impl%20%7B%20background:%20%23FFEEEE;%20%7D" rel="alternate stylesheet" title="Highlight implementation requirements"><link href="data:text/css," id="complete" rel="stylesheet" title="Complete specification"><link href="data:text/css,.impl%20%7B%20display:%20none;%20%7D" id="author" rel="alternate stylesheet" title="Author documentation only"><link href="data:text/css,.impl%20%7B%20background:%20%23FFEEEE;%20%7D" id="highlight" rel="alternate stylesheet" title="Highlight implementation requirements"><script>
221: function getCookie(name) {
222: var params = location.search.substr(1).split("&");
223: for (var index = 0; index < params.length; index++) {
224: if (params[index] == name)
225: return "1";
226: var data = params[index].split("=");
227: if (data[0] == name)
228: return unescape(data[1]);
229: }
230: var cookies = document.cookie.split("; ");
231: for (var index = 0; index < cookies.length; index++) {
232: var data = cookies[index].split("=");
233: if (data[0] == name)
234: return unescape(data[1]);
235: }
236: return null;
237: }
238: function load(script) {
239: var e = document.createElement('script');
240: e.setAttribute('src', 'http://www.whatwg.org/specs/web-apps/current-work/' + script + '?' + encodeURIComponent(location) + '&' + encodeURIComponent(document.referrer));
241: document.body.appendChild(e);
242: }
243: function init() {
244: if (location.search == '?slow-browser')
245: return;
246: var configUI = document.createElement('div');
247: configUI.id = 'configUI';
248: document.body.appendChild(configUI);
249: // load('reviewer.js'); // would need cross-site XHR
250: if (document.getElementById('head'))
251: load('toc.js');
1.6 ! mike 252: load('styler.js');
1.1 mike 253: // load('updater.js'); // would need cross-site XHR
254: load('dfn.js');
255: // load('status.js'); // would need cross-site XHR
256: if (getCookie('profile') == '1')
257: document.getElementsByTagName('h2')[0].textContent += '; load: ' + (new Date() - loadTimer) + 'ms';
258: fixBrokenLink();
259: }
260: </script><link href="http://www.w3.org/StyleSheets/TR/W3C-ED" rel="stylesheet" type="text/css"><link href="semantics.html" title="4 The elements of HTML" rel="prev">
261: <link href="Overview.html#contents" title="Table of contents" rel="index">
262: <link href="sections.html" title="4.4 Sections" rel="next">
263: </head><body onload="fixBrokenLink(); init()"><div class="head" id="head">
264: <p><a href="http://www.w3.org/"><img alt="W3C" height="48" src="http://www.w3.org/Icons/w3c_home" width="72"></a></p>
1.4 mike 265: <h1>HTML5 (Author Edition)</h1>
1.1 mike 266: </div><div>
267: <a href="semantics.html">← 4 The elements of HTML</a> –
268: <a href="Overview.html#contents">Table of contents</a> –
269: <a href="sections.html">4.4 Sections →</a>
270: <ol class="toc"><li><ol><li><a href="scripting-1.html#scripting-1"><span class="secno">4.3 </span>Scripting</a>
271: <ol><li><a href="scripting-1.html#script"><span class="secno">4.3.1 </span>The <code>script</code> element</a>
272: <ol><li><a href="scripting-1.html#scriptingLanguages"><span class="secno">4.3.1.1 </span>Scripting languages</a></li><li><a href="scripting-1.html#restrictions-for-contents-of-script-elements"><span class="secno">4.3.1.2 </span>Restrictions for contents of <code>script</code> elements</a></li><li><a href="scripting-1.html#inline-documentation-for-external-scripts"><span class="secno">4.3.1.3 </span>Inline documentation for external scripts</a></li></ol></li><li><a href="scripting-1.html#the-noscript-element"><span class="secno">4.3.2 </span>The <code>noscript</code> element</a></li></ol></li></ol></li></ol></div>
273:
274: <h3 id="scripting-1"><span class="secno">4.3 </span>Scripting</h3><p class="XXX annotation"><b>Status: </b><i>Last call for comments</i></p><p>Scripts allow authors to add interactivity to their documents.</p><p>Authors are encouraged to use declarative alternatives to
275: scripting where possible, as declarative mechanisms are often more
276: maintainable, and many users disable scripting.</p><div class="example">
277: <p>For example, instead of using script to show or hide a section
278: to show more details, the <code><a href="interactive-elements.html#the-details-element">details</a></code> element could be
279: used.</p>
280: </div><p>Authors are also encouraged to make their applications degrade
281: gracefully in the absence of scripting support.</p><div class="example">
282: <p>For example, if an author provides a link in a table header to
283: dynamically resort the table, the link could also be made to
284: function without scripts by requesting the sorted table from the
285: server.</p>
286: </div><h4 id="script"><span class="secno">4.3.1 </span>The <dfn><code>script</code></dfn> element</h4><p class="XXX annotation"><b>Status: </b><i>Last call for comments</i></p><dl class="element"><dt>Categories</dt>
287: <dd><a href="content-models.html#metadata-content">Metadata content</a>.</dd>
288: <dd><a href="content-models.html#flow-content">Flow content</a>.</dd>
289: <dd><a href="content-models.html#phrasing-content">Phrasing content</a>.</dd>
290: <dt>Contexts in which this element may be used:</dt>
291: <dd>Where <a href="content-models.html#metadata-content">metadata content</a> is expected.</dd>
292: <dd>Where <a href="content-models.html#phrasing-content">phrasing content</a> is expected.</dd>
293: <dt>Content model:</dt>
294: <dd>If there is no <code title="attr-script-src"><a href="#attr-script-src">src</a></code>
295: attribute, depends on the value of the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, but must match
296: <a href="#restrictions-for-contents-of-script-elements">script content restrictions</a>.</dd>
297: <dd>If there <em>is</em> a <code title="attr-script-src"><a href="#attr-script-src">src</a></code>
298: attribute, the element must be either empty or contain only
299: <a href="#inline-documentation-for-external-scripts">script documentation</a> that also matches <a href="#restrictions-for-contents-of-script-elements">script
300: content restrictions</a>.</dd>
301: <dt>Content attributes:</dt>
302: <dd><a href="elements.html#global-attributes">Global attributes</a></dd>
303: <dd><code title="attr-script-src"><a href="#attr-script-src">src</a></code></dd>
304: <dd><code title="attr-script-async"><a href="#attr-script-async">async</a></code></dd>
305: <dd><code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code></dd>
306: <dd><code title="attr-script-type"><a href="#attr-script-type">type</a></code></dd>
307: <dd><code title="attr-script-charset"><a href="#attr-script-charset">charset</a></code></dd>
308: <dt>DOM interface:</dt>
309: <dd>
310: <pre class="idl">interface <dfn id="htmlscriptelement">HTMLScriptElement</dfn> : <a href="elements.html#htmlelement">HTMLElement</a> {
311: attribute DOMString <a href="#dom-script-src" title="dom-script-src">src</a>;
312: attribute boolean <a href="#dom-script-async" title="dom-script-async">async</a>;
313: attribute boolean <a href="#dom-script-defer" title="dom-script-defer">defer</a>;
314: attribute DOMString <a href="#dom-script-type" title="dom-script-type">type</a>;
315: attribute DOMString <a href="#dom-script-charset" title="dom-script-charset">charset</a>;
316: attribute DOMString <a href="#dom-script-text" title="dom-script-text">text</a>;
317: };</pre>
318: </dd>
319: </dl><p>The <code><a href="#script">script</a></code> element allows authors to include dynamic
320: script and data blocks in their documents. The element does not
321: <a href="#represents" title="represents">represent</a> content for the user.</p><p>When used to include dynamic scripts, the scripts may either be
322: embedded inline or may be imported from an external file using the
323: <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute. If the language
324: is not that described by "<code title="">text/javascript</code>",
325: then the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute must
326: be present, as described below.</p><p>When used to include data blocks, the data must be embedded
327: inline, the format of the data must be given using the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, and the <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute must not be
328: specified.</p><p>The <dfn id="attr-script-type" title="attr-script-type"><code>type</code></dfn>
329: attribute gives the language of the script or format of the data. If
330: the attribute is present, its value must be a <a href="infrastructure.html#valid-mime-type">valid MIME
331: type</a>, optionally with parameters. The <code title="">charset</code> parameter must not be specified. (The
332: default, which is used if the attribute is absent, is "<code title="">text/javascript</code>".)</p><p>The <dfn id="attr-script-src" title="attr-script-src"><code>src</code></dfn>
333: attribute, if specified, gives the address of the external script
334: resource to use. The value of the attribute must be a <a href="urls.html#valid-url">valid
335: URL</a> identifying a script resource of the type given by the
336: <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, if the
337: attribute is present, or of the type "<code title="">text/javascript</code>", if the attribute is absent. A
338: resource is a script resource of a given type if that type
339: identifies a scripting language and the resource conforms with the
340: requirements of that language's specification.</p><p>The <dfn id="attr-script-charset" title="attr-script-charset"><code>charset</code></dfn>
341: attribute gives the character encoding of the external script
342: resource. The attribute must not be specified if the <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute is not present. If the
343: attribute is set, its value must be a valid character encoding name,
344: must be an <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a> match for the
345: <a href="infrastructure.html#preferred-mime-name">preferred MIME name</a> for that encoding, and must match
346: the encoding given in the <code title="">charset</code> parameter of
347: the <a href="#content-type" title="Content-Type">Content-Type metadata</a> of the
348: external file, if any. <a href="references.html#refsIANACHARSET">[IANACHARSET]</a></p><p>The <dfn id="attr-script-async" title="attr-script-async"><code>async</code></dfn> and
349: <dfn id="attr-script-defer" title="attr-script-defer"><code>defer</code></dfn> attributes
350: are <a href="common-microsyntaxes.html#boolean-attribute" title="boolean attribute">boolean attributes</a> that
351: indicate how the script should be executed.</p><p>There are three possible modes that can be selected using these
352: attributes. If the <code title="attr-script-async"><a href="#attr-script-async">async</a></code>
353: attribute is present, then the script will be executed
354: asynchronously, as soon as it is available. If the <code title="attr-script-async"><a href="#attr-script-async">async</a></code> attribute is not present but
355: the <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> attribute is
356: present, then the script is executed when the page has finished
357: parsing. If neither attribute is present, then the script is
358: fetched and executed immediately, before the user agent continues
359: parsing the page. The exact processing details for these attributes
360: are described below.</p><p>The <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> attribute may be
361: specified even if the <code title="attr-script-async"><a href="#attr-script-async">async</a></code>
362: attribute is specified, to cause legacy Web browsers that only
363: support <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> (and not <code title="attr-script-async"><a href="#attr-script-async">async</a></code>) to fall back to the <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> behavior instead of the
364: synchronous blocking behavior that is the default.</p><p>If one or both of the <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> and <code title="attr-script-async"><a href="#attr-script-async">async</a></code> attributes are specified, the
365: <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute must also be
366: specified.</p><p>Changing the <code title="attr-script-src"><a href="#attr-script-src">src</a></code>, <code title="attr-script-type"><a href="#attr-script-type">type</a></code>, <code title="attr-script-charset"><a href="#attr-script-charset">charset</a></code>, <code title="attr-script-async"><a href="#attr-script-async">async</a></code>, and <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> attributes dynamically has no
367: direct effect; these attribute are only used when the element is
368: <a href="infrastructure.html#insert-an-element-into-a-document" title="insert an element into a document">inserted into the
369: document</a>.</p><!-- by implication,
370: changes to the base URL also have no effect --><dl class="domintro"><dt><var title="">script</var> . <code title="dom-script-text"><a href="#dom-script-text">text</a></code> [ = <var title="">value</var> ]</dt>
371:
372: <dd>
373:
374: <p>Returns the contents of the element, ignoring child nodes that
375: aren't <a href="infrastructure.html#text-node" title="text node">text nodes</a>.</p>
376:
377: <p>Can be set, to replace the element's children with the given
378: value.</p>
379:
380: </dd>
381:
382: </dl><p class="note">When inserted using the <code title="dom-document-write"><a href="#dom-document-write">document.write()</a></code> method,
383: <code><a href="#script">script</a></code> elements execute (typically synchronously), but
384: when inserted using <code title="dom-innerHTML"><a href="apis-in-html-documents.html#dom-innerhtml">innerHTML</a></code> and <code title="dom-outerHTML"><a href="apis-in-html-documents.html#dom-outerhtml">outerHTML</a></code> attributes, they do not
385: execute at all.</p><div class="example">
386:
387: <p>In this example, two <code><a href="#script">script</a></code> elements are used. One
388: embeds an external script, and the other includes some data.</p>
389:
390: <pre><script src="game-engine.js"></script>
391: <script type="text/x-game-map">
392: ........U.........e
393: o............A....e
394: .....A.....AAA....e
395: .A..AAA...AAAAA...e
396: </script></pre>
397:
398: <p>The data in this case might be used by the script to generate
399: the map of a video game. The data doesn't have to be used that way,
400: though; maybe the map data is actually embedded in other parts of
401: the page's markup, and the data block here is just used by the
402: site's search engine to help users who are looking for particular
403: features in their game maps.</p>
404:
405: </div><div class="example">
406:
407: <p>The following sample shows how a script element can be used to
408: define a function that is then used by other parts of the
409: document. It also shows how a <code><a href="#script">script</a></code> element can be
410: used to invoke script while the document is being parsed, in this
411: case to initialize the form's output.</p>
412:
413: <pre><script>
414: function calculate(form) {
415: var price = 52000;
416: if (form.elements.brakes.checked)
417: price += 1000;
418: if (form.elements.radio.checked)
419: price += 2500;
420: if (form.elements.turbo.checked)
421: price += 5000;
422: if (form.elements.sticker.checked)
423: price += 250;
424: form.elements.result.value = price;
425: }
426: </script>
427: <form name="pricecalc" onsubmit="return false">
428: <fieldset>
429: <legend>Work out the price of your car</legend>
430: <p>Base cost: £52000.</p>
431: <p>Select additional options:</p>
432: <ul>
433: <li><label><input type=checkbox name=brakes> Ceramic brakes (£1000)</label></li>
434: <li><label><input type=checkbox name=radio> Satellite radio (£2500)</label></li>
435: <li><label><input type=checkbox name=turbo> Turbo charger (£5000)</label></li>
436: <li><label><input type=checkbox name=sticker> "XZ" sticker (£250)</label></li>
437: </ul>
438: <p>Total: £<output name=result onformchange="calculate(form)"></output></p>
439: </fieldset>
440: <script>
441: document.forms.pricecalc.dispatchFormChange();
442: </script>
443: </form></pre>
444:
445: </div><h5 id="scriptingLanguages"><span class="secno">4.3.1.1 </span>Scripting languages</h5><p class="XXX annotation"><b>Status: </b><i>Last call for comments</i></p><p>The following lists some <a href="infrastructure.html#mime-type">MIME type</a> strings and the
446: languages to which they refer:</p><dl><dt>"<code>application/ecmascript</code>"</dt>
447: <dt>"<code>application/javascript</code>"</dt>
448: <dt>"<code>application/x-ecmascript</code>"</dt>
449: <dt>"<code>application/x-javascript</code>"</dt>
450: <dt>"<code>text/ecmascript</code>"</dt>
451: <dt>"<code>text/javascript</code>"</dt>
452: <dt>"<code>text/javascript1.0</code>"</dt>
453: <dt>"<code>text/javascript1.1</code>"</dt>
454: <dt>"<code>text/javascript1.2</code>"</dt>
455: <dt>"<code>text/javascript1.3</code>"</dt>
456: <dt>"<code>text/javascript1.4</code>"</dt>
457: <dt>"<code>text/javascript1.5</code>"</dt>
458: <dt>"<code>text/jscript</code>"</dt>
459: <dt>"<code>text/livescript</code>"</dt>
460: <dt>"<code>text/x-ecmascript</code>"</dt>
461: <dt>"<code>text/x-javascript</code>"</dt>
462: <dd>JavaScript. <a href="references.html#refsECMA262">[ECMA262]</a></dd>
463:
464: <dt>"<code>text/javascript;e4x=1</code>"</dt>
465: <dd>JavaScript with ECMAScript for XML. <a href="references.html#refsECMA357">[ECMA357]</a></dd>
466:
467: </dl><h5 id="restrictions-for-contents-of-script-elements"><span class="secno">4.3.1.2 </span><dfn title="script content restrictions">Restrictions for contents of <code>script</code> elements</dfn></h5><p class="XXX annotation"><b>Status: </b><i>Last call for comments</i></p><p>The <code>textContent</code> of a <code><a href="#script">script</a></code> element must match the
468: <code title="">script</code> production in the following ABNF, the
469: character set for which is Unicode. <a href="references.html#refsABNF">[ABNF]</a></p><pre>script = data1 *( escape [ script-start data3 ] "-->" data1 ) [ escape ]
470: escape = "<!--" data2 *( script-start data3 script-end data2 )
471:
472: data1 = <any string that doesn't contain a substring that matches not-data1>
473: not-data1 = <!-- script-end / -->"<!--" <!-- the script-end is redundant here since it would close the element -->
474:
475: data2 = <any string that doesn't contain a substring that matches not-data2>
476: not-data2 = <!-- script-end / -->script-start / "-->" <!-- the script-end is redundant here since it would close the element -->
477:
478: data3 = <any string that doesn't contain a substring that matches not-data3>
479: not-data3 = script-end / "-->"
480:
481: script-start = lt s c r i p t tag-end
482: script-end = lt slash s c r i p t tag-end
483:
484: lt = %x003C ; U+003C LESS-THAN SIGN character (<)
485: slash = %x002F ; U+002F SOLIDUS character (/)
486:
487: s = %x0053 ; U+0053 LATIN CAPITAL LETTER S
488: s =/ %x0073 ; U+0073 LATIN SMALL LETTER S
489: c = %x0043 ; U+0043 LATIN CAPITAL LETTER C
490: c =/ %x0063 ; U+0063 LATIN SMALL LETTER C
491: r = %x0052 ; U+0052 LATIN CAPITAL LETTER R
492: r =/ %x0072 ; U+0072 LATIN SMALL LETTER R
493: i = %x0049 ; U+0049 LATIN CAPITAL LETTER I
494: i =/ %x0069 ; U+0069 LATIN SMALL LETTER I
495: p = %x0050 ; U+0050 LATIN CAPITAL LETTER P
496: p =/ %x0070 ; U+0070 LATIN SMALL LETTER P
497: t = %x0054 ; U+0054 LATIN CAPITAL LETTER T
498: t =/ %x0074 ; U+0074 LATIN SMALL LETTER T
499:
500: tag-end = %x0009 ; U+0009 CHARACTER TABULATION
501: tag-end =/ %x000A ; U+000A LINE FEED (LF)
502: tag-end =/ %x000C ; U+000C FORM FEED (FF)
503: tag-end =/ %x0020 ; U+0020 SPACE
504: tag-end =/ %x002F ; U+002F SOLIDUS (/)
505: tag-end =/ %x003E ; U+003E GREATER-THAN SIGN (>)</pre><p>When a <code><a href="#script">script</a></code> element contains <a href="#inline-documentation-for-external-scripts">script
506: documentation</a>, there are further restrictions on the contents
507: of the element, as described in the section below.</p><h5 id="inline-documentation-for-external-scripts"><span class="secno">4.3.1.3 </span><dfn title="script documentation">Inline documentation for external scripts</dfn></h5><p class="XXX annotation"><b>Status: </b><i>Last call for comments</i></p><p>If a <code><a href="#script">script</a></code> element's <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute is specified, then the
508: contents of the <code><a href="#script">script</a></code> element, if any, must be such
509: that the value of the <code title="dom-script-text"><a href="#dom-script-text">text</a></code> IDL
510: attribute, which is derived from the element's contents, matches the
511: <code title="">documentation</code> production in the following
512: ABNF, the character set for which is Unicode. <a href="references.html#refsABNF">[ABNF]</a></p><pre>documentation = *( *( space / tab / comment ) [ line-comment ] newline )
513: comment = slash star *( not-star / star not-slash ) 1*star slash
514: line-comment = slash slash *not-newline
515:
516: ; characters
517: tab = %x0009 ; U+0009 TAB
518: newline = %x000A ; U+000A LINE FEED (LF)
519: space = %x0020 ; U+0020 SPACE
520: star = %x002A ; U+002A ASTERISK (*)
521: slash = %x002F ; U+002F SOLIDUS (/)
522: not-newline = %x0000-0009 / %x000B-10FFFF
523: ; a Unicode character other than U+000A LINE FEED (LF)
524: not-star = %x0000-0029 / %x002B-10FFFF
525: ; a Unicode character other than U+002A ASTERISK (*)
526: not-slash = %x0000-002E / %x0030-10FFFF
527: ; a Unicode character other than U+002F SOLIDUS (/)</pre><p class="note">This corresponds to putting the contents of the
528: element in JavaScript comments.</p><p class="note">This requirement is in addition to the earlier
529: restrictions on the syntax of contents of <code><a href="#script">script</a></code>
530: elements.</p><div class="example">
531:
532: <p>This allows authors to include documentation, such as license
533: information or API information, inside their documents while still
534: referring to external script files. The syntax is constrained so
535: that authors don't accidentally include what looks like valid
536: script while also providing a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute.</p>
537:
538: <pre><script src="cool-effects.js">
539: // create new instances using:
540: // var e = new Effect();
541: // start the effect using .play, stop using .stop:
542: // e.play();
543: // e.stop();
544: </script></pre>
545:
546: </div><h4 id="the-noscript-element"><span class="secno">4.3.2 </span>The <dfn><code>noscript</code></dfn> element</h4><p class="XXX annotation"><b>Status: </b><i>Last call for comments</i></p><dl class="element"><dt>Categories</dt>
547: <dd><a href="content-models.html#metadata-content">Metadata content</a>.</dd>
548: <dd><a href="content-models.html#flow-content">Flow content</a>.</dd>
549: <dd><a href="content-models.html#phrasing-content">Phrasing content</a>.</dd>
550: <dt>Contexts in which this element may be used:</dt>
551: <dd>In a <code><a href="semantics.html#the-head-element-0">head</a></code> element of an <a href="dom.html#html-documents" title="HTML documents">HTML document</a>, if there are no ancestor <code><a href="#the-noscript-element">noscript</a></code> elements.</dd>
552: <dd>Where <a href="content-models.html#phrasing-content">phrasing content</a> is expected in <a href="dom.html#html-documents">HTML documents</a>, if there are no ancestor <code><a href="#the-noscript-element">noscript</a></code> elements.</dd>
553: <dt>Content model:</dt>
554: <dd>When <a href="#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a>, in a <code><a href="semantics.html#the-head-element-0">head</a></code> element: in any order, zero or more <code><a href="semantics.html#the-link-element">link</a></code> elements, zero or more <code><a href="semantics.html#the-style-element">style</a></code> elements, and zero or more <code><a href="semantics.html#meta">meta</a></code> elements.</dd>
555: <dd>When <a href="#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a>, not in a <code><a href="semantics.html#the-head-element-0">head</a></code> element: <a href="content-models.html#transparent">transparent</a>, but there must be no <code><a href="#the-noscript-element">noscript</a></code> element descendants.</dd>
556: <dd>Otherwise: text that conforms to the requirements given in the prose.</dd>
557: <dt>Content attributes:</dt>
558: <dd><a href="elements.html#global-attributes">Global attributes</a></dd>
559: <dt>DOM interface:</dt>
560: <dd>Uses <code><a href="elements.html#htmlelement">HTMLElement</a></code>.</dd>
561: </dl><p>The <code><a href="#the-noscript-element">noscript</a></code> element <a href="#represents">represents</a> nothing
562: if <a href="#concept-n-script" title="concept-n-script">scripting is enabled</a>, and
563: <a href="#represents">represents</a> its children if <a href="#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a>. It is used
564: to present different markup to user agents that support scripting
565: and those that don't support scripting, by affecting how the
566: document is parsed.</p><p>When used in <a href="dom.html#html-documents">HTML documents</a>, the allowed content
567: model is as follows:</p><dl><dt>In a <code><a href="semantics.html#the-head-element-0">head</a></code> element, if <a href="#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a> for the
568: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
569:
570: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only
571: <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="semantics.html#the-style-element">style</a></code>, and <code><a href="semantics.html#meta">meta</a></code>
572: elements.</p></dd>
573:
574: <dt>In a <code><a href="semantics.html#the-head-element-0">head</a></code> element, if <a href="#concept-n-script" title="concept-n-script">scripting is enabled</a> for the
575: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
576:
577: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only text,
578: except that invoking the <a href="#html-fragment-parsing-algorithm">HTML fragment parsing
579: algorithm</a> <!-- (which disables <script> execution) --> with
580: the <code><a href="#the-noscript-element">noscript</a></code> element as the <var title="">context</var> element and the text contents as the <var title="">input</var> must result in a list of nodes that consists
581: only of <code><a href="semantics.html#the-link-element">link</a></code>, <code><a href="semantics.html#the-style-element">style</a></code>, and
582: <code><a href="semantics.html#meta">meta</a></code> elements that would be conforming if they were
583: children of the <code><a href="#the-noscript-element">noscript</a></code> element, and no <a href="#parse-error" title="parse error">parse errors</a>.</p></dd>
584:
585: <dt>Outside of <code><a href="semantics.html#the-head-element-0">head</a></code> elements, if <a href="#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a> for the
586: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
587:
588: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element's content model is
589: <a href="content-models.html#transparent">transparent</a>, with the additional restriction that a
590: <code><a href="#the-noscript-element">noscript</a></code> element must not have a <code><a href="#the-noscript-element">noscript</a></code>
591: element as an ancestor (that is, <code><a href="#the-noscript-element">noscript</a></code> can't be
592: nested).</p></dd>
593:
594: <dt>Outside of <code><a href="semantics.html#the-head-element-0">head</a></code> elements, if <a href="#concept-n-script" title="concept-n-script">scripting is enabled</a> for the
595: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
596:
597: <dd>
598:
599: <p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only text,
600: except that the text must be such that running the following
601: algorithm results in a conforming document with no
602: <code><a href="#the-noscript-element">noscript</a></code> elements and no <code><a href="#script">script</a></code>
603: elements, and such that no step in the algorithm causes an
604: <a href="#html-parser">HTML parser</a> to flag a <a href="#parse-error">parse error</a>:</p>
605:
606: <ol><li>Remove every <code><a href="#script">script</a></code> element from the
607: document.</li>
608:
609: <li>Make a list of every <code><a href="#the-noscript-element">noscript</a></code> element in the
610: document. For every <code><a href="#the-noscript-element">noscript</a></code> element in that list,
611: perform the following steps:
612:
613: <ol><li>Let the <var title="">parent element</var> be the parent
614: element of the <code><a href="#the-noscript-element">noscript</a></code> element.</li>
615:
616: <li>Take all the children of the <var title="">parent element</var>
617: that come before the <code><a href="#the-noscript-element">noscript</a></code> element, and call these
618: elements <var title="">the before children</var>.</li>
619:
620: <li>Take all the children of the <var title="">parent element</var>
621: that come <em>after</em> the <code><a href="#the-noscript-element">noscript</a></code> element, and
622: call these elements <var title="">the after children</var>.</li>
623:
624: <li>Let <var title="">s</var> be the concatenation of all the
625: <a href="infrastructure.html#text-node">text node</a> children of the <code><a href="#the-noscript-element">noscript</a></code>
626: element.</li>
627:
628: <li>Set the <code title="dom-innerHTML"><a href="apis-in-html-documents.html#dom-innerhtml">innerHTML</a></code>
629: attribute of the <var title="">parent element</var> to the value
630: of <var title="">s</var>. (This, as a side-effect, causes the
631: <code><a href="#the-noscript-element">noscript</a></code> element to be removed from the
632: document.)</li>
633:
634: <li>Insert <var title="">the before children</var> at the start of
635: the <var title="">parent element</var>, preserving their original
636: relative order.</li>
637:
638: <li>Insert <var title="">the after children</var> at the end of the
639: <var title="">parent element</var>, preserving their original
640: relative order.</li>
641:
642: </ol></li>
643:
644: </ol></dd>
645:
646: </dl><p class="note">All these contortions are required because, for
647: historical reasons, the <code><a href="#the-noscript-element">noscript</a></code> element is handled
648: differently by the <a href="#html-parser">HTML parser</a> based on whether <a href="#scripting-flag" title="scripting flag">scripting was enabled or not</a> when the
649: parser was invoked.</p><p>The <code><a href="#the-noscript-element">noscript</a></code> element must not be used in <a href="dom.html#xml-documents">XML
650: documents</a>.</p><p class="note"><strong>The <code><a href="#the-noscript-element">noscript</a></code> element is only
651: effective in <a href="syntax.html#syntax">the HTML syntax</a>, it has no effect in
652: <a href="the-xhtml-syntax.html#the-xhtml-syntax">the XHTML syntax</a>.</strong></p><div class="example">
653:
654: <p>In the following example, a <code><a href="#the-noscript-element">noscript</a></code> element is
655: used to provide fallback for a script.</p>
656:
657: <pre><form action="calcSquare.php">
658: <p>
659: <label for=x>Number</label>:
660: <input id="x" name="x" type="number">
661: </p>
662: <script>
663: var x = document.getElementById('x');
664: var output = document.createElement('p');
665: output.textContent = 'Type a number; it will be squared right then!';
666: x.form.appendChild(output);
667: x.form.onsubmit = function () { return false; }
668: x.oninput = function () {
669: var v = x.valueAsNumber;
670: output.textContent = v + ' squared is ' + v * v;
671: };
672: </script>
673: <noscript>
674: <input type=submit value="Calculate Square">
675: </noscript>
676: </form></pre>
677:
678: <p>When script is disabled, a button appears to do the calculation
679: on the server side. When script is enabled, the value is computed
680: on-the-fly instead.</p>
681:
682: <p>The <code><a href="#the-noscript-element">noscript</a></code> element is a blunt
683: instrument. Sometimes, scripts might be enabled, but for some
684: reason the page's script might fail. For this reason, it's
685: generally better to avoid using <code><a href="#the-noscript-element">noscript</a></code>, and to
686: instead design the script to change the page from being a
687: scriptless page to a scripted page on the fly, as in the next
688: example:</p>
689:
690: <pre><form action="calcSquare.php">
691: <p>
692: <label for=x>Number</label>:
693: <input id="x" name="x" type="number">
694: </p>
695: <strong><input id="submit" type=submit value="Calculate Square"></strong>
696: <script>
697: var x = document.getElementById('x');
698: var output = document.createElement('p');
699: output.textContent = 'Type a number; it will be squared right then!';
700: x.form.appendChild(output);
701: x.form.onsubmit = function () { return false; }
702: x.oninput = function () {
703: var v = x.valueAsNumber;
704: output.textContent = v + ' squared is ' + v * v;
705: };
706: <strong> var submit = document.getElementById('submit');
707: submit.parentNode.removeChild(submit);</strong>
708: </script>
709: </form></pre>
710:
711: <p>The above technique is also useful in XHTML, since
712: <code><a href="#the-noscript-element">noscript</a></code> is not supported in <a href="the-xhtml-syntax.html#the-xhtml-syntax">the XHTML
713: syntax</a>.</p>
714:
715: </div></body></html>
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