Annotation of html5/spec-author-view/scripting-1.html, revision 1.14
1.9 mike 1: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
2: <!DOCTYPE html>
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">
4: pre { margin-left: 2em; white-space: pre-wrap; }
5: h2 { margin: 3em 0 1em 0; }
6: h3 { margin: 2.5em 0 1em 0; }
7: h4 { margin: 2.5em 0 0.75em 0; }
8: h5, h6 { margin: 2.5em 0 1em; }
9: h1 + h2, h1 + h2 + h2 { margin: 0.75em 0 0.75em; }
10: h2 + h3, h3 + h4, h4 + h5, h5 + h6 { margin-top: 0.5em; }
11: p { margin: 1em 0; }
12: hr:not(.top) { display: block; background: none; border: none; padding: 0; margin: 2em 0; height: auto; }
13: dl, dd { margin-top: 0; margin-bottom: 0; }
14: dt { margin-top: 0.75em; margin-bottom: 0.25em; clear: left; }
15: dt + dt { margin-top: 0; }
16: dd dt { margin-top: 0.25em; margin-bottom: 0; }
17: dd p { margin-top: 0; }
18: dd dl + p { margin-top: 1em; }
19: dd table + p { margin-top: 1em; }
20: p + * > li, dd li { margin: 1em 0; }
21: dt, dfn { font-weight: bold; font-style: normal; }
22: dt dfn { font-style: italic; }
23: pre, code { font-size: inherit; font-family: monospace; font-variant: normal; }
24: pre strong { color: black; font: inherit; font-weight: bold; background: yellow; }
25: pre em { font-weight: bolder; font-style: normal; }
26: @media screen { code { color: orangered; } code :link, code :visited { color: inherit; } }
27: var sub { vertical-align: bottom; font-size: smaller; position: relative; top: 0.1em; }
28: table { border-collapse: collapse; border-style: hidden hidden none hidden; }
29: table thead { border-bottom: solid; }
30: table tbody th:first-child { border-left: solid; }
31: table tbody th { text-align: left; }
32: table td, table th { border-left: solid; border-right: solid; border-bottom: solid thin; vertical-align: top; padding: 0.2em; }
33: blockquote { margin: 0 0 0 2em; border: 0; padding: 0; font-style: italic; }
34:
35: .bad, .bad *:not(.XXX) { color: gray; border-color: gray; background: transparent; }
36: .matrix, .matrix td { border: none; text-align: right; }
37: .matrix { margin-left: 2em; }
38: .dice-example { border-collapse: collapse; border-style: hidden solid solid hidden; border-width: thin; margin-left: 3em; }
39: .dice-example caption { width: 30em; font-size: smaller; font-style: italic; padding: 0.75em 0; text-align: left; }
40: .dice-example td, .dice-example th { border: solid thin; width: 1.35em; height: 1.05em; text-align: center; padding: 0; }
41:
42: .toc dfn, h1 dfn, h2 dfn, h3 dfn, h4 dfn, h5 dfn, h6 dfn { font: inherit; }
43: img.extra { float: right; }
44: pre.idl { border: solid thin; background: #EEEEEE; color: black; padding: 0.5em 1em; }
45: pre.idl :link, pre.idl :visited { color: inherit; background: transparent; }
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; }
54: dl.switch > dt { text-indent: -1.5em; }
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; }
57: dl.triple dt, dl.triple dd { margin: 0; display: inline }
58: dl.triple dt:after { content: ':'; }
59: dl.triple dd:after { content: '\A'; white-space: pre; }
60: .diff-old { text-decoration: line-through; color: silver; background: transparent; }
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:
68: p > span:not([title=""]):not([class="XXX"]):not([class="impl"]), li > span:not([title=""]):not([class="XXX"]):not([class="impl"]) { border-bottom: solid #9999CC; }
69:
70: div.head { margin: 0 0 1em; padding: 1em 0 0 0; }
71: div.head p { margin: 0; }
72: div.head h1 { margin: 0; }
73: div.head .logo { float: right; margin: 0 1em; }
74: div.head .logo img { border: none } /* remove border from top image */
75: div.head dl { margin: 1em 0; }
76: div.head p.copyright, div.head p.alt { font-size: x-small; font-style: oblique; margin: 0; }
77:
78: body > .toc > li { margin-top: 1em; margin-bottom: 1em; }
79: body > .toc.brief > li { margin-top: 0.35em; margin-bottom: 0.35em; }
80: body > .toc > li > * { margin-bottom: 0.5em; }
81: body > .toc > li > * > li > * { margin-bottom: 0.25em; }
82: .toc, .toc li { list-style: none; }
83:
84: .brief { margin-top: 1em; margin-bottom: 1em; line-height: 1.1; }
85: .brief li { margin: 0; padding: 0; }
86: .brief li p { margin: 0; padding: 0; }
87:
88: .category-list { margin-top: -0.75em; margin-bottom: 1em; line-height: 1.5; }
89: .category-list::before { content: '\21D2\A0'; font-size: 1.2em; font-weight: 900; }
90: .category-list li { display: inline; }
91: .category-list li:not(:last-child)::after { content: ', '; }
92: .category-list li > span, .category-list li > a { text-transform: lowercase; }
93: .category-list li * { text-transform: none; } /* don't affect <code> nested in <a> */
94:
95: .XXX { color: #E50000; background: white; border: solid red; padding: 0.5em; margin: 1em 0; }
96: .XXX > :first-child { margin-top: 0; }
97: p .XXX { line-height: 3em; }
98: .annotation { border: solid thin black; background: #0C479D; color: white; position: relative; margin: 8px 0 20px 0; }
99: .annotation:before { position: absolute; left: 0; top: 0; width: 100%; height: 100%; margin: 6px -6px -6px 6px; background: #333333; z-index: -1; content: ''; }
100: .annotation :link, .annotation :visited { color: inherit; }
101: .annotation :link:hover, .annotation :visited:hover { background: transparent; }
102: .annotation span { border: none ! important; }
103: .note { color: green; background: transparent; font-family: sans-serif; }
104: .warning { color: red; background: transparent; }
105: .note, .warning { font-weight: bolder; font-style: italic; }
106: p.note, div.note { padding: 0.5em 2em; }
107: span.note { padding: 0 2em; }
108: .note p:first-child, .warning p:first-child { margin-top: 0; }
109: .note p:last-child, .warning p:last-child { margin-bottom: 0; }
110: .warning:before { font-style: normal; }
111: p.note:before { content: 'Note: '; }
112: p.warning:before { content: '\26A0 Warning! '; }
113:
114: .bookkeeping:before { display: block; content: 'Bookkeeping details'; font-weight: bolder; font-style: italic; }
115: .bookkeeping { font-size: 0.8em; margin: 2em 0; }
116: .bookkeeping p { margin: 0.5em 2em; display: list-item; list-style: square; }
117:
118: h4 { position: relative; z-index: 3; }
119: h4 + .element, h4 + div + .element { margin-top: -2.5em; padding-top: 2em; }
120: .element {
121: background: #EEEEFF;
122: color: black;
123: margin: 0 0 1em 0.15em;
124: padding: 0 1em 0.25em 0.75em;
125: border-left: solid #9999FF 0.25em;
126: position: relative;
127: z-index: 1;
128: }
129: .element:before {
130: position: absolute;
131: z-index: 2;
132: top: 0;
133: left: -1.15em;
134: height: 2em;
135: width: 0.9em;
136: background: #EEEEFF;
137: content: ' ';
138: border-style: none none solid solid;
139: border-color: #9999FF;
140: border-width: 0.25em;
141: }
142:
143: .example { display: block; color: #222222; background: #FCFCFC; border-left: double; margin-left: 2em; padding-left: 1em; }
144: td > .example:only-child { margin: 0 0 0 0.1em; }
145:
146: .tall-and-narrow {
147: font-size: 0.6em;
148: column-width: 25em;
149: column-gap: 1em;
150: -moz-column-width: 25em;
151: -moz-column-gap: 1em;
152: -webkit-column-width: 25em;
153: -webkit-column-gap: 1em;
154: }
155:
156: ul.domTree, ul.domTree ul { padding: 0 0 0 1em; margin: 0; }
157: ul.domTree li { padding: 0; margin: 0; list-style: none; position: relative; }
158: ul.domTree li li { list-style: none; }
159: ul.domTree li:first-child::before { position: absolute; top: 0; height: 0.6em; left: -0.75em; width: 0.5em; border-style: none none solid solid; content: ''; border-width: 0.1em; }
160: ul.domTree li:not(:last-child)::after { position: absolute; top: 0; bottom: -0.6em; left: -0.75em; width: 0.5em; border-style: none none solid solid; content: ''; border-width: 0.1em; }
161: ul.domTree span { font-style: italic; font-family: serif; }
162: ul.domTree .t1 code { color: purple; font-weight: bold; }
163: ul.domTree .t2 { font-style: normal; font-family: monospace; }
164: ul.domTree .t2 .name { color: black; font-weight: bold; }
165: ul.domTree .t2 .value { color: blue; font-weight: normal; }
166: ul.domTree .t3 code, .domTree .t4 code, .domTree .t5 code { color: gray; }
167: ul.domTree .t7 code, .domTree .t8 code { color: green; }
168: ul.domTree .t10 code { color: teal; }
169:
1.13 mike 170: body.dfnEnabled dfn { cursor: pointer; }
171: .dfnPanel {
172: display: inline;
173: position: absolute;
174: z-index: 10;
175: height: auto;
176: width: auto;
177: padding: 0.5em 0.75em;
178: font: small sans-serif, Droid Sans Fallback;
179: background: #DDDDDD;
180: color: black;
181: border: outset 0.2em;
182: }
183: .dfnPanel * { margin: 0; padding: 0; font: inherit; text-indent: 0; }
184: .dfnPanel :link, .dfnPanel :visited { color: black; }
185: .dfnPanel p { font-weight: bolder; }
186: .dfnPanel * + p { margin-top: 0.25em; }
187: .dfnPanel li { list-style-position: inside; }
188:
1.9 mike 189: #configUI { position: absolute; z-index: 20; top: 10em; right: 1em; width: 11em; font-size: small; }
190: #configUI p { margin: 0.5em 0; padding: 0.3em; background: #EEEEEE; color: black; border: inset thin; }
191: #configUI p label { display: block; }
192: #configUI #updateUI, #configUI .loginUI { text-align: center; }
193: #configUI input[type=button] { display: block; margin: auto; }
194: </style><style type="text/css">
195:
196: .applies thead th > * { display: block; }
197: .applies thead code { display: block; }
198: .applies tbody th { whitespace: nowrap; }
199: .applies td { text-align: center; }
200: .applies .yes { background: yellow; }
201:
202: .matrix, .matrix td { border: none; text-align: right; }
203: .matrix { margin-left: 2em; }
204:
205: .dice-example { border-collapse: collapse; border-style: hidden solid solid hidden; border-width: thin; margin-left: 3em; }
206: .dice-example caption { width: 30em; font-size: smaller; font-style: italic; padding: 0.75em 0; text-align: left; }
207: .dice-example td, .dice-example th { border: solid thin; width: 1.35em; height: 1.05em; text-align: center; padding: 0; }
208:
209: #table-example-1 { border: solid thin; border-collapse: collapse; margin-left: 3em; }
210: #table-example-1 * { font-family: "Essays1743", serif; line-height: 1.01em; }
211: #table-example-1 caption { padding-bottom: 0.5em; }
212: #table-example-1 thead, #table-example-1 tbody { border: none; }
213: #table-example-1 th, #table-example-1 td { border: solid thin; }
214: #table-example-1 th { font-weight: normal; }
215: #table-example-1 td { border-style: none solid; vertical-align: top; }
216: #table-example-1 th { padding: 0.5em; vertical-align: middle; text-align: center; }
217: #table-example-1 tbody tr:first-child td { padding-top: 0.5em; }
218: #table-example-1 tbody tr:last-child td { padding-bottom: 1.5em; }
219: #table-example-1 tbody td:first-child { padding-left: 2.5em; padding-right: 0; width: 9em; }
220: #table-example-1 tbody td:first-child::after { content: leader(". "); }
221: #table-example-1 tbody td { padding-left: 2em; padding-right: 2em; }
222: #table-example-1 tbody td:first-child + td { width: 10em; }
223: #table-example-1 tbody td:first-child + td ~ td { width: 2.5em; }
224: #table-example-1 tbody td:first-child + td + td + td ~ td { width: 1.25em; }
225:
226: .apple-table-examples { border: none; border-collapse: separate; border-spacing: 1.5em 0em; width: 40em; margin-left: 3em; }
227: .apple-table-examples * { font-family: "Times", serif; }
228: .apple-table-examples td, .apple-table-examples th { border: none; white-space: nowrap; padding-top: 0; padding-bottom: 0; }
229: .apple-table-examples tbody th:first-child { border-left: none; width: 100%; }
230: .apple-table-examples thead th:first-child ~ th { font-size: smaller; font-weight: bolder; border-bottom: solid 2px; text-align: center; }
231: .apple-table-examples tbody th::after, .apple-table-examples tfoot th::after { content: leader(". ") }
232: .apple-table-examples tbody th, .apple-table-examples tfoot th { font: inherit; text-align: left; }
233: .apple-table-examples td { text-align: right; vertical-align: top; }
234: .apple-table-examples.e1 tbody tr:last-child td { border-bottom: solid 1px; }
1.11 mike 235: .apple-table-examples.e1 tbody + tbody tr:last-child td { border-bottom: double 3px; }
236: .apple-table-examples.e2 th[scope=row] { padding-left: 1em; }
237: .apple-table-examples sup { line-height: 0; }
238:
1.12 mike 239: .details-example img { vertical-align: top; }
240:
241: </style><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 type="text/javascript">
1.11 mike 242: function getCookie(name) {
243: var params = location.search.substr(1).split("&");
244: for (var index = 0; index < params.length; index++) {
245: if (params[index] == name)
246: return "1";
247: var data = params[index].split("=");
248: if (data[0] == name)
249: return unescape(data[1]);
250: }
251: var cookies = document.cookie.split("; ");
252: for (var index = 0; index < cookies.length; index++) {
253: var data = cookies[index].split("=");
254: if (data[0] == name)
255: return unescape(data[1]);
256: }
257: return null;
258: }
259: function load(script) {
260: var e = document.createElement('script');
261: e.setAttribute('src', 'http://www.whatwg.org/specs/web-apps/current-work/' + script + '?' + encodeURIComponent(location) + '&' + encodeURIComponent(document.referrer));
262: document.body.appendChild(e);
263: }
264: function init() {
265: if (location.search == '?slow-browser')
266: return;
267: var configUI = document.createElement('div');
268: configUI.id = 'configUI';
269: document.body.appendChild(configUI);
270: // load('reviewer.js'); // would need cross-site XHR
271: if (document.getElementById('head'))
272: load('toc.js');
273:
274: // load('updater.js'); // would need cross-site XHR
1.12 mike 275: load('dfn.js'); // doesn't support split-out specs, but, oh well.
1.11 mike 276: // load('status.js'); // would need cross-site XHR
277: if (getCookie('profile') == '1')
278: document.getElementsByTagName('h2')[0].textContent += '; load: ' + (new Date() - loadTimer) + 'ms';
279: fixBrokenLink();
280: }
281: </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">
282: <link href="Overview.html#contents" title="Table of contents" rel="index">
283: <link href="sections.html" title="4.4 Sections" rel="next">
284: </head><body onload="fixBrokenLink(); init()"><div class="head" id="head">
285: <p><a href="http://www.w3.org/"><img alt="W3C" height="48" src="http://www.w3.org/Icons/w3c_home" width="72"></a></p>
286: <h1>HTML5 (Author Edition)</h1>
287: </div><div>
288: <a href="semantics.html">← 4 The elements of HTML</a> –
289: <a href="Overview.html#contents">Table of contents</a> –
290: <a href="sections.html">4.4 Sections →</a>
291: <ol class="toc"><li><ol><li><a href="scripting-1.html#scripting-1"><span class="secno">4.3 </span>Scripting</a>
292: <ol><li><a href="scripting-1.html#script"><span class="secno">4.3.1 </span>The <code>script</code> element</a>
293: <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>
294:
295: <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
296: scripting where possible, as declarative mechanisms are often more
297: maintainable, and many users disable scripting.</p><div class="example">
298: <p>For example, instead of using script to show or hide a section
299: to show more details, the <code><a href="interactive-elements.html#the-details-element">details</a></code> element could be
300: used.</p>
301: </div><p>Authors are also encouraged to make their applications degrade
302: gracefully in the absence of scripting support.</p><div class="example">
303: <p>For example, if an author provides a link in a table header to
304: dynamically resort the table, the link could also be made to
305: function without scripts by requesting the sorted table from the
306: server.</p>
307: </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>
308: <dd><a href="content-models.html#metadata-content">Metadata content</a>.</dd>
309: <dd><a href="content-models.html#flow-content">Flow content</a>.</dd>
310: <dd><a href="content-models.html#phrasing-content">Phrasing content</a>.</dd>
311: <dt>Contexts in which this element may be used:</dt>
312: <dd>Where <a href="content-models.html#metadata-content">metadata content</a> is expected.</dd>
313: <dd>Where <a href="content-models.html#phrasing-content">phrasing content</a> is expected.</dd>
314: <dt>Content model:</dt>
315: <dd>If there is no <code title="attr-script-src"><a href="#attr-script-src">src</a></code>
316: attribute, depends on the value of the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, but must match
317: <a href="#restrictions-for-contents-of-script-elements">script content restrictions</a>.</dd>
318: <dd>If there <em>is</em> a <code title="attr-script-src"><a href="#attr-script-src">src</a></code>
319: attribute, the element must be either empty or contain only
320: <a href="#inline-documentation-for-external-scripts">script documentation</a> that also matches <a href="#restrictions-for-contents-of-script-elements">script
321: content restrictions</a>.</dd>
322: <dt>Content attributes:</dt>
323: <dd><a href="elements.html#global-attributes">Global attributes</a></dd>
324: <dd><code title="attr-script-src"><a href="#attr-script-src">src</a></code></dd>
325: <dd><code title="attr-script-async"><a href="#attr-script-async">async</a></code></dd>
326: <dd><code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code></dd>
327: <dd><code title="attr-script-type"><a href="#attr-script-type">type</a></code></dd>
328: <dd><code title="attr-script-charset"><a href="#attr-script-charset">charset</a></code></dd>
329: <dt>DOM interface:</dt>
330: <dd>
331: <pre class="idl">interface <dfn id="htmlscriptelement">HTMLScriptElement</dfn> : <a href="elements.html#htmlelement">HTMLElement</a> {
332: attribute DOMString <a href="#dom-script-src" title="dom-script-src">src</a>;
333: attribute boolean <a href="#dom-script-async" title="dom-script-async">async</a>;
334: attribute boolean <a href="#dom-script-defer" title="dom-script-defer">defer</a>;
335: attribute DOMString <a href="#dom-script-type" title="dom-script-type">type</a>;
336: attribute DOMString <a href="#dom-script-charset" title="dom-script-charset">charset</a>;
337: attribute DOMString <a href="#dom-script-text" title="dom-script-text">text</a>;
338: };</pre>
339: </dd>
340: </dl><p>The <code><a href="#script">script</a></code> element allows authors to include dynamic
341: script and data blocks in their documents. The element does not
342: <a href="#represents" title="represents">represent</a> content for the user.</p><p>When used to include dynamic scripts, the scripts may either be
343: embedded inline or may be imported from an external file using the
344: <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute. If the language
345: is not that described by "<code title="">text/javascript</code>",
346: then the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute must
347: be present, as described below.</p><p>When used to include data blocks, the data must be embedded
348: 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
349: specified.</p><p>The <dfn id="attr-script-type" title="attr-script-type"><code>type</code></dfn>
350: attribute gives the language of the script or format of the data. If
351: the attribute is present, its value must be a <a href="infrastructure.html#valid-mime-type">valid MIME
1.12 mike 352: type</a>. The <code title="">charset</code> parameter must not be
1.14 ! mike 353: specified. The default, which is used if the attribute is absent,
! 354: is "<code title="">text/javascript</code>".</p><p>The <dfn id="attr-script-src" title="attr-script-src"><code>src</code></dfn>
1.11 mike 355: attribute, if specified, gives the address of the external script
356: resource to use. The value of the attribute must be a <a href="urls.html#valid-url">valid
357: URL</a> identifying a script resource of the type given by the
358: <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, if the
359: attribute is present, or of the type "<code title="">text/javascript</code>", if the attribute is absent. A
360: resource is a script resource of a given type if that type
361: identifies a scripting language and the resource conforms with the
362: requirements of that language's specification.</p><p>The <dfn id="attr-script-charset" title="attr-script-charset"><code>charset</code></dfn>
363: attribute gives the character encoding of the external script
364: 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
365: attribute is set, its value must be a valid character encoding name,
366: must be an <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a> match for the
367: <a href="infrastructure.html#preferred-mime-name">preferred MIME name</a> for that encoding, and must match
368: the encoding given in the <code title="">charset</code> parameter of
369: the <a href="#content-type" title="Content-Type">Content-Type metadata</a> of the
370: 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
371: <dfn id="attr-script-defer" title="attr-script-defer"><code>defer</code></dfn> attributes
372: are <a href="common-microsyntaxes.html#boolean-attribute" title="boolean attribute">boolean attributes</a> that
373: indicate how the script should be executed.</p><p>There are three possible modes that can be selected using these
374: attributes. If the <code title="attr-script-async"><a href="#attr-script-async">async</a></code>
375: attribute is present, then the script will be executed
376: 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
377: the <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> attribute is
378: present, then the script is executed when the page has finished
379: parsing. If neither attribute is present, then the script is
380: fetched and executed immediately, before the user agent continues
381: parsing the page. The exact processing details for these attributes
382: are described below.</p><p>The <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> attribute may be
383: specified even if the <code title="attr-script-async"><a href="#attr-script-async">async</a></code>
384: attribute is specified, to cause legacy Web browsers that only
385: 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
386: 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
387: <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute must also be
388: 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
1.12 mike 389: direct effect; these attribute are only used at specific times
390: described below.</p><!-- by implication, changes to the base URL
391: 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>
1.11 mike 392:
393: <dd>
394:
395: <p>Returns the contents of the element, ignoring child nodes that
396: aren't <a href="infrastructure.html#text-node" title="text node">text nodes</a>.</p>
397:
398: <p>Can be set, to replace the element's children with the given
399: value.</p>
400:
401: </dd>
402:
403: </dl><p class="note">When inserted using the <code title="dom-document-write"><a href="#dom-document-write">document.write()</a></code> method,
404: <code><a href="#script">script</a></code> elements execute (typically synchronously), but
405: 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
406: execute at all.</p><div class="example">
407:
408: <p>In this example, two <code><a href="#script">script</a></code> elements are used. One
409: embeds an external script, and the other includes some data.</p>
410:
411: <pre><script src="game-engine.js"></script>
412: <script type="text/x-game-map">
413: ........U.........e
414: o............A....e
415: .....A.....AAA....e
416: .A..AAA...AAAAA...e
417: </script></pre>
418:
419: <p>The data in this case might be used by the script to generate
420: the map of a video game. The data doesn't have to be used that way,
421: though; maybe the map data is actually embedded in other parts of
422: the page's markup, and the data block here is just used by the
423: site's search engine to help users who are looking for particular
424: features in their game maps.</p>
425:
426: </div><div class="example">
427:
428: <p>The following sample shows how a script element can be used to
429: define a function that is then used by other parts of the
430: document. It also shows how a <code><a href="#script">script</a></code> element can be
431: used to invoke script while the document is being parsed, in this
432: case to initialize the form's output.</p>
433:
434: <pre><script>
435: function calculate(form) {
436: var price = 52000;
437: if (form.elements.brakes.checked)
438: price += 1000;
439: if (form.elements.radio.checked)
440: price += 2500;
441: if (form.elements.turbo.checked)
442: price += 5000;
443: if (form.elements.sticker.checked)
444: price += 250;
445: form.elements.result.value = price;
446: }
447: </script>
448: <form name="pricecalc" onsubmit="return false">
449: <fieldset>
450: <legend>Work out the price of your car</legend>
451: <p>Base cost: £52000.</p>
452: <p>Select additional options:</p>
453: <ul>
454: <li><label><input type=checkbox name=brakes> Ceramic brakes (£1000)</label></li>
455: <li><label><input type=checkbox name=radio> Satellite radio (£2500)</label></li>
456: <li><label><input type=checkbox name=turbo> Turbo charger (£5000)</label></li>
457: <li><label><input type=checkbox name=sticker> "XZ" sticker (£250)</label></li>
458: </ul>
459: <p>Total: £<output name=result onformchange="calculate(form)"></output></p>
460: </fieldset>
461: <script>
462: document.forms.pricecalc.dispatchFormChange();
463: </script>
464: </form></pre>
465:
466: </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
467: languages to which they refer:</p><dl><dt>"<code>application/ecmascript</code>"</dt>
468: <dt>"<code>application/javascript</code>"</dt>
469: <dt>"<code>application/x-ecmascript</code>"</dt>
470: <dt>"<code>application/x-javascript</code>"</dt>
471: <dt>"<code>text/ecmascript</code>"</dt>
472: <dt>"<code>text/javascript</code>"</dt>
473: <dt>"<code>text/javascript1.0</code>"</dt>
474: <dt>"<code>text/javascript1.1</code>"</dt>
475: <dt>"<code>text/javascript1.2</code>"</dt>
476: <dt>"<code>text/javascript1.3</code>"</dt>
477: <dt>"<code>text/javascript1.4</code>"</dt>
478: <dt>"<code>text/javascript1.5</code>"</dt>
479: <dt>"<code>text/jscript</code>"</dt>
480: <dt>"<code>text/livescript</code>"</dt>
481: <dt>"<code>text/x-ecmascript</code>"</dt>
482: <dt>"<code>text/x-javascript</code>"</dt>
483: <dd>JavaScript. <a href="references.html#refsECMA262">[ECMA262]</a></dd>
484:
485: <dt>"<code>text/javascript;e4x=1</code>"</dt>
486: <dd>JavaScript with ECMAScript for XML. <a href="references.html#refsECMA357">[ECMA357]</a></dd>
487:
488: </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
489: <code title="">script</code> production in the following ABNF, the
490: character set for which is Unicode. <a href="references.html#refsABNF">[ABNF]</a></p><pre>script = data1 *( escape [ script-start data3 ] "-->" data1 ) [ escape ]
491: escape = "<!--" data2 *( script-start data3 script-end data2 )
492:
493: data1 = <any string that doesn't contain a substring that matches not-data1>
494: not-data1 = <!-- script-end / -->"<!--" <!-- the script-end is redundant here since it would close the element -->
495:
496: data2 = <any string that doesn't contain a substring that matches not-data2>
497: not-data2 = <!-- script-end / -->script-start / "-->" <!-- the script-end is redundant here since it would close the element -->
498:
499: data3 = <any string that doesn't contain a substring that matches not-data3>
500: not-data3 = script-end / "-->"
501:
502: script-start = lt s c r i p t tag-end
503: script-end = lt slash s c r i p t tag-end
504:
505: lt = %x003C ; U+003C LESS-THAN SIGN character (<)
506: slash = %x002F ; U+002F SOLIDUS character (/)
507:
508: s = %x0053 ; U+0053 LATIN CAPITAL LETTER S
509: s =/ %x0073 ; U+0073 LATIN SMALL LETTER S
510: c = %x0043 ; U+0043 LATIN CAPITAL LETTER C
511: c =/ %x0063 ; U+0063 LATIN SMALL LETTER C
512: r = %x0052 ; U+0052 LATIN CAPITAL LETTER R
513: r =/ %x0072 ; U+0072 LATIN SMALL LETTER R
514: i = %x0049 ; U+0049 LATIN CAPITAL LETTER I
515: i =/ %x0069 ; U+0069 LATIN SMALL LETTER I
516: p = %x0050 ; U+0050 LATIN CAPITAL LETTER P
517: p =/ %x0070 ; U+0070 LATIN SMALL LETTER P
518: t = %x0054 ; U+0054 LATIN CAPITAL LETTER T
519: t =/ %x0074 ; U+0074 LATIN SMALL LETTER T
520:
521: tag-end = %x0009 ; U+0009 CHARACTER TABULATION
522: tag-end =/ %x000A ; U+000A LINE FEED (LF)
523: tag-end =/ %x000C ; U+000C FORM FEED (FF)
524: tag-end =/ %x0020 ; U+0020 SPACE
525: tag-end =/ %x002F ; U+002F SOLIDUS (/)
526: 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
527: documentation</a>, there are further restrictions on the contents
528: 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
529: contents of the <code><a href="#script">script</a></code> element, if any, must be such
530: that the value of the <code title="dom-script-text"><a href="#dom-script-text">text</a></code> IDL
531: attribute, which is derived from the element's contents, matches the
532: <code title="">documentation</code> production in the following
533: ABNF, the character set for which is Unicode. <a href="references.html#refsABNF">[ABNF]</a></p><pre>documentation = *( *( space / tab / comment ) [ line-comment ] newline )
534: comment = slash star *( not-star / star not-slash ) 1*star slash
535: line-comment = slash slash *not-newline
536:
537: ; characters
538: tab = %x0009 ; U+0009 TAB
539: newline = %x000A ; U+000A LINE FEED (LF)
540: space = %x0020 ; U+0020 SPACE
541: star = %x002A ; U+002A ASTERISK (*)
542: slash = %x002F ; U+002F SOLIDUS (/)
543: not-newline = %x0000-0009 / %x000B-10FFFF
544: ; a Unicode character other than U+000A LINE FEED (LF)
545: not-star = %x0000-0029 / %x002B-10FFFF
546: ; a Unicode character other than U+002A ASTERISK (*)
547: not-slash = %x0000-002E / %x0030-10FFFF
548: ; a Unicode character other than U+002F SOLIDUS (/)</pre><p class="note">This corresponds to putting the contents of the
549: element in JavaScript comments.</p><p class="note">This requirement is in addition to the earlier
550: restrictions on the syntax of contents of <code><a href="#script">script</a></code>
551: elements.</p><div class="example">
552:
553: <p>This allows authors to include documentation, such as license
554: information or API information, inside their documents while still
555: referring to external script files. The syntax is constrained so
556: that authors don't accidentally include what looks like valid
557: script while also providing a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute.</p>
558:
559: <pre><script src="cool-effects.js">
560: // create new instances using:
561: // var e = new Effect();
562: // start the effect using .play, stop using .stop:
563: // e.play();
564: // e.stop();
565: </script></pre>
566:
567: </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>
568: <dd><a href="content-models.html#metadata-content">Metadata content</a>.</dd>
569: <dd><a href="content-models.html#flow-content">Flow content</a>.</dd>
570: <dd><a href="content-models.html#phrasing-content">Phrasing content</a>.</dd>
571: <dt>Contexts in which this element may be used:</dt>
572: <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>
573: <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>
574: <dt>Content model:</dt>
575: <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>
576: <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>
577: <dd>Otherwise: text that conforms to the requirements given in the prose.</dd>
578: <dt>Content attributes:</dt>
579: <dd><a href="elements.html#global-attributes">Global attributes</a></dd>
580: <dt>DOM interface:</dt>
581: <dd>Uses <code><a href="elements.html#htmlelement">HTMLElement</a></code>.</dd>
582: </dl><p>The <code><a href="#the-noscript-element">noscript</a></code> element <a href="#represents">represents</a> nothing
583: if <a href="#concept-n-script" title="concept-n-script">scripting is enabled</a>, and
584: <a href="#represents">represents</a> its children if <a href="#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a>. It is used
585: to present different markup to user agents that support scripting
586: and those that don't support scripting, by affecting how the
587: document is parsed.</p><p>When used in <a href="dom.html#html-documents">HTML documents</a>, the allowed content
588: 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
589: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
590:
591: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only
592: <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>
593: elements.</p></dd>
594:
595: <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
596: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
597:
598: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only text,
599: except that invoking the <a href="#html-fragment-parsing-algorithm">HTML fragment parsing
1.12 mike 600: algorithm</a> <!-- (which disables <script type="text/javascript"> execution) --> with
1.11 mike 601: 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
602: 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
603: <code><a href="semantics.html#meta">meta</a></code> elements that would be conforming if they were
604: 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>
605:
606: <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
607: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
608:
609: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element's content model is
610: <a href="content-models.html#transparent">transparent</a>, with the additional restriction that a
611: <code><a href="#the-noscript-element">noscript</a></code> element must not have a <code><a href="#the-noscript-element">noscript</a></code>
612: element as an ancestor (that is, <code><a href="#the-noscript-element">noscript</a></code> can't be
613: nested).</p></dd>
614:
615: <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
616: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
617:
618: <dd>
619:
620: <p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only text,
621: except that the text must be such that running the following
622: algorithm results in a conforming document with no
623: <code><a href="#the-noscript-element">noscript</a></code> elements and no <code><a href="#script">script</a></code>
624: elements, and such that no step in the algorithm causes an
625: <a href="#html-parser">HTML parser</a> to flag a <a href="#parse-error">parse error</a>:</p>
626:
627: <ol><li>Remove every <code><a href="#script">script</a></code> element from the
628: document.</li>
629:
630: <li>Make a list of every <code><a href="#the-noscript-element">noscript</a></code> element in the
631: document. For every <code><a href="#the-noscript-element">noscript</a></code> element in that list,
632: perform the following steps:
633:
634: <ol><li>Let the <var title="">parent element</var> be the parent
635: element of the <code><a href="#the-noscript-element">noscript</a></code> element.</li>
636:
637: <li>Take all the children of the <var title="">parent element</var>
638: that come before the <code><a href="#the-noscript-element">noscript</a></code> element, and call these
639: elements <var title="">the before children</var>.</li>
640:
641: <li>Take all the children of the <var title="">parent element</var>
642: that come <em>after</em> the <code><a href="#the-noscript-element">noscript</a></code> element, and
643: call these elements <var title="">the after children</var>.</li>
644:
645: <li>Let <var title="">s</var> be the concatenation of all the
646: <a href="infrastructure.html#text-node">text node</a> children of the <code><a href="#the-noscript-element">noscript</a></code>
647: element.</li>
648:
649: <li>Set the <code title="dom-innerHTML"><a href="apis-in-html-documents.html#dom-innerhtml">innerHTML</a></code>
650: attribute of the <var title="">parent element</var> to the value
651: of <var title="">s</var>. (This, as a side-effect, causes the
652: <code><a href="#the-noscript-element">noscript</a></code> element to be removed from the
653: document.)</li>
654:
655: <li>Insert <var title="">the before children</var> at the start of
656: the <var title="">parent element</var>, preserving their original
657: relative order.</li>
658:
659: <li>Insert <var title="">the after children</var> at the end of the
660: <var title="">parent element</var>, preserving their original
661: relative order.</li>
662:
663: </ol></li>
664:
665: </ol></dd>
666:
667: </dl><p class="note">All these contortions are required because, for
668: historical reasons, the <code><a href="#the-noscript-element">noscript</a></code> element is handled
669: 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
670: 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
671: documents</a>.</p><p class="note"><strong>The <code><a href="#the-noscript-element">noscript</a></code> element is only
672: effective in <a href="syntax.html#syntax">the HTML syntax</a>, it has no effect in
673: <a href="the-xhtml-syntax.html#the-xhtml-syntax">the XHTML syntax</a>.</strong></p><div class="example">
674:
675: <p>In the following example, a <code><a href="#the-noscript-element">noscript</a></code> element is
676: used to provide fallback for a script.</p>
677:
678: <pre><form action="calcSquare.php">
679: <p>
680: <label for=x>Number</label>:
681: <input id="x" name="x" type="number">
682: </p>
683: <script>
684: var x = document.getElementById('x');
685: var output = document.createElement('p');
686: output.textContent = 'Type a number; it will be squared right then!';
687: x.form.appendChild(output);
688: x.form.onsubmit = function () { return false; }
689: x.oninput = function () {
690: var v = x.valueAsNumber;
691: output.textContent = v + ' squared is ' + v * v;
692: };
693: </script>
694: <noscript>
695: <input type=submit value="Calculate Square">
696: </noscript>
697: </form></pre>
698:
699: <p>When script is disabled, a button appears to do the calculation
700: on the server side. When script is enabled, the value is computed
701: on-the-fly instead.</p>
702:
703: <p>The <code><a href="#the-noscript-element">noscript</a></code> element is a blunt
704: instrument. Sometimes, scripts might be enabled, but for some
705: reason the page's script might fail. For this reason, it's
706: generally better to avoid using <code><a href="#the-noscript-element">noscript</a></code>, and to
707: instead design the script to change the page from being a
708: scriptless page to a scripted page on the fly, as in the next
709: example:</p>
710:
711: <pre><form action="calcSquare.php">
712: <p>
713: <label for=x>Number</label>:
714: <input id="x" name="x" type="number">
715: </p>
716: <strong><input id="submit" type=submit value="Calculate Square"></strong>
717: <script>
718: var x = document.getElementById('x');
719: var output = document.createElement('p');
720: output.textContent = 'Type a number; it will be squared right then!';
721: x.form.appendChild(output);
722: x.form.onsubmit = function () { return false; }
723: x.oninput = function () {
724: var v = x.valueAsNumber;
725: output.textContent = v + ' squared is ' + v * v;
726: };
727: <strong> var submit = document.getElementById('submit');
728: submit.parentNode.removeChild(submit);</strong>
729: </script>
730: </form></pre>
731:
732: <p>The above technique is also useful in XHTML, since
733: <code><a href="#the-noscript-element">noscript</a></code> is not supported in <a href="the-xhtml-syntax.html#the-xhtml-syntax">the XHTML
734: syntax</a>.</p>
735:
736: </div></body></html>
Webmaster