Annotation of html5/spec/scripting-1.html, revision 1.53
1.1 mike 1: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
2: <!DOCTYPE html>
1.48 mike 3: <html lang="en-US-x-Hixie" class="split chapter"><head><title>4.3 Scripting — HTML5 </title><style type="text/css">
1.1 mike 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, table tbody { 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: #DDFFDD; }
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:
1.29 mike 68: p > span:not([title=""]):not([class="XXX"]):not([class="impl"]):not([class="note"]),
69: li > span:not([title=""]):not([class="XXX"]):not([class="impl"]):not([class="note"]), { border-bottom: solid #9999CC; }
1.1 mike 70:
71: div.head { margin: 0 0 1em; padding: 1em 0 0 0; }
72: div.head p { margin: 0; }
73: div.head h1 { margin: 0; }
74: div.head .logo { float: right; margin: 0 1em; }
75: div.head .logo img { border: none } /* remove border from top image */
76: div.head dl { margin: 1em 0; }
77: div.head p.copyright, div.head p.alt { font-size: x-small; font-style: oblique; margin: 0; }
78:
79: body > .toc > li { margin-top: 1em; margin-bottom: 1em; }
80: body > .toc.brief > li { margin-top: 0.35em; margin-bottom: 0.35em; }
81: body > .toc > li > * { margin-bottom: 0.5em; }
82: body > .toc > li > * > li > * { margin-bottom: 0.25em; }
83: .toc, .toc li { list-style: none; }
84:
85: .brief { margin-top: 1em; margin-bottom: 1em; line-height: 1.1; }
86: .brief li { margin: 0; padding: 0; }
87: .brief li p { margin: 0; padding: 0; }
88:
89: .category-list { margin-top: -0.75em; margin-bottom: 1em; line-height: 1.5; }
90: .category-list::before { content: '\21D2\A0'; font-size: 1.2em; font-weight: 900; }
91: .category-list li { display: inline; }
92: .category-list li:not(:last-child)::after { content: ', '; }
93: .category-list li > span, .category-list li > a { text-transform: lowercase; }
94: .category-list li * { text-transform: none; } /* don't affect <code> nested in <a> */
95:
96: .XXX { color: #E50000; background: white; border: solid red; padding: 0.5em; margin: 1em 0; }
97: .XXX > :first-child { margin-top: 0; }
98: p .XXX { line-height: 3em; }
99: .annotation { border: solid thin black; background: #0C479D; color: white; position: relative; margin: 8px 0 20px 0; }
100: .annotation:before { position: absolute; left: 0; top: 0; width: 100%; height: 100%; margin: 6px -6px -6px 6px; background: #333333; z-index: -1; content: ''; }
101: .annotation :link, .annotation :visited { color: inherit; }
102: .annotation :link:hover, .annotation :visited:hover { background: transparent; }
103: .annotation span { border: none ! important; }
104: .note { color: green; background: transparent; font-family: sans-serif; }
105: .warning { color: red; background: transparent; }
106: .note, .warning { font-weight: bolder; font-style: italic; }
107: p.note, div.note { padding: 0.5em 2em; }
108: span.note { padding: 0 2em; }
109: .note p:first-child, .warning p:first-child { margin-top: 0; }
110: .note p:last-child, .warning p:last-child { margin-bottom: 0; }
111: .warning:before { font-style: normal; }
112: p.note:before { content: 'Note: '; }
113: p.warning:before { content: '\26A0 Warning! '; }
114:
115: .bookkeeping:before { display: block; content: 'Bookkeeping details'; font-weight: bolder; font-style: italic; }
116: .bookkeeping { font-size: 0.8em; margin: 2em 0; }
117: .bookkeeping p { margin: 0.5em 2em; display: list-item; list-style: square; }
1.9 mike 118: .bookkeeping dt { margin: 0.5em 2em 0; }
119: .bookkeeping dd { margin: 0 3em 0.5em; }
1.1 mike 120:
121: h4 { position: relative; z-index: 3; }
122: h4 + .element, h4 + div + .element { margin-top: -2.5em; padding-top: 2em; }
123: .element {
124: background: #EEEEFF;
125: color: black;
126: margin: 0 0 1em 0.15em;
127: padding: 0 1em 0.25em 0.75em;
128: border-left: solid #9999FF 0.25em;
129: position: relative;
130: z-index: 1;
131: }
132: .element:before {
133: position: absolute;
134: z-index: 2;
135: top: 0;
136: left: -1.15em;
137: height: 2em;
138: width: 0.9em;
139: background: #EEEEFF;
140: content: ' ';
141: border-style: none none solid solid;
142: border-color: #9999FF;
143: border-width: 0.25em;
144: }
145:
146: .example { display: block; color: #222222; background: #FCFCFC; border-left: double; margin-left: 2em; padding-left: 1em; }
147: td > .example:only-child { margin: 0 0 0 0.1em; }
148:
149: ul.domTree, ul.domTree ul { padding: 0 0 0 1em; margin: 0; }
150: ul.domTree li { padding: 0; margin: 0; list-style: none; position: relative; }
151: ul.domTree li li { list-style: none; }
152: 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; }
153: 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; }
154: ul.domTree span { font-style: italic; font-family: serif; }
155: ul.domTree .t1 code { color: purple; font-weight: bold; }
156: ul.domTree .t2 { font-style: normal; font-family: monospace; }
157: ul.domTree .t2 .name { color: black; font-weight: bold; }
158: ul.domTree .t2 .value { color: blue; font-weight: normal; }
159: ul.domTree .t3 code, .domTree .t4 code, .domTree .t5 code { color: gray; }
160: ul.domTree .t7 code, .domTree .t8 code { color: green; }
161: ul.domTree .t10 code { color: teal; }
162:
163: body.dfnEnabled dfn { cursor: pointer; }
164: .dfnPanel {
165: display: inline;
166: position: absolute;
167: z-index: 10;
168: height: auto;
169: width: auto;
170: padding: 0.5em 0.75em;
171: font: small sans-serif, Droid Sans Fallback;
172: background: #DDDDDD;
173: color: black;
174: border: outset 0.2em;
175: }
176: .dfnPanel * { margin: 0; padding: 0; font: inherit; text-indent: 0; }
177: .dfnPanel :link, .dfnPanel :visited { color: black; }
178: .dfnPanel p { font-weight: bolder; }
179: .dfnPanel * + p { margin-top: 0.25em; }
180: .dfnPanel li { list-style-position: inside; }
181:
182: #configUI { position: absolute; z-index: 20; top: 10em; right: 1em; width: 11em; font-size: small; }
183: #configUI p { margin: 0.5em 0; padding: 0.3em; background: #EEEEEE; color: black; border: inset thin; }
184: #configUI p label { display: block; }
185: #configUI #updateUI, #configUI .loginUI { text-align: center; }
186: #configUI input[type=button] { display: block; margin: auto; }
1.8 mike 187:
1.33 mike 188: fieldset { margin: 1em; padding: 0.5em 1em; }
189: fieldset > legend + * { margin-top: 0; }
1.28 mike 190: fieldset > :last-child { margin-bottom: 0; }
1.33 mike 191: fieldset p { margin: 0.5em 0; }
192:
1.47 mike 193: </style><link href="http://www.w3.org/StyleSheets/TR/W3C-ED" rel="stylesheet" type="text/css"><style type="text/css">
1.1 mike 194:
195: .applies thead th > * { display: block; }
196: .applies thead code { display: block; }
197: .applies tbody th { whitespace: nowrap; }
198: .applies td { text-align: center; }
199: .applies .yes { background: yellow; }
200:
1.10 mike 201: .matrix, .matrix td { border: hidden; text-align: right; }
1.1 mike 202: .matrix { margin-left: 2em; }
203:
204: .dice-example { border-collapse: collapse; border-style: hidden solid solid hidden; border-width: thin; margin-left: 3em; }
205: .dice-example caption { width: 30em; font-size: smaller; font-style: italic; padding: 0.75em 0; text-align: left; }
206: .dice-example td, .dice-example th { border: solid thin; width: 1.35em; height: 1.05em; text-align: center; padding: 0; }
207:
1.17 mike 208: td.eg { border-width: thin; text-align: center; }
209:
1.1 mike 210: #table-example-1 { border: solid thin; border-collapse: collapse; margin-left: 3em; }
211: #table-example-1 * { font-family: "Essays1743", serif; line-height: 1.01em; }
212: #table-example-1 caption { padding-bottom: 0.5em; }
213: #table-example-1 thead, #table-example-1 tbody { border: none; }
214: #table-example-1 th, #table-example-1 td { border: solid thin; }
215: #table-example-1 th { font-weight: normal; }
216: #table-example-1 td { border-style: none solid; vertical-align: top; }
217: #table-example-1 th { padding: 0.5em; vertical-align: middle; text-align: center; }
218: #table-example-1 tbody tr:first-child td { padding-top: 0.5em; }
219: #table-example-1 tbody tr:last-child td { padding-bottom: 1.5em; }
220: #table-example-1 tbody td:first-child { padding-left: 2.5em; padding-right: 0; width: 9em; }
221: #table-example-1 tbody td:first-child::after { content: leader(". "); }
222: #table-example-1 tbody td { padding-left: 2em; padding-right: 2em; }
223: #table-example-1 tbody td:first-child + td { width: 10em; }
224: #table-example-1 tbody td:first-child + td ~ td { width: 2.5em; }
225: #table-example-1 tbody td:first-child + td + td + td ~ td { width: 1.25em; }
226:
227: .apple-table-examples { border: none; border-collapse: separate; border-spacing: 1.5em 0em; width: 40em; margin-left: 3em; }
228: .apple-table-examples * { font-family: "Times", serif; }
229: .apple-table-examples td, .apple-table-examples th { border: none; white-space: nowrap; padding-top: 0; padding-bottom: 0; }
230: .apple-table-examples tbody th:first-child { border-left: none; width: 100%; }
231: .apple-table-examples thead th:first-child ~ th { font-size: smaller; font-weight: bolder; border-bottom: solid 2px; text-align: center; }
232: .apple-table-examples tbody th::after, .apple-table-examples tfoot th::after { content: leader(". ") }
233: .apple-table-examples tbody th, .apple-table-examples tfoot th { font: inherit; text-align: left; }
234: .apple-table-examples td { text-align: right; vertical-align: top; }
235: .apple-table-examples.e1 tbody tr:last-child td { border-bottom: solid 1px; }
236: .apple-table-examples.e1 tbody + tbody tr:last-child td { border-bottom: double 3px; }
237: .apple-table-examples.e2 th[scope=row] { padding-left: 1em; }
238: .apple-table-examples sup { line-height: 0; }
239:
240: .details-example img { vertical-align: top; }
241:
1.39 mike 242: #base64-table {
243: white-space: nowrap;
244: font-size: 0.6em;
245: column-width: 6em;
246: column-count: 5;
247: column-gap: 1em;
248: -moz-column-width: 6em;
249: -moz-column-count: 5;
250: -moz-column-gap: 1em;
251: -webkit-column-width: 6em;
252: -webkit-column-count: 5;
253: -webkit-column-gap: 1em;
254: }
255: #base64-table thead { display: none; }
256: #base64-table * { border: none; }
257: #base64-table tbody td:first-child:after { content: ':'; }
258: #base64-table tbody td:last-child { text-align: right; }
259:
1.1 mike 260: #named-character-references-table {
1.24 mike 261: white-space: nowrap;
1.1 mike 262: font-size: 0.6em;
1.24 mike 263: column-width: 30em;
1.1 mike 264: column-gap: 1em;
1.24 mike 265: -moz-column-width: 30em;
1.1 mike 266: -moz-column-gap: 1em;
1.24 mike 267: -webkit-column-width: 30em;
1.1 mike 268: -webkit-column-gap: 1em;
269: }
1.24 mike 270: #named-character-references-table > table > tbody > tr > td:first-child + td,
1.1 mike 271: #named-character-references-table > table > tbody > tr > td:last-child { text-align: center; }
272: #named-character-references-table > table > tbody > tr > td:last-child:hover > span { position: absolute; top: auto; left: auto; margin-left: 0.5em; line-height: 1.2; font-size: 5em; border: outset; padding: 0.25em 0.5em; background: white; width: 1.25em; height: auto; text-align: center; }
1.24 mike 273: #named-character-references-table > table > tbody > tr#entity-CounterClockwiseContourIntegral > td:first-child { font-size: 0.5em; }
1.1 mike 274:
1.2 mike 275: .glyph.control { color: red; }
276:
1.4 mike 277: @font-face {
278: font-family: 'Essays1743';
279: src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743.ttf');
280: }
281: @font-face {
282: font-family: 'Essays1743';
283: font-weight: bold;
284: src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743-Bold.ttf');
285: }
286: @font-face {
287: font-family: 'Essays1743';
288: font-style: italic;
289: src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743-Italic.ttf');
290: }
291: @font-face {
292: font-family: 'Essays1743';
293: font-style: italic;
294: font-weight: bold;
295: src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743-BoldItalic.ttf');
296: }
297:
1.1 mike 298: </style><style type="text/css">
299: .domintro:before { display: table; margin: -1em -0.5em -0.5em auto; width: auto; content: 'This box is non-normative. Implementation requirements are given below this box.'; color: black; font-style: italic; border: solid 2px; background: white; padding: 0 0.25em; }
1.47 mike 300: </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%0Ahtml%20%7B%20border:%20solid%20yellow;%20%7D%20.domintro:before%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%20.domintro:before%20%7B%20background:%20%23FFEEEE;%20%7D" id="highlight" rel="alternate stylesheet" title="Highlight implementation requirements"><script type="text/javascript">
301: function getCookie(name) {
302: var params = location.search.substr(1).split("&");
303: for (var index = 0; index < params.length; index++) {
304: if (params[index] == name)
305: return "1";
306: var data = params[index].split("=");
307: if (data[0] == name)
308: return unescape(data[1]);
309: }
310: var cookies = document.cookie.split("; ");
311: for (var index = 0; index < cookies.length; index++) {
312: var data = cookies[index].split("=");
313: if (data[0] == name)
314: return unescape(data[1]);
315: }
316: return null;
317: }
318: function load(script) {
319: var e = document.createElement('script');
320: e.setAttribute('src', 'http://www.whatwg.org/specs/web-apps/current-work/' + script + '?' + encodeURIComponent(location) + '&' + encodeURIComponent(document.referrer));
321: document.body.appendChild(e);
322: }
323: function init() {
324: if (location.search == '?slow-browser')
325: return;
326: var configUI = document.createElement('div');
327: configUI.id = 'configUI';
328: document.body.appendChild(configUI);
329: // load('reviewer.js'); // would need cross-site XHR
330: if (document.getElementById('head'))
331: load('toc.js');
332: load('styler.js');
333: // load('updater.js'); // would need cross-site XHR
334: load('dfn.js'); // doesn't support split-out specs, but, oh well.
335: // load('status.js'); // would need cross-site XHR
336: if (getCookie('profile') == '1')
337: document.getElementsByTagName('h2')[0].textContent += '; load: ' + (new Date() - loadTimer) + 'ms';
338: fixBrokenLink();
339: }
340: </script>
1.1 mike 341: <script src="link-fixup.js"></script>
1.35 mike 342: <link href="style.css" rel="stylesheet"><link href="semantics.html" title="4 The elements of HTML" rel="prev">
1.1 mike 343: <link href="spec.html#contents" title="Table of contents" rel="index">
344: <link href="sections.html" title="4.4 Sections" rel="next">
1.47 mike 345: </head><body onload="fixBrokenLink(); init()"><div class="head" id="head">
1.1 mike 346: <p><a href="http://www.w3.org/"><img alt="W3C" height="48" src="http://www.w3.org/Icons/w3c_home" width="72"></a></p>
1.3 mike 347:
1.1 mike 348: <h1>HTML5</h1>
349: </div><div>
1.35 mike 350: <a href="semantics.html" class="prev">4 The elements of HTML</a> –
1.1 mike 351: <a href="spec.html#contents">Table of contents</a> –
1.35 mike 352: <a href="sections.html" class="next">4.4 Sections</a>
1.1 mike 353: <ol class="toc"><li><ol><li><a href="scripting-1.html#scripting-1"><span class="secno">4.3 </span>Scripting</a>
1.50 mike 354: <ol><li><a href="scripting-1.html#the-script-element"><span class="secno">4.3.1 </span>The <code>script</code> element</a>
1.49 mike 355: <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><li><a href="scripting-1.html#scriptTagXSLT"><span class="secno">4.3.1.4 </span>Interaction of <code>script</code> elements and XSLT</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>
1.1 mike 356:
1.15 mike 357: <h3 id="scripting-1"><span class="secno">4.3 </span>Scripting</h3><p>Scripts allow authors to add interactivity to their documents.</p><p>Authors are encouraged to use declarative alternatives to
1.1 mike 358: scripting where possible, as declarative mechanisms are often more
359: maintainable, and many users disable scripting.</p><div class="example">
360: <p>For example, instead of using script to show or hide a section
361: to show more details, the <code><a href="interactive-elements.html#the-details-element">details</a></code> element could be
362: used.</p>
363: </div><p>Authors are also encouraged to make their applications degrade
364: gracefully in the absence of scripting support.</p><div class="example">
365: <p>For example, if an author provides a link in a table header to
366: dynamically resort the table, the link could also be made to
367: function without scripts by requesting the sorted table from the
368: server.</p>
1.50 mike 369: </div><h4 id="the-script-element"><span class="secno">4.3.1 </span>The <dfn id="script"><code>script</code></dfn> element</h4><dl class="element"><dt>Categories</dt>
1.1 mike 370: <dd><a href="content-models.html#metadata-content">Metadata content</a>.</dd>
371: <dd><a href="content-models.html#flow-content">Flow content</a>.</dd>
372: <dd><a href="content-models.html#phrasing-content">Phrasing content</a>.</dd>
1.16 mike 373: <dt>Contexts in which this element can be used:</dt>
1.1 mike 374: <dd>Where <a href="content-models.html#metadata-content">metadata content</a> is expected.</dd>
375: <dd>Where <a href="content-models.html#phrasing-content">phrasing content</a> is expected.</dd>
376: <dt>Content model:</dt>
377: <dd>If there is no <code title="attr-script-src"><a href="#attr-script-src">src</a></code>
378: attribute, depends on the value of the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, but must match
379: <a href="#restrictions-for-contents-of-script-elements">script content restrictions</a>.</dd>
380: <dd>If there <em>is</em> a <code title="attr-script-src"><a href="#attr-script-src">src</a></code>
381: attribute, the element must be either empty or contain only
382: <a href="#inline-documentation-for-external-scripts">script documentation</a> that also matches <a href="#restrictions-for-contents-of-script-elements">script
383: content restrictions</a>.</dd>
384: <dt>Content attributes:</dt>
385: <dd><a href="elements.html#global-attributes">Global attributes</a></dd>
386: <dd><code title="attr-script-src"><a href="#attr-script-src">src</a></code></dd>
387: <dd><code title="attr-script-async"><a href="#attr-script-async">async</a></code></dd>
388: <dd><code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code></dd>
389: <dd><code title="attr-script-type"><a href="#attr-script-type">type</a></code></dd>
390: <dd><code title="attr-script-charset"><a href="#attr-script-charset">charset</a></code></dd>
391: <dt>DOM interface:</dt>
392: <dd>
393: <pre class="idl">interface <dfn id="htmlscriptelement">HTMLScriptElement</dfn> : <a href="elements.html#htmlelement">HTMLElement</a> {
394: attribute DOMString <a href="#dom-script-src" title="dom-script-src">src</a>;
395: attribute boolean <a href="#dom-script-async" title="dom-script-async">async</a>;
396: attribute boolean <a href="#dom-script-defer" title="dom-script-defer">defer</a>;
397: attribute DOMString <a href="#dom-script-type" title="dom-script-type">type</a>;
398: attribute DOMString <a href="#dom-script-charset" title="dom-script-charset">charset</a>;
399: attribute DOMString <a href="#dom-script-text" title="dom-script-text">text</a>;
400: };</pre>
401: </dd>
1.50 mike 402: </dl><p>The <code><a href="#the-script-element">script</a></code> element allows authors to include dynamic
1.1 mike 403: script and data blocks in their documents. The element does not
404: <a href="rendering.html#represents" title="represents">represent</a> content for the user.</p><p>When used to include dynamic scripts, the scripts may either be
405: embedded inline or may be imported from an external file using the
406: <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute. If the language
407: is not that described by "<code title="">text/javascript</code>",
408: then the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute must
1.41 mike 409: be present, as described below. Whatever language is used, the
1.50 mike 410: contents of the <code><a href="#the-script-element">script</a></code> element must conform with the
1.41 mike 411: requirements of that language's specification.</p><p>When used to include data blocks (as opposed to scripts), the
1.1 mike 412: data must be embedded inline, the format of the data must be given
1.41 mike 413: using the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, the
414: <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute must not be
1.50 mike 415: specified, and the contents of the <code><a href="#the-script-element">script</a></code> element must
1.41 mike 416: conform to the requirements defined for the format used.</p><p>The <dfn id="attr-script-type" title="attr-script-type"><code>type</code></dfn>
1.1 mike 417: attribute gives the language of the script or format of the data. If
418: the attribute is present, its value must be a <a href="infrastructure.html#valid-mime-type">valid MIME
419: type</a>. The <code title="">charset</code> parameter must not be
420: specified. The default, which is used if the attribute is absent,
421: is "<code title="">text/javascript</code>".</p><p>The <dfn id="attr-script-src" title="attr-script-src"><code>src</code></dfn>
422: attribute, if specified, gives the address of the external script
423: resource to use. The value of the attribute must be a <a href="urls.html#valid-non-empty-url-potentially-surrounded-by-spaces">valid
424: non-empty URL potentially surrounded by spaces</a> identifying a
425: script resource of the type given by the <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, if the attribute is
426: present, or of the type "<code title="">text/javascript</code>", if
427: the attribute is absent. A resource is a script resource of a given
428: type if that type identifies a scripting language and the resource
429: conforms with the requirements of that language's specification.</p><p>The <dfn id="attr-script-charset" title="attr-script-charset"><code>charset</code></dfn>
430: attribute gives the character encoding of the external script
431: 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
432: attribute is set, its value must be a valid character encoding name,
433: must be an <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a> match for the
434: <a href="infrastructure.html#preferred-mime-name">preferred MIME name</a> for that encoding, and must match
435: the encoding given in the <code title="">charset</code> parameter of
436: the <a href="fetching-resources.html#content-type" title="Content-Type">Content-Type metadata</a> of the
437: 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
438: <dfn id="attr-script-defer" title="attr-script-defer"><code>defer</code></dfn> attributes
439: are <a href="common-microsyntaxes.html#boolean-attribute" title="boolean attribute">boolean attributes</a> that
440: indicate how the script should be executed. 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 must not be
441: specified if the <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute
442: is not present.</p><p>There are three possible modes that can be selected using these
443: attributes. If the <code title="attr-script-async"><a href="#attr-script-async">async</a></code>
444: attribute is present, then the script will be executed
445: 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
446: the <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> attribute is
447: present, then the script is executed when the page has finished
448: parsing. If neither attribute is present, then the script is
449: fetched and executed immediately, before the user agent continues
450: parsing the page.</p><p class="note">The exact processing details for these attributes
451: are, for mostly historical reasons, somewhat non-trivial, involving
452: a number of aspects of HTML. The implementation requirements are
453: therefore by necessity scattered throughout the specification. The
454: algorithms below (in this section) describe the core of this
455: processing, but these algorithms reference and are referenced by the
1.50 mike 456: parsing rules for <code><a href="#the-script-element">script</a></code> <a href="tree-construction.html#scriptTag">start</a>
1.48 mike 457: and <a href="tree-construction.html#scriptEndTag">end</a> tags in HTML, <a href="tree-construction.html#scriptForeignEndTag">in foreign content</a>, and <a href="the-xhtml-syntax.html#scriptTagXML">in XML</a>, the rules for the <code title="dom-document-write"><a href="apis-in-html-documents.html#dom-document-write">document.write()</a></code> method, the
1.1 mike 458: handling of <a href="webappapis.html#scripting">scripting</a>, etc.</p><p>The <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> attribute may be
459: specified even if the <code title="attr-script-async"><a href="#attr-script-async">async</a></code>
460: attribute is specified, to cause legacy Web browsers that only
461: 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
462: synchronous blocking behavior that is the default.</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
463: direct effect; these attribute are only used at specific times
1.48 mike 464: described below.</p><div class="impl">
1.1 mike 465:
1.50 mike 466: <p>A <code><a href="#the-script-element">script</a></code> element has several associated pieces of
1.1 mike 467: state.</p>
468:
469: <p>The first is a flag indicating whether or not the script block
470: has been <dfn id="already-started">"already started"</dfn>. Initially,
1.50 mike 471: <code><a href="#the-script-element">script</a></code> elements must have this flag unset (script
1.1 mike 472: blocks, when created, are not "already started"). When a
1.50 mike 473: <code><a href="#the-script-element">script</a></code> element is <a href="infrastructure.html#concept-clone" title="concept-clone">cloned</a>, the "already started" flag, if
1.40 mike 474: set, must be propagated to the clone when it is created.</p>
1.1 mike 475:
476: <p>The second is a flag indicating whether the element was
1.50 mike 477: <dfn id="parser-inserted">"parser-inserted"</dfn>. Initially, <code><a href="#the-script-element">script</a></code>
1.1 mike 478: elements must have this flag unset. It is set by the <a href="parsing.html#html-parser">HTML
1.50 mike 479: parser</a> and the <a href="the-xhtml-syntax.html#xml-parser">XML parser</a> on <code><a href="#the-script-element">script</a></code>
1.1 mike 480: elements they insert and affects the processing of those
481: elements.</p>
482:
1.39 mike 483: <p>The third is a flag indicating whether the element will
1.50 mike 484: <dfn id="force-async">"force-async"</dfn>. Initially, <code><a href="#the-script-element">script</a></code> elements
1.39 mike 485: must have this flag set. It is unset by the <a href="parsing.html#html-parser">HTML parser</a>
1.50 mike 486: and the <a href="the-xhtml-syntax.html#xml-parser">XML parser</a> on <code><a href="#the-script-element">script</a></code> elements they
487: insert. In addition, whenever a <code><a href="#the-script-element">script</a></code> element whose
1.39 mike 488: <a href="#force-async">"force-async"</a> flag is set has a <code title="attr-script-async"><a href="#attr-script-async">async</a></code> content attribute added, the
1.48 mike 489: element's <a href="#force-async">"force-async"</a> flag must be unset.</p>
1.39 mike 490: <p>The fourth is a flag indicating whether or not the script block is
1.1 mike 491: <dfn id="ready-to-be-parser-executed">"ready to be parser-executed"</dfn>. Initially,
1.50 mike 492: <code><a href="#the-script-element">script</a></code> elements must have this flag unset (script
1.1 mike 493: blocks, when created, are not "ready to be parser-executed"). This
494: flag is used only for elements that are also
495: <a href="#parser-inserted">"parser-inserted"</a>, to let the parser know when to
496: execute the script.</p>
497:
1.23 mike 498: <p>The last few pieces of state are <dfn id="the-script-block-s-type"><var>the script block's
499: type</var></dfn>, <dfn id="the-script-block-s-character-encoding"><var>the script block's character
500: encoding</var></dfn>, and <dfn id="the-script-block-s-fallback-character-encoding"><var>the script block's fallback
501: character encoding</var></dfn>. They are determined when the script
1.40 mike 502: is prepared, based on the attributes on the element at that time,
1.50 mike 503: and the <code><a href="infrastructure.html#document">Document</a></code> of the <code><a href="#the-script-element">script</a></code>
1.40 mike 504: element.</p>
1.1 mike 505:
1.50 mike 506: <p>When a <code><a href="#the-script-element">script</a></code> element that is not marked as being
1.1 mike 507: <a href="#parser-inserted">"parser-inserted"</a> experiences one of the events listed
1.50 mike 508: in the following list, the user agent must synchronously <a href="#prepare-a-script" title="prepare a script">prepare</a> the <code><a href="#the-script-element">script</a></code>
1.1 mike 509: element:</p>
510:
1.50 mike 511: <ul><li>The <code><a href="#the-script-element">script</a></code> element gets <a href="infrastructure.html#insert-an-element-into-a-document" title="insert an
1.1 mike 512: element into a document">inserted into a document</a>.</li>
513:
1.50 mike 514: <li>The <code><a href="#the-script-element">script</a></code> element is <a href="infrastructure.html#in-a-document">in a
1.1 mike 515: <code>Document</code></a> and its child nodes are changed.</li>
516:
1.50 mike 517: <li>The <code><a href="#the-script-element">script</a></code> element is <a href="infrastructure.html#in-a-document">in a
1.1 mike 518: <code>Document</code></a> and has a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute set where previously
519: the element had no such attribute.</li>
520:
1.40 mike 521: </ul><p>To <dfn id="prepare-a-script" title="prepare a script">prepare a script</dfn>, the user
522: agent must act as follows:</p>
1.1 mike 523:
1.19 mike 524: <ol><li>
1.16 mike 525:
1.50 mike 526: <p>If the <code><a href="#the-script-element">script</a></code> element is marked as having
1.19 mike 527: <a href="#already-started">"already started"</a>, then the user agent must abort
528: these steps at this point. The script is not executed.</p>
1.16 mike 529:
530: </li>
531:
1.18 mike 532: <li>
533:
534: <p>If the element has its <a href="#parser-inserted">"parser-inserted"</a> flag set,
535: then set <var title="">was-parser-inserted</var> to true and unset
536: the element's <a href="#parser-inserted">"parser-inserted"</a> flag. Otherwise, set
537: <var title="">was-parser-inserted</var> to false.</p>
538:
539: <p class="note">This is done so that if parser-inserted
1.50 mike 540: <code><a href="#the-script-element">script</a></code> elements fail to run when the parser tries to
1.18 mike 541: run them, e.g. because they are empty or specify an unsupported
542: scripting language, another script can later mutate them and cause
543: them to run again.</p>
544:
1.48 mike 545:
1.18 mike 546:
547: </li>
548:
1.39 mike 549: <li>
550:
551: <p>If <var title="">was-parser-inserted</var> is true and the
552: element does not have an <code title="attr-script-async"><a href="#attr-script-async">async</a></code> attribute, then set the
553: element's <a href="#force-async">"force-async"</a> flag to true.</p>
554:
555: <p class="note">This is done so that if a parser-inserted
1.50 mike 556: <code><a href="#the-script-element">script</a></code> element fails to run when the parser tries to
1.39 mike 557: run it, but it is later executed after a script dynamically
558: updates it, it will execute asynchronously even if the
559: <code title="attr-script-async"><a href="#attr-script-async">async</a></code> attribute isn't
560: set.</p>
561:
562: </li>
563:
1.16 mike 564: <li id="script-processing-empty">
565:
566: <p>If the element has no <code title="attr-script-src"><a href="#attr-script-src">src</a></code>
1.18 mike 567: attribute, and its child nodes, if any, consist only of comment
568: nodes and empty <a href="infrastructure.html#text-node" title="text node">text nodes</a>, then
569: the user agent must abort these steps at this point. The script is
570: not executed.</p>
1.16 mike 571:
572: </li>
573:
1.25 mike 574: <li>
575:
576: <p>If the element is not <a href="infrastructure.html#in-a-document">in a <code>Document</code></a>,
577: then the user agent must abort these steps at this point. The
578: script is not executed.</p>
579:
580: </li>
581:
1.16 mike 582: <li id="script-processing-prepare">
1.1 mike 583:
584: <p>If either:</p>
585:
1.50 mike 586: <ul class="brief"><li>the <code><a href="#the-script-element">script</a></code> element has a <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute and its value is
1.1 mike 587: the empty string, or</li>
588:
1.50 mike 589: <li>the <code><a href="#the-script-element">script</a></code> element has no <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute but it has a <code title="attr-script-language"><a href="obsolete.html#attr-script-language">language</a></code> attribute and
1.1 mike 590: <em>that</em> attribute's value is the empty string, or</li>
591:
1.50 mike 592: <li>the <code><a href="#the-script-element">script</a></code> element has neither a <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute nor a <code title="attr-script-language"><a href="obsolete.html#attr-script-language">language</a></code> attribute, then</li>
1.1 mike 593:
594: </ul><p>...let <var><a href="#the-script-block-s-type">the script block's type</a></var> for this
1.50 mike 595: <code><a href="#the-script-element">script</a></code> element be "<code title="">text/javascript</code>".</p>
1.1 mike 596:
1.50 mike 597: <p>Otherwise, if the <code><a href="#the-script-element">script</a></code> element has a <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute, let <var><a href="#the-script-block-s-type">the
598: script block's type</a></var> for this <code><a href="#the-script-element">script</a></code> element be
1.1 mike 599: the value of that attribute with any leading or trailing sequences
600: of <a href="common-microsyntaxes.html#space-character" title="space character">space characters</a>
601: removed.</p>
602:
603: <p>Otherwise, the element has a non-empty <code title="attr-script-language"><a href="obsolete.html#attr-script-language">language</a></code> attribute; let
1.50 mike 604: <var><a href="#the-script-block-s-type">the script block's type</a></var> for this <code><a href="#the-script-element">script</a></code>
1.48 mike 605: element be the concatenation of the string "<code title="">text/</code>" followed by the value of the <code title="attr-script-language"><a href="obsolete.html#attr-script-language">language</a></code> attribute.</p>
1.1 mike 606: <p class="note">The <code title="attr-script-language"><a href="obsolete.html#attr-script-language">language</a></code> attribute is never
607: conforming, and is always ignored if there is a <code title="attr-script-type"><a href="#attr-script-type">type</a></code> attribute present.</p>
608:
609: </li>
610:
1.16 mike 611: <li>
612:
613: <p>If the user agent does not <a href="#support-the-scripting-language">support the scripting
614: language</a> given by <var><a href="#the-script-block-s-type">the script block's type</a></var> for
1.50 mike 615: this <code><a href="#the-script-element">script</a></code> element, then the user agent must abort
1.16 mike 616: these steps at this point. The script is not executed.</p>
617:
618: </li>
619:
1.39 mike 620: <li>
1.18 mike 621:
1.39 mike 622: <p>If <var title="">was-parser-inserted</var> is true, then flag
623: the element as <a href="#parser-inserted">"parser-inserted"</a> again, and set the
624: element's <a href="#force-async">"force-async"</a> flag to false.</p>
1.18 mike 625:
626: </li>
627:
1.39 mike 628: <li id="script-processing-start">
1.18 mike 629:
1.39 mike 630: <p>The user agent must set the element's <a href="#already-started">"already
631: started"</a> flag.</p>
1.18 mike 632:
1.40 mike 633: <p class="note">The state of the element at this moment <a href="#establish-script-block-source">is later used</a> to
634: determine the script source.</p>
635:
636: </li>
637:
638: <li>
639:
640: <p>If the element is flagged as <a href="#parser-inserted">"parser-inserted"</a>,
641: but the element's <code><a href="infrastructure.html#document">Document</a></code> is not the
642: <code><a href="infrastructure.html#document">Document</a></code> of the parser that created the element, then
643: abort these steps.</p>
644:
1.18 mike 645: </li>
646:
1.19 mike 647: <li id="script-processing-noscript">
648:
649: <p>If <a href="webappapis.html#concept-n-noscript" title="concept-n-noscript">scripting is
1.50 mike 650: disabled</a> for the <code><a href="#the-script-element">script</a></code> element, then the user
1.19 mike 651: agent must abort these steps at this point. The script is not
652: executed.</p>
653:
1.40 mike 654: <p class="note">The definition of <a href="webappapis.html#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a> means
655: that, amongst others, the following scripts will not execute:
656: scripts in <code>XMLHttpRequest</code>'s <code title="dom-XMLHttpRequest-responseXML">responseXML</code>
1.49 mike 657: documents, scripts in <code>DOMParser</code>-created documents,
658: scripts in documents created by <code>XSLTProcessor</code>'s <code title="dom-XSLTProcessor-transformToDocument">transformToDocument</code>
659: feature, and scripts that are first inserted by a script into a
1.40 mike 660: <code><a href="infrastructure.html#document">Document</a></code> that was created using the <code title="dom-DOMImplementation-createDocument"><a href="infrastructure.html#dom-domimplementation-createdocument">createDocument()</a></code>
1.48 mike 661: API. <a href="references.html#refsXHR">[XHR]</a> <a href="references.html#refsDOMPARSER">[DOMPARSER]</a> <a href="references.html#refsDOMCORE">[DOMCORE]</a></p>
1.40 mike 662:
663:
1.19 mike 664: </li>
665:
1.1 mike 666: <li id="script-processing-for">
667:
1.50 mike 668: <p>If the <code><a href="#the-script-element">script</a></code> element has an <code title="attr-script-event"><a href="obsolete.html#attr-script-event">event</a></code> attribute and a <code title="attr-script-for"><a href="obsolete.html#attr-script-for">for</a></code> attribute, then run these
1.1 mike 669: substeps:</p>
670:
671: <ol><li><p>Let <var title="">for</var> be the value of the <code title="attr-script-for"><a href="obsolete.html#attr-script-for">for</a></code> attribute.</p></li>
672:
673: <li><p>Let <var title="">event</var> be the value of the <code title="attr-script-event"><a href="obsolete.html#attr-script-event">event</a></code> attribute.</p></li>
674:
675: <li><p><a href="common-microsyntaxes.html#strip-leading-and-trailing-whitespace">Strip leading and trailing whitespace</a> from
676: <var title="">event</var> and <var title="">for</var>.</p></li>
677:
678: <li><p>If <var title="">for</var> is not an <a href="infrastructure.html#ascii-case-insensitive">ASCII
679: case-insensitive</a> match for the string "<code title="">window</code>", then the user agent must abort these
680: steps at this point. The script is not executed.</p></li>
681:
682: <li><p>If <var title="">event</var> is not an <a href="infrastructure.html#ascii-case-insensitive">ASCII
683: case-insensitive</a> match for either the string "<code title="">onload</code>" or the string "<code title="">onload()</code>", then the user agent must abort these
684: steps at this point. The script is not executed.</p></li>
685:
686: </ol></li>
687:
1.19 mike 688: <li id="script-processing-encoding">
689:
1.50 mike 690: <p>If the <code><a href="#the-script-element">script</a></code> element has a <code title="attr-script-charset"><a href="#attr-script-charset">charset</a></code> attribute, then let
1.19 mike 691: <var><a href="#the-script-block-s-character-encoding">the script block's character encoding</a></var> for this
1.50 mike 692: <code><a href="#the-script-element">script</a></code> element be the encoding given by the <code title="attr-script-charset"><a href="#attr-script-charset">charset</a></code> attribute.</p>
1.19 mike 693:
1.23 mike 694: <p>Otherwise, let <var><a href="#the-script-block-s-fallback-character-encoding">the script block's fallback character
1.50 mike 695: encoding</a></var> for this <code><a href="#the-script-element">script</a></code> element be the same as
1.23 mike 696: <a href="dom.html#document-s-character-encoding" title="document's character encoding">the encoding of the
697: document itself</a>.</p>
698:
699: <p class="note">Only one of these two pieces of state is set.</p>
1.19 mike 700:
701: </li>
702:
1.1 mike 703: <li id="script-processing-src-prepare">
704:
705: <p>If the element has a <code title="attr-script-src"><a href="#attr-script-src">src</a></code>
706: attribute whose value is not the empty string, then the value of
707: that attribute must be <a href="urls.html#resolve-a-url" title="resolve a url">resolved</a>
708: relative to the element, and if that is successful, the specified
709: resource must then be <a href="fetching-resources.html#fetch" title="fetch">fetched</a>, from the
710: <a href="origin-0.html#origin">origin</a> of the element's <code><a href="infrastructure.html#document">Document</a></code>.</p>
1.48 mike 711:
1.1 mike 712:
713: <p>If the <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute's
714: value is the empty string or if it could not be resolved, then the
715: user agent must <a href="webappapis.html#queue-a-task">queue a task</a> to <a href="webappapis.html#fire-a-simple-event">fire a simple
716: event</a> named <code title="event-error">error</code> at the
717: element, and abort these steps.</p>
718:
719: <p>For historical reasons, if the <a href="urls.html#url">URL</a> is a <a href="webappapis.html#javascript-protocol" title="javascript protocol"><code title="">javascript:</code>
720: URL</a>, then the user agent must not, despite the requirements
721: in the definition of the <a href="fetching-resources.html#fetch" title="fetch">fetching</a>
722: algorithm, actually execute the script in the URL; instead the
723: user agent must act as if it had received an empty HTTP 400
724: response.</p>
725:
726: <p>For performance reasons, user agents may start fetching the
727: script as soon as the attribute is set, instead, in the hope that
728: the element will be inserted into the document. Either way, once
729: the element is <a href="infrastructure.html#insert-an-element-into-a-document" title="insert an element into a
730: document">inserted into the document</a>, the load must have
731: started. If the UA performs such prefetching, but the element is
732: never inserted in the document, or the <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute is dynamically
1.48 mike 733: changed, then the
1.1 mike 734: user agent will not execute the script, and the fetching process
735: will have been effectively wasted.</p>
736:
737: </li>
738:
1.48 mike 739:
1.1 mike 740: <li>
741:
742: <p>Then, the first of the following options that describes the
743: situation must be followed:</p>
744:
745: <dl class="switch"><dt id="script-processing-defer">If the element has a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute, and the element has
746: a <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code> attribute, and the
747: element has been flagged as <a href="#parser-inserted">"parser-inserted"</a>, and
748: the element does not have an <code title="attr-script-async"><a href="#attr-script-async">async</a></code> attribute</dt>
749:
750: <dd>
751:
752: <p>The element must be added to the end of the <dfn id="list-of-scripts-that-will-execute-when-the-document-has-finished-parsing">list of
753: scripts that will execute when the document has finished
1.20 mike 754: parsing</dfn> associated with the <code><a href="infrastructure.html#document">Document</a></code> of the
755: parser that created the element.</p>
1.1 mike 756:
757: <p>The <a href="webappapis.html#concept-task" title="concept-task">task</a> that the
758: <a href="webappapis.html#networking-task-source">networking task source</a> places on the <a href="webappapis.html#task-queue">task
759: queue</a> once the <a href="fetching-resources.html#fetch" title="fetch">fetching
760: algorithm</a> has completed must set the element's
761: <a href="#ready-to-be-parser-executed">"ready to be parser-executed"</a> flag. The parser will
762: handle executing the script.</p>
763:
764: </dd>
765:
766:
767: <dt id="script-processing-parser-inserted">If the element has a
768: <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute, and the
769: element has been flagged as <a href="#parser-inserted">"parser-inserted"</a>, and
770: the element does not have an <code title="attr-script-async"><a href="#attr-script-async">async</a></code> attribute</dt>
771:
772: <dd>
773:
774: <p>The element is the <a href="#pending-parsing-blocking-script">pending parsing-blocking
1.20 mike 775: script</a> of the <code><a href="infrastructure.html#document">Document</a></code> of the parser that
776: created the element. (There can only be one such script per
777: <code><a href="infrastructure.html#document">Document</a></code> at a time.)</p>
1.1 mike 778:
779: <p>The <a href="webappapis.html#concept-task" title="concept-task">task</a> that the
780: <a href="webappapis.html#networking-task-source">networking task source</a> places on the <a href="webappapis.html#task-queue">task
781: queue</a> once the <a href="fetching-resources.html#fetch" title="fetch">fetching
782: algorithm</a> has completed must set the element's
783: <a href="#ready-to-be-parser-executed">"ready to be parser-executed"</a> flag. The parser will
784: handle executing the script.</p>
785:
786: </dd>
787:
788:
789: <dt id="script-processing-style-delayed">If the element does not
1.33 mike 790: have a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute, and
791: the element has been flagged as <a href="#parser-inserted">"parser-inserted"</a>,
792: and the <code><a href="infrastructure.html#document">Document</a></code> of the <a href="parsing.html#html-parser">HTML parser</a> or
1.50 mike 793: <a href="the-xhtml-syntax.html#xml-parser">XML parser</a> that created the <code><a href="#the-script-element">script</a></code>
1.33 mike 794: element <a href="semantics.html#has-a-style-sheet-that-is-blocking-scripts">has a style sheet that is blocking
795: scripts</a></dt>
1.1 mike 796:
797: <dd>
798:
799: <p>The element is the <a href="#pending-parsing-blocking-script">pending parsing-blocking
1.20 mike 800: script</a> of the <code><a href="infrastructure.html#document">Document</a></code> of the parser that
801: created the element. (There can only be one such script per
802: <code><a href="infrastructure.html#document">Document</a></code> at a time.)</p>
1.1 mike 803:
804: <p>Set the element's <a href="#ready-to-be-parser-executed">"ready to be parser-executed"</a>
805: flag. The parser will handle executing the script.</p>
806:
807: </dd>
808:
809:
1.39 mike 810: <dt id="script-processing-src-sync">If the element has a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute, does not have an
811: <code title="attr-script-async"><a href="#attr-script-async">async</a></code> attribute, and does
812: not have the <a href="#force-async">"force-async"</a> flag set</dt>
813:
814: <dd>
815:
816: <p>The element must be added to the end of the <dfn id="list-of-scripts-that-will-execute-in-order-as-soon-as-possible">list of
817: scripts that will execute in order as soon as possible</dfn>
818: associated with the <code><a href="infrastructure.html#document">Document</a></code> of the
1.50 mike 819: <code><a href="#the-script-element">script</a></code> element at the time the <a href="#prepare-a-script">prepare a
1.39 mike 820: script</a> algorithm started.</p>
821:
822: <p>The <a href="webappapis.html#concept-task" title="concept-task">task</a> that the
823: <a href="webappapis.html#networking-task-source">networking task source</a> places on the <a href="webappapis.html#task-queue">task
824: queue</a> once the <a href="fetching-resources.html#fetch" title="fetch">fetching
825: algorithm</a> has completed must run the following steps:</p>
826:
827: <ol><li><p>If the element is not now the first element in the
828: <a href="#list-of-scripts-that-will-execute-in-order-as-soon-as-possible">list of scripts that will execute in order as soon as
829: possible</a> to which it was added above, then mark the
830: element as ready but abort these steps without executing the
831: script yet.</p></li>
832:
1.40 mike 833: <li><p><i>Execution</i>: <a href="#execute-the-script-block">Execute the script block</a>
834: corresponding to the first script element in this <a href="#list-of-scripts-that-will-execute-in-order-as-soon-as-possible">list of
835: scripts that will execute in order as soon as
836: possible</a>.</p></li>
1.39 mike 837:
838: <li><p>Remove the first element from this <a href="#list-of-scripts-that-will-execute-in-order-as-soon-as-possible">list of scripts
839: that will execute in order as soon as possible</a>.</p></li>
840:
841: <li><p>If this <a href="#list-of-scripts-that-will-execute-in-order-as-soon-as-possible">list of scripts that will execute in order
842: as soon as possible</a> is still not empty and the first
843: entry has already been marked as ready, then jump back to the
844: step labeled <i>execution</i>.</p></li>
845:
846: </ol></dd>
847:
848:
1.1 mike 849: <dt id="script-processing-src">If the element has a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute</dt>
850:
851: <dd>
852:
853: <p>The element must be added to the <dfn id="set-of-scripts-that-will-execute-as-soon-as-possible">set of scripts that
1.20 mike 854: will execute as soon as possible</dfn> of the
1.50 mike 855: <code><a href="infrastructure.html#document">Document</a></code> of the <code><a href="#the-script-element">script</a></code> element at the
1.40 mike 856: time the <a href="#prepare-a-script">prepare a script</a> algorithm started.</p>
1.1 mike 857:
858: <p>The <a href="webappapis.html#concept-task" title="concept-task">task</a> that the
859: <a href="webappapis.html#networking-task-source">networking task source</a> places on the <a href="webappapis.html#task-queue">task
860: queue</a> once the <a href="fetching-resources.html#fetch" title="fetch">fetching
1.40 mike 861: algorithm</a> has completed must <a href="#execute-the-script-block">execute the script
862: block</a> and then remove the element from the <a href="#set-of-scripts-that-will-execute-as-soon-as-possible">set of
863: scripts that will execute as soon as possible</a>.</p>
1.1 mike 864:
865: </dd>
866:
867:
868: <dt id="script-processing-inline">Otherwise</dt>
869:
1.40 mike 870: <dd>The user agent must immediately <a href="#execute-the-script-block">execute the script
871: block</a>, even if other scripts are already executing.</dd>
1.1 mike 872:
873: </dl></li>
874:
1.48 mike 875: </ol><p>Fetching an external script must <a href="the-end.html#delay-the-load-event">delay the load
1.1 mike 876: event</a> of the element's document until the <a href="webappapis.html#concept-task" title="concept-task">task</a> that is <a href="webappapis.html#queue-a-task" title="queue a
877: task">queued</a> by the <a href="webappapis.html#networking-task-source">networking task source</a> once
878: the resource has been <a href="fetching-resources.html#fetch" title="fetch">fetched</a> (defined
879: above) has been run.</p>
880:
1.20 mike 881: <p>The <dfn id="pending-parsing-blocking-script">pending parsing-blocking script</dfn> of a
882: <code><a href="infrastructure.html#document">Document</a></code> is used by the <code><a href="infrastructure.html#document">Document</a></code>'s
883: parser(s).</p>
1.1 mike 884:
1.50 mike 885: <p class="note">If a <code><a href="#the-script-element">script</a></code> element that blocks a
1.26 mike 886: parser gets moved to another <code><a href="infrastructure.html#document">Document</a></code> before it would
887: normally have stopped blocking that parser, it nonetheless continues
888: blocking that parser until the condition that causes it to be
889: blocking the parser no longer applies (e.g. if the script is a
890: <a href="#pending-parsing-blocking-script">pending parsing-blocking script</a> because there was
891: <a href="semantics.html#a-style-sheet-that-is-blocking-scripts">a style sheet that is blocking scripts</a> when it was
892: parsed, but then the script is moved to another
893: <code><a href="infrastructure.html#document">Document</a></code> before the style sheet loads, the script still
894: blocks the parser until the style sheets are all loaded, at which
895: time the script executes and the parser is unblocked).</p>
896:
1.48 mike 897:
1.40 mike 898: <p>When the user agent is required to <dfn id="execute-the-script-block" title="execute the script
899: block">execute a script block</dfn>, it must run the following
900: steps:</p>
901:
902: <ol><li>
903:
904: <p>If the element is flagged as <a href="#parser-inserted">"parser-inserted"</a>,
905: but the element's <code><a href="infrastructure.html#document">Document</a></code> is not the
906: <code><a href="infrastructure.html#document">Document</a></code> of the parser that created the element, then
907: abort these steps.</p>
1.1 mike 908:
1.40 mike 909: </li>
910:
911: <li>
1.1 mike 912:
1.40 mike 913: <p>Jump to the appropriate set of steps from the list below:</p>
1.1 mike 914:
1.40 mike 915: <dl class="switch"><dt>If the load resulted in an error (for example a DNS error, or
916: an HTTP 404 error)</dt>
1.1 mike 917:
1.40 mike 918: <dd><p>Executing the script block must just consist of <a href="webappapis.html#fire-a-simple-event" title="fire a simple event">firing a simple event</a> named
919: <code title="event-error">error</code> at the element.</p></dd>
920:
921: <dt>If the load was successful</dt>
922:
923: <!-- SCRIPT EXEC -->
924: <dd>
925:
1.43 mike 926: <p>Executing the script block must consist of running the
1.40 mike 927: following steps. For the purposes of these steps, the script is
928: considered to be from an <i>external file</i> if, while the
929: <a href="#prepare-a-script">prepare a script</a> algorithm above was running for
1.50 mike 930: this script, the <code><a href="#the-script-element">script</a></code> element had a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute specified.</p>
1.1 mike 931:
1.40 mike 932: <ol><li id="establish-script-block-source">
1.27 mike 933:
1.40 mike 934: <p>Initialize <dfn id="the-script-block-s-source"><var>the script block's source</var></dfn>
935: as follows:</p>
1.1 mike 936:
1.40 mike 937: <dl class="switch"><dt>If the script is from an external file and <var><a href="#the-script-block-s-type">the
938: script block's type</a></var> is a text-based language</dt>
1.1 mike 939:
1.40 mike 940: <dd>
1.1 mike 941:
1.40 mike 942: <p>The contents of that file, interpreted as string of
943: Unicode characters, are the script source.</p>
1.1 mike 944:
1.40 mike 945: <p>To obtain the string of Unicode characters, the user
946: agent run the following steps:</p>
1.1 mike 947:
1.40 mike 948: <ol><li><p>If the resource's <a href="fetching-resources.html#content-type" title="Content-Type">Content
949: Type metadata</a>, if any, specifies a character
950: encoding, and the user agent supports that encoding, then
951: let <var title="">character encoding</var> be that
952: encoding, and jump to the bottom step in this series of
953: steps.</p></li>
1.1 mike 954:
1.40 mike 955: <li><p>If the algorithm above set <var><a href="#the-script-block-s-character-encoding">the script block's
956: character encoding</a></var>, then let <var title="">character
957: encoding</var> be that encoding, and jump to the bottom
958: step in this series of steps.</p></li>
1.23 mike 959:
1.40 mike 960: <li><p>For each of the rows in the following table,
961: starting with the first one and going down, if the file has
962: as many or more bytes available than the number of bytes in
963: the first column, and the first bytes of the file match the
964: bytes given in the first column, then set <var title="">character encoding</var> to the encoding given in
965: the cell in the second column of that row, and jump to the
966: bottom step in this series of steps:</p>
1.23 mike 967:
1.48 mike 968:
1.40 mike 969: <table id="table-script-bom"><thead><tr><th>Bytes in Hexadecimal
970: </th><th>Encoding
1.48 mike 971: </th></tr></thead><tbody><tr><td>FE FF
1.40 mike 972: </td><td>Big-endian UTF-16
973: </td></tr><tr><td>FF FE
974: </td><td>Little-endian UTF-16
975: </td></tr><tr><td>EF BB BF
976: </td><td>UTF-8
1.48 mike 977: </td></tr></tbody></table><p class="note">This step looks for Unicode Byte Order
1.40 mike 978: Marks (BOMs).</p>
1.23 mike 979:
1.40 mike 980: </li>
1.23 mike 981:
1.40 mike 982: <li><p>Let <var title="">character encoding</var> be
983: <var><a href="#the-script-block-s-fallback-character-encoding">the script block's fallback character
984: encoding</a></var>.</p></li>
1.23 mike 985:
1.40 mike 986: <li><p>Convert the file to Unicode using <var>character
987: encoding</var>, following the rules for doing so given by
988: the specification for <var><a href="#the-script-block-s-type">the script block's
989: type</a></var>.</p></li>
1.23 mike 990:
1.40 mike 991: </ol></dd>
1.23 mike 992:
1.40 mike 993: <dt>If the script is from an external file and <var><a href="#the-script-block-s-type">the
994: script block's type</a></var> is an XML-based language</dt>
1.1 mike 995:
1.40 mike 996: <dd>
1.1 mike 997:
1.40 mike 998: <p>The external file is the script source. When it is later
999: executed, it must be interpreted in a manner consistent with
1000: the specification defining the language given by <var><a href="#the-script-block-s-type">the
1001: script block's type</a></var>.</p>
1.1 mike 1002:
1.40 mike 1003: </dd>
1.1 mike 1004:
1.40 mike 1005: <dt>If the script is inline and <var><a href="#the-script-block-s-type">the script block's
1006: type</a></var> is a text-based language</dt>
1.1 mike 1007:
1.40 mike 1008: <dd>
1.1 mike 1009:
1.40 mike 1010: <p>The value of the <code title="dom-script-text"><a href="#dom-script-text">text</a></code> IDL attribute at the
1011: time the element's <a href="#already-started">"already started"</a> flag was
1012: last set is the script source.</p>
1.1 mike 1013:
1.40 mike 1014: </dd>
1.1 mike 1015:
1.40 mike 1016: <dt>If the script is inline and <var><a href="#the-script-block-s-type">the script block's
1017: type</a></var> is an XML-based language</dt>
1.1 mike 1018:
1.40 mike 1019: <dd>
1.1 mike 1020:
1.50 mike 1021: <p>The child nodes of the <code><a href="#the-script-element">script</a></code> element at the
1.40 mike 1022: time the element's <a href="#already-started">"already started"</a> flag was
1023: last set are the script source.</p>
1.1 mike 1024:
1.40 mike 1025: </dd>
1.1 mike 1026:
1.40 mike 1027: </dl></li>
1.1 mike 1028:
1.40 mike 1029: <li>
1.1 mike 1030:
1.40 mike 1031: <p>If the script is from an external file, then increment the
1032: <a href="apis-in-html-documents.html#ignore-destructive-writes-counter">ignore-destructive-writes counter</a> of the
1.50 mike 1033: <code><a href="#the-script-element">script</a></code> element's <code><a href="infrastructure.html#document">Document</a></code>. Let <var title="">neutralized doc</var> be that
1.40 mike 1034: <code><a href="infrastructure.html#document">Document</a></code>.</p>
1.1 mike 1035:
1.40 mike 1036: </li>
1.7 mike 1037:
1.40 mike 1038: <li>
1.7 mike 1039:
1.40 mike 1040: <p><a href="webappapis.html#create-a-script-from-a-node" title="create a script from a node">Create a
1.50 mike 1041: script</a> from the <code><a href="#the-script-element">script</a></code> element node, using
1.40 mike 1042: <var><a href="#the-script-block-s-source">the script block's source</a></var> and <var><a href="#the-script-block-s-type">the script
1043: block's type</a></var>.</p>
1.7 mike 1044:
1.40 mike 1045: <p class="note">This is where the script is compiled and
1046: actually executed.</p>
1.1 mike 1047:
1.40 mike 1048: </li>
1.1 mike 1049:
1.40 mike 1050: <li>
1.1 mike 1051:
1.40 mike 1052: <p>Decrement the <a href="apis-in-html-documents.html#ignore-destructive-writes-counter">ignore-destructive-writes
1053: counter</a> of <var title="">neutralized doc</var>, if it
1054: was incremented in the earlier step.</p>
1.1 mike 1055:
1.40 mike 1056: </li>
1.7 mike 1057:
1.40 mike 1058: <li>
1.7 mike 1059:
1.40 mike 1060: <p>If the script is from an external file, <a href="webappapis.html#fire-a-simple-event">fire a simple
1061: event</a> named <code title="event-load">load</code> at the
1.50 mike 1062: <code><a href="#the-script-element">script</a></code> element.</p>
1.7 mike 1063:
1.40 mike 1064: <p>Otherwise, the script is internal; <a href="webappapis.html#queue-a-task">queue a
1.50 mike 1065: task</a> to <a href="webappapis.html#fire-a-simple-event">fire a simple event</a> named <code title="event-load">load</code> at the <code><a href="#the-script-element">script</a></code>
1.40 mike 1066: element.</p>
1.1 mike 1067:
1.40 mike 1068: </li>
1.1 mike 1069:
1.40 mike 1070: </ol></dd>
1.1 mike 1071:
1.40 mike 1072: </dl></li>
1.1 mike 1073:
1.40 mike 1074: </ol><p>The IDL attributes <dfn id="dom-script-src" title="dom-script-src"><code>src</code></dfn>, <dfn id="dom-script-type" title="dom-script-type"><code>type</code></dfn>, <dfn id="dom-script-charset" title="dom-script-charset"><code>charset</code></dfn>, and <dfn id="dom-script-defer" title="dom-script-defer"><code>defer</code></dfn>, each must
1.1 mike 1075: <a href="common-dom-interfaces.html#reflect">reflect</a> the respective content attributes of the same
1076: name.</p>
1077:
1.39 mike 1078: <p>The <dfn id="dom-script-async" title="dom-script-async"><code>async</code></dfn> IDL
1079: attribute controls whether the element will execute asynchronously
1080: or not. If the element's <a href="#force-async">"force-async"</a> flag is set,
1081: then, on getting, the <code title="dom-script-async"><a href="#dom-script-async">async</a></code>
1082: IDL attribute must return true, and on setting, the
1083: <a href="#force-async">"force-async"</a> flag must first be unset, and then the
1084: content attribute must be removed if the IDL attribute's new value
1085: is false, and must be set to the empty string if the IDL attribute's
1086: new value is true. If the element's <a href="#force-async">"force-async"</a> flag
1087: is <em>not</em> set, the IDL attribute must <a href="common-dom-interfaces.html#reflect">reflect</a> the
1088: <code title="attr-script-async"><a href="#attr-script-async">async</a></code> content attribute.</p>
1089:
1.1 mike 1090: </div><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>
1091:
1092: <dd>
1093:
1094: <p>Returns the contents of the element, ignoring child nodes that
1095: aren't <a href="infrastructure.html#text-node" title="text node">text nodes</a>.</p>
1096:
1097: <p>Can be set, to replace the element's children with the given
1098: value.</p>
1099:
1100: </dd>
1101:
1102: </dl><div class="impl">
1103:
1104: <p>The IDL attribute <dfn id="dom-script-text" title="dom-script-text"><code>text</code></dfn> must return a
1105: concatenation of the contents of all the <a href="infrastructure.html#text-node" title="text
1106: node">text nodes</a> that are direct children of the
1.50 mike 1107: <code><a href="#the-script-element">script</a></code> element (ignoring any other nodes such as
1.1 mike 1108: comments or elements), in tree order. On setting, it must act the
1109: same way as the <code><a href="infrastructure.html#textcontent">textContent</a></code> IDL attribute.</p>
1110:
1111: </div><p class="note">When inserted using the <code title="dom-document-write"><a href="apis-in-html-documents.html#dom-document-write">document.write()</a></code> method,
1.50 mike 1112: <code><a href="#the-script-element">script</a></code> elements execute (typically synchronously), but
1.1 mike 1113: 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
1114: execute at all.</p><div class="example">
1115:
1.50 mike 1116: <p>In this example, two <code><a href="#the-script-element">script</a></code> elements are used. One
1.1 mike 1117: embeds an external script, and the other includes some data.</p>
1118:
1119: <pre><script src="game-engine.js"></script>
1120: <script type="text/x-game-map">
1121: ........U.........e
1122: o............A....e
1123: .....A.....AAA....e
1124: .A..AAA...AAAAA...e
1125: </script></pre>
1126:
1127: <p>The data in this case might be used by the script to generate
1128: the map of a video game. The data doesn't have to be used that way,
1129: though; maybe the map data is actually embedded in other parts of
1130: the page's markup, and the data block here is just used by the
1131: site's search engine to help users who are looking for particular
1132: features in their game maps.</p>
1133:
1134: </div><div class="example">
1135:
1136: <p>The following sample shows how a script element can be used to
1137: define a function that is then used by other parts of the
1.50 mike 1138: document. It also shows how a <code><a href="#the-script-element">script</a></code> element can be
1.1 mike 1139: used to invoke script while the document is being parsed, in this
1140: case to initialize the form's output.</p>
1141:
1142: <pre><script>
1143: function calculate(form) {
1144: var price = 52000;
1145: if (form.elements.brakes.checked)
1146: price += 1000;
1147: if (form.elements.radio.checked)
1148: price += 2500;
1149: if (form.elements.turbo.checked)
1150: price += 5000;
1151: if (form.elements.sticker.checked)
1152: price += 250;
1153: form.elements.result.value = price;
1154: }
1155: </script>
1.52 mike 1156: <form name="pricecalc" onsubmit="return false" onchange="calculate(this)">
1.1 mike 1157: <fieldset>
1158: <legend>Work out the price of your car</legend>
1159: <p>Base cost: £52000.</p>
1160: <p>Select additional options:</p>
1.52 mike 1161: <ul>
1.1 mike 1162: <li><label><input type=checkbox name=brakes> Ceramic brakes (£1000)</label></li>
1163: <li><label><input type=checkbox name=radio> Satellite radio (£2500)</label></li>
1164: <li><label><input type=checkbox name=turbo> Turbo charger (£5000)</label></li>
1165: <li><label><input type=checkbox name=sticker> "XZ" sticker (£250)</label></li>
1166: </ul>
1.42 mike 1167: <p>Total: £<output name=result></output></p>
1.1 mike 1168: </fieldset>
1169: <script>
1.42 mike 1170: calculate(document.forms.pricecalc);
1.1 mike 1171: </script>
1172: </form></pre>
1173:
1.15 mike 1174: </div><h5 id="scriptingLanguages"><span class="secno">4.3.1.1 </span>Scripting languages</h5><div class="impl">
1.1 mike 1175:
1176: <p>A user agent is said to <dfn id="support-the-scripting-language">support the scripting language</dfn>
1177: if <var><a href="#the-script-block-s-type">the script block's type</a></var> is an <a href="infrastructure.html#ascii-case-insensitive">ASCII
1178: case-insensitive</a> match for the <a href="infrastructure.html#mime-type">MIME type</a> string
1179: of a scripting language that the user agent implements.</p>
1180:
1181: </div><p>The following lists some <a href="infrastructure.html#mime-type">MIME type</a> strings and the
1182: languages to which they refer:</p><dl><dt>"<code>application/ecmascript</code>"</dt>
1183: <dt>"<code>application/javascript</code>"</dt>
1184: <dt>"<code>application/x-ecmascript</code>"</dt>
1185: <dt>"<code>application/x-javascript</code>"</dt>
1186: <dt>"<code>text/ecmascript</code>"</dt>
1187: <dt>"<code>text/javascript</code>"</dt>
1188: <dt>"<code>text/javascript1.0</code>"</dt>
1189: <dt>"<code>text/javascript1.1</code>"</dt>
1190: <dt>"<code>text/javascript1.2</code>"</dt>
1191: <dt>"<code>text/javascript1.3</code>"</dt>
1192: <dt>"<code>text/javascript1.4</code>"</dt>
1193: <dt>"<code>text/javascript1.5</code>"</dt>
1194: <dt>"<code>text/jscript</code>"</dt>
1195: <dt>"<code>text/livescript</code>"</dt>
1196: <dt>"<code>text/x-ecmascript</code>"</dt>
1197: <dt>"<code>text/x-javascript</code>"</dt>
1198: <dd>JavaScript. <a href="references.html#refsECMA262">[ECMA262]</a></dd>
1199:
1200: <dt>"<code>text/javascript;e4x=1</code>"</dt>
1201: <dd>JavaScript with ECMAScript for XML. <a href="references.html#refsECMA357">[ECMA357]</a></dd>
1202:
1203: </dl><div class="impl">
1204:
1205: <p>User agents may support other <a href="infrastructure.html#mime-type" title="MIME type">MIME
1206: types</a> and other languages.</p>
1207:
1.48 mike 1208:
1.1 mike 1209: <p>When examining types to determine if they support the language,
1210: user agents must not ignore unknown MIME parameters — types
1211: with unknown parameters must be assumed to be unsupported. The <code title="">charset</code> parameter must be treated as an unknown
1212: parameter for the purpose of comparing <a href="infrastructure.html#mime-type" title="MIME type">MIME
1213: types</a> here.</p>
1214:
1.50 mike 1215: </div><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>The <code><a href="infrastructure.html#textcontent">textContent</a></code> of a <code><a href="#the-script-element">script</a></code> element
1.37 mike 1216: must match the <code title="">script</code> production in the
1217: following ABNF, the character set for which is Unicode. <a href="references.html#refsABNF">[ABNF]</a></p><pre>script = data1 *( escape [ script-start data3 ] "-->" data1 ) [ escape ]
1.1 mike 1218: escape = "<!--" data2 *( script-start data3 script-end data2 )
1219:
1220: data1 = <any string that doesn't contain a substring that matches not-data1>
1.48 mike 1221: not-data1 = "<!--"
1.1 mike 1222:
1223: data2 = <any string that doesn't contain a substring that matches not-data2>
1.48 mike 1224: not-data2 = script-start / "-->"
1.1 mike 1225:
1226: data3 = <any string that doesn't contain a substring that matches not-data3>
1227: not-data3 = script-end / "-->"
1228:
1229: script-start = lt s c r i p t tag-end
1230: script-end = lt slash s c r i p t tag-end
1231:
1232: lt = %x003C ; U+003C LESS-THAN SIGN character (<)
1233: slash = %x002F ; U+002F SOLIDUS character (/)
1234:
1235: s = %x0053 ; U+0053 LATIN CAPITAL LETTER S
1236: s =/ %x0073 ; U+0073 LATIN SMALL LETTER S
1237: c = %x0043 ; U+0043 LATIN CAPITAL LETTER C
1238: c =/ %x0063 ; U+0063 LATIN SMALL LETTER C
1239: r = %x0052 ; U+0052 LATIN CAPITAL LETTER R
1240: r =/ %x0072 ; U+0072 LATIN SMALL LETTER R
1241: i = %x0049 ; U+0049 LATIN CAPITAL LETTER I
1242: i =/ %x0069 ; U+0069 LATIN SMALL LETTER I
1243: p = %x0050 ; U+0050 LATIN CAPITAL LETTER P
1244: p =/ %x0070 ; U+0070 LATIN SMALL LETTER P
1245: t = %x0054 ; U+0054 LATIN CAPITAL LETTER T
1246: t =/ %x0074 ; U+0074 LATIN SMALL LETTER T
1247:
1.53 ! mike 1248: tag-end = %x0009 ; U+0009 CHARACTER TABULATION (tab)
1.1 mike 1249: tag-end =/ %x000A ; U+000A LINE FEED (LF)
1250: tag-end =/ %x000C ; U+000C FORM FEED (FF)
1251: tag-end =/ %x0020 ; U+0020 SPACE
1252: tag-end =/ %x002F ; U+002F SOLIDUS (/)
1.50 mike 1253: tag-end =/ %x003E ; U+003E GREATER-THAN SIGN (>)</pre><p>When a <code><a href="#the-script-element">script</a></code> element contains <a href="#inline-documentation-for-external-scripts">script
1.1 mike 1254: documentation</a>, there are further restrictions on the contents
1.50 mike 1255: 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>If a <code><a href="#the-script-element">script</a></code> element's <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute is specified, then the
1256: contents of the <code><a href="#the-script-element">script</a></code> element, if any, must be such
1.1 mike 1257: that the value of the <code title="dom-script-text"><a href="#dom-script-text">text</a></code> IDL
1258: attribute, which is derived from the element's contents, matches the
1259: <code title="">documentation</code> production in the following
1260: ABNF, the character set for which is Unicode. <a href="references.html#refsABNF">[ABNF]</a></p><pre>documentation = *( *( space / tab / comment ) [ line-comment ] newline )
1261: comment = slash star *( not-star / star not-slash ) 1*star slash
1262: line-comment = slash slash *not-newline
1263:
1264: ; characters
1.53 ! mike 1265: tab = %x0009 ; U+0009 CHARACTER TABULATION (tab)
1.1 mike 1266: newline = %x000A ; U+000A LINE FEED (LF)
1267: space = %x0020 ; U+0020 SPACE
1268: star = %x002A ; U+002A ASTERISK (*)
1269: slash = %x002F ; U+002F SOLIDUS (/)
1270: not-newline = %x0000-0009 / %x000B-10FFFF
1271: ; a Unicode character other than U+000A LINE FEED (LF)
1272: not-star = %x0000-0029 / %x002B-10FFFF
1273: ; a Unicode character other than U+002A ASTERISK (*)
1274: not-slash = %x0000-002E / %x0030-10FFFF
1275: ; a Unicode character other than U+002F SOLIDUS (/)</pre><p class="note">This corresponds to putting the contents of the
1276: element in JavaScript comments.</p><p class="note">This requirement is in addition to the earlier
1.50 mike 1277: restrictions on the syntax of contents of <code><a href="#the-script-element">script</a></code>
1.1 mike 1278: elements.</p><div class="example">
1279:
1280: <p>This allows authors to include documentation, such as license
1281: information or API information, inside their documents while still
1282: referring to external script files. The syntax is constrained so
1283: that authors don't accidentally include what looks like valid
1284: script while also providing a <code title="attr-script-src"><a href="#attr-script-src">src</a></code> attribute.</p>
1285:
1286: <pre><script src="cool-effects.js">
1287: // create new instances using:
1288: // var e = new Effect();
1289: // start the effect using .play, stop using .stop:
1290: // e.play();
1291: // e.stop();
1292: </script></pre>
1293:
1.49 mike 1294: </div><div class="impl">
1295:
1.50 mike 1296: <h5 id="scriptTagXSLT"><span class="secno">4.3.1.4 </span>Interaction of <code><a href="#the-script-element">script</a></code> elements and XSLT</h5>
1.49 mike 1297:
1298: <p><i>This section is non-normative.</i></p>
1299:
1300: <p>This specification does not define how XSLT interacts with the
1.50 mike 1301: <code><a href="#the-script-element">script</a></code> element (or, indeed, how XSLT processing
1.49 mike 1302: triggers the <a href="the-end.html#stop-parsing">stop parsing</a> steps, how it interacts with
1303: the <a href="history.html#navigate" title="navigate">navigation</a> algorithm, or how it
1304: fits in with the <a href="webappapis.html#event-loop">event loop</a>). However, in the absence
1305: of another specification actually defining this, here are some
1306: guidelines for implementors, based on existing implementations:</p>
1307:
1308: <ul><li><p>When an XSLT transformation program is triggered by an <code title=""><?xml-stylesheet?></code> processing instruction and
1309: the browser implements a direct-to-DOM transformation,
1.50 mike 1310: <code><a href="#the-script-element">script</a></code> elements created by the XSLT processor need to
1.49 mike 1311: be marked <a href="#parser-inserted">"parser-inserted"</a> and run in document order
1312: (modulo scripts marked <code title="attr-script-defer"><a href="#attr-script-defer">defer</a></code>
1313: or <code title="attr-script-async"><a href="#attr-script-async">async</a></code>), asynchronously
1314: while the transformation is occurring.</p></li>
1315:
1316: <li><p>The <code title="dom-XSLTProcessor-transformToDocument">XSLTProcessor.transformToDocument()</code>
1317: method adds elements to a <code><a href="infrastructure.html#document">Document</a></code> that is not in a
1318: <a href="browsers.html#browsing-context">browsing context</a>, and, accordingly, any
1.50 mike 1319: <code><a href="#the-script-element">script</a></code> elements they create need to have their
1.49 mike 1320: <a href="#already-started">"already started"</a> flag set in the <a href="#prepare-a-script">prepare a
1321: script</a> algorithm and never get executed (<a href="webappapis.html#concept-bc-noscript" title="concept-bc-noscript">scripting is disabled</a>). Such
1.50 mike 1322: <code><a href="#the-script-element">script</a></code> elements still need to be marked
1.49 mike 1323: <a href="#parser-inserted">"parser-inserted"</a>, though, such that their <code title="dom-script-async"><a href="#dom-script-async">async</a></code> IDL attribute will return
1324: false in the absence of an <code title="attr-script-async"><a href="#attr-script-async">async</a></code> content attribute.</p></li>
1325:
1326: <li><p>The <code title="dom-XSLTProcessor-transformToFragment">XSLTProcessor.transformToFragment()</code>
1327: method needs to create a fragment that is equivalent to one built
1328: manually by creating the elements using <code title="dom-document-createElementNS"><a href="infrastructure.html#dom-document-createelementns">document.createElementNS()</a></code>.
1.50 mike 1329: For instance, it needs to create <code><a href="#the-script-element">script</a></code> elements that
1.49 mike 1330: aren't <a href="#parser-inserted">"parser-inserted"</a> and that don't have their
1331: <a href="#already-started">"already started"</a> flag set, so that they will execute
1332: when the fragment is inserted into a document.</p></li>
1333:
1334: </ul><p>The main distinction between the first two cases and the last
1335: case is that the first two operate on <code><a href="infrastructure.html#document">Document</a></code>s and the
1336: last operates on a fragment.</p>
1337:
1.22 mike 1338: </div><h4 id="the-noscript-element"><span class="secno">4.3.2 </span>The <dfn><code>noscript</code></dfn> element</h4><dl class="element"><dt>Categories</dt>
1.1 mike 1339: <dd><a href="content-models.html#metadata-content">Metadata content</a>.</dd>
1340: <dd><a href="content-models.html#flow-content">Flow content</a>.</dd>
1341: <dd><a href="content-models.html#phrasing-content">Phrasing content</a>.</dd>
1.16 mike 1342: <dt>Contexts in which this element can be used:</dt>
1.50 mike 1343: <dd>In a <code><a href="semantics.html#the-head-element">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>
1.1 mike 1344: <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>
1345: <dt>Content model:</dt>
1.50 mike 1346: <dd>When <a href="webappapis.html#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a>, in a <code><a href="semantics.html#the-head-element">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#the-meta-element">meta</a></code> elements.</dd>
1347: <dd>When <a href="webappapis.html#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a>, not in a <code><a href="semantics.html#the-head-element">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>
1.1 mike 1348: <dd>Otherwise: text that conforms to the requirements given in the prose.</dd>
1349: <dt>Content attributes:</dt>
1350: <dd><a href="elements.html#global-attributes">Global attributes</a></dd>
1351: <dt>DOM interface:</dt>
1352: <dd>Uses <code><a href="elements.html#htmlelement">HTMLElement</a></code>.</dd>
1353: </dl><p>The <code><a href="#the-noscript-element">noscript</a></code> element <a href="rendering.html#represents">represents</a> nothing
1354: if <a href="webappapis.html#concept-n-script" title="concept-n-script">scripting is enabled</a>, and
1355: <a href="rendering.html#represents">represents</a> its children if <a href="webappapis.html#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a>. It is used
1356: to present different markup to user agents that support scripting
1357: and those that don't support scripting, by affecting how the
1358: document is parsed.</p><p>When used in <a href="dom.html#html-documents">HTML documents</a>, the allowed content
1.50 mike 1359: model is as follows:</p><dl><dt>In a <code><a href="semantics.html#the-head-element">head</a></code> element, if <a href="webappapis.html#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a> for the
1.1 mike 1360: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
1361:
1362: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only
1.50 mike 1363: <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#the-meta-element">meta</a></code>
1.1 mike 1364: elements.</p></dd>
1365:
1.50 mike 1366: <dt>In a <code><a href="semantics.html#the-head-element">head</a></code> element, if <a href="webappapis.html#concept-n-script" title="concept-n-script">scripting is enabled</a> for the
1.1 mike 1367: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
1368:
1369: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only text,
1370: except that invoking the <a href="the-end.html#html-fragment-parsing-algorithm">HTML fragment parsing
1.48 mike 1371: algorithm</a> with
1.51 mike 1372: the <code><a href="#the-noscript-element">noscript</a></code> element as the <var title="concept-frag-parse-context"><a href="the-end.html#concept-frag-parse-context">context</a></var> element and the
1373: text contents as the <var title="">input</var> must result in a
1374: list of nodes that consists only of <code><a href="semantics.html#the-link-element">link</a></code>,
1375: <code><a href="semantics.html#the-style-element">style</a></code>, and <code><a href="semantics.html#the-meta-element">meta</a></code> elements that would be
1376: conforming if they were children of the <code><a href="#the-noscript-element">noscript</a></code>
1377: element, and no <a href="parsing.html#parse-error" title="parse error">parse
1378: errors</a>.</p></dd>
1.1 mike 1379:
1.50 mike 1380: <dt>Outside of <code><a href="semantics.html#the-head-element">head</a></code> elements, if <a href="webappapis.html#concept-n-noscript" title="concept-n-noscript">scripting is disabled</a> for the
1.1 mike 1381: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
1382:
1383: <dd><p>The <code><a href="#the-noscript-element">noscript</a></code> element's content model is
1384: <a href="content-models.html#transparent">transparent</a>, with the additional restriction that a
1385: <code><a href="#the-noscript-element">noscript</a></code> element must not have a <code><a href="#the-noscript-element">noscript</a></code>
1386: element as an ancestor (that is, <code><a href="#the-noscript-element">noscript</a></code> can't be
1387: nested).</p></dd>
1388:
1.50 mike 1389: <dt>Outside of <code><a href="semantics.html#the-head-element">head</a></code> elements, if <a href="webappapis.html#concept-n-script" title="concept-n-script">scripting is enabled</a> for the
1.1 mike 1390: <code><a href="#the-noscript-element">noscript</a></code> element</dt>
1391:
1392: <dd>
1393:
1394: <p>The <code><a href="#the-noscript-element">noscript</a></code> element must contain only text,
1395: except that the text must be such that running the following
1396: algorithm results in a conforming document with no
1.50 mike 1397: <code><a href="#the-noscript-element">noscript</a></code> elements and no <code><a href="#the-script-element">script</a></code>
1.1 mike 1398: elements, and such that no step in the algorithm causes an
1399: <a href="parsing.html#html-parser">HTML parser</a> to flag a <a href="parsing.html#parse-error">parse error</a>:</p>
1400:
1.50 mike 1401: <ol><li>Remove every <code><a href="#the-script-element">script</a></code> element from the
1.1 mike 1402: document.</li>
1403:
1404: <li>Make a list of every <code><a href="#the-noscript-element">noscript</a></code> element in the
1405: document. For every <code><a href="#the-noscript-element">noscript</a></code> element in that list,
1406: perform the following steps:
1407:
1408: <ol><li>Let the <var title="">parent element</var> be the parent
1409: element of the <code><a href="#the-noscript-element">noscript</a></code> element.</li>
1410:
1411: <li>Take all the children of the <var title="">parent element</var>
1412: that come before the <code><a href="#the-noscript-element">noscript</a></code> element, and call these
1413: elements <var title="">the before children</var>.</li>
1414:
1415: <li>Take all the children of the <var title="">parent element</var>
1416: that come <em>after</em> the <code><a href="#the-noscript-element">noscript</a></code> element, and
1417: call these elements <var title="">the after children</var>.</li>
1418:
1419: <li>Let <var title="">s</var> be the concatenation of all the
1420: <a href="infrastructure.html#text-node">text node</a> children of the <code><a href="#the-noscript-element">noscript</a></code>
1421: element.</li>
1422:
1423: <li>Set the <code title="dom-innerHTML"><a href="apis-in-html-documents.html#dom-innerhtml">innerHTML</a></code>
1424: attribute of the <var title="">parent element</var> to the value
1425: of <var title="">s</var>. (This, as a side-effect, causes the
1426: <code><a href="#the-noscript-element">noscript</a></code> element to be removed from the
1427: document.)</li>
1428:
1429: <li>Insert <var title="">the before children</var> at the start of
1430: the <var title="">parent element</var>, preserving their original
1431: relative order.</li>
1432:
1433: <li>Insert <var title="">the after children</var> at the end of the
1434: <var title="">parent element</var>, preserving their original
1435: relative order.</li>
1436:
1437: </ol></li>
1438:
1439: </ol></dd>
1440:
1441: </dl><p class="note">All these contortions are required because, for
1442: historical reasons, the <code><a href="#the-noscript-element">noscript</a></code> element is handled
1443: differently by the <a href="parsing.html#html-parser">HTML parser</a> based on whether <a href="parsing.html#scripting-flag" title="scripting flag">scripting was enabled or not</a> when the
1444: 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
1445: documents</a>.</p><p class="note"><strong>The <code><a href="#the-noscript-element">noscript</a></code> element is only
1446: effective in <a href="syntax.html#syntax">the HTML syntax</a>, it has no effect in
1447: <a href="the-xhtml-syntax.html#the-xhtml-syntax">the XHTML syntax</a>.</strong></p><div class="impl">
1448:
1449: <p>The <code><a href="#the-noscript-element">noscript</a></code> element has no other requirements. In
1450: particular, children of the <code><a href="#the-noscript-element">noscript</a></code> element are not
1451: exempt from <a href="association-of-controls-and-forms.html#form-submission">form submission</a>, scripting, and so forth,
1452: even when <a href="webappapis.html#concept-n-script" title="concept-n-script">scripting is enabled</a>
1453: for the element.</p>
1454:
1455: </div><div class="example">
1456:
1457: <p>In the following example, a <code><a href="#the-noscript-element">noscript</a></code> element is
1458: used to provide fallback for a script.</p>
1459:
1460: <pre><form action="calcSquare.php">
1461: <p>
1462: <label for=x>Number</label>:
1463: <input id="x" name="x" type="number">
1464: </p>
1465: <script>
1466: var x = document.getElementById('x');
1467: var output = document.createElement('p');
1468: output.textContent = 'Type a number; it will be squared right then!';
1469: x.form.appendChild(output);
1470: x.form.onsubmit = function () { return false; }
1471: x.oninput = function () {
1472: var v = x.valueAsNumber;
1473: output.textContent = v + ' squared is ' + v * v;
1474: };
1475: </script>
1476: <noscript>
1477: <input type=submit value="Calculate Square">
1478: </noscript>
1479: </form></pre>
1480:
1481: <p>When script is disabled, a button appears to do the calculation
1482: on the server side. When script is enabled, the value is computed
1483: on-the-fly instead.</p>
1484:
1485: <p>The <code><a href="#the-noscript-element">noscript</a></code> element is a blunt
1486: instrument. Sometimes, scripts might be enabled, but for some
1487: reason the page's script might fail. For this reason, it's
1488: generally better to avoid using <code><a href="#the-noscript-element">noscript</a></code>, and to
1489: instead design the script to change the page from being a
1490: scriptless page to a scripted page on the fly, as in the next
1491: example:</p>
1492:
1493: <pre><form action="calcSquare.php">
1494: <p>
1495: <label for=x>Number</label>:
1496: <input id="x" name="x" type="number">
1497: </p>
1498: <strong><input id="submit" type=submit value="Calculate Square"></strong>
1499: <script>
1500: var x = document.getElementById('x');
1501: var output = document.createElement('p');
1502: output.textContent = 'Type a number; it will be squared right then!';
1503: x.form.appendChild(output);
1504: x.form.onsubmit = function () { return false; }
1505: x.oninput = function () {
1506: var v = x.valueAsNumber;
1507: output.textContent = v + ' squared is ' + v * v;
1508: };
1509: <strong> var submit = document.getElementById('submit');
1510: submit.parentNode.removeChild(submit);</strong>
1511: </script>
1512: </form></pre>
1513:
1514: <p>The above technique is also useful in XHTML, since
1515: <code><a href="#the-noscript-element">noscript</a></code> is not supported in <a href="the-xhtml-syntax.html#the-xhtml-syntax">the XHTML
1516: syntax</a>.</p>
1517:
1518: </div></body></html>
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