Annotation of html5/spec/the-iframe-element.html, revision 1.291
1.233 mike 1: <!DOCTYPE html>
1.241 mike 2: <html lang="en-US-x-Hixie"><head><title>4.8.2 The iframe element — HTML5</title><link rel="stylesheet" href="alert.css"><style type="text/css">
1.1 mike 3: pre { margin-left: 2em; white-space: pre-wrap; }
4: h2 { margin: 3em 0 1em 0; }
5: h3 { margin: 2.5em 0 1em 0; }
6: h4 { margin: 2.5em 0 0.75em 0; }
7: h5, h6 { margin: 2.5em 0 1em; }
8: h1 + h2, h1 + h2 + h2 { margin: 0.75em 0 0.75em; }
9: h2 + h3, h3 + h4, h4 + h5, h5 + h6 { margin-top: 0.5em; }
10: p { margin: 1em 0; }
11: hr:not(.top) { display: block; background: none; border: none; padding: 0; margin: 2em 0; height: auto; }
12: dl, dd { margin-top: 0; margin-bottom: 0; }
13: dt { margin-top: 0.75em; margin-bottom: 0.25em; clear: left; }
14: dt + dt { margin-top: 0; }
15: dd dt { margin-top: 0.25em; margin-bottom: 0; }
16: dd p { margin-top: 0; }
17: dd dl + p { margin-top: 1em; }
18: dd table + p { margin-top: 1em; }
19: p + * > li, dd li { margin: 1em 0; }
20: dt, dfn { font-weight: bold; font-style: normal; }
1.83 mike 21: i, em { font-style: italic; }
1.1 mike 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; }
1.96 mike 43: img.extra, p.overview { float: right; }
1.94 mike 44: pre.idl { border: solid thin; background: #EEEEEE; color: black; padding: 0.5em 1em; position: relative; }
1.1 mike 45: pre.idl :link, pre.idl :visited { color: inherit; background: transparent; }
1.94 mike 46: pre.idl::before { content: "IDL"; font: bold small sans-serif; padding: 0.5em; background: white; position: absolute; top: 0; margin: -1px 0 0 -4em; width: 1.5em; border: thin solid; border-radius: 0 0 0 0.5em }
1.1 mike 47: pre.css { border: solid thin; background: #FFFFEE; color: black; padding: 0.5em 1em; }
48: pre.css:first-line { color: #AAAA50; }
49: dl.domintro { color: green; margin: 2em 0 2em 2em; padding: 0.5em 1em; border: none; background: #DDFFDD; }
50: hr + dl.domintro, div.impl + dl.domintro { margin-top: 2.5em; margin-bottom: 1.5em; }
51: dl.domintro dt, dl.domintro dt * { color: black; text-decoration: none; }
52: dl.domintro dd { margin: 0.5em 0 1em 2em; padding: 0; }
53: dl.domintro dd p { margin: 0.5em 0; }
1.124 mike 54: dl.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; }
1.1 mike 55: dl.switch { padding-left: 2em; }
56: dl.switch > dt { text-indent: -1.5em; }
57: dl.switch > dt:before { content: '\21AA'; padding: 0 0.5em 0 0; display: inline-block; width: 1em; text-align: right; line-height: 0.5em; }
58: dl.triple { padding: 0 0 0 1em; }
59: dl.triple dt, dl.triple dd { margin: 0; display: inline }
60: dl.triple dt:after { content: ':'; }
61: dl.triple dd:after { content: '\A'; white-space: pre; }
62: .diff-old { text-decoration: line-through; color: silver; background: transparent; }
63: .diff-chg, .diff-new { text-decoration: underline; color: green; background: transparent; }
64: a .diff-new { border-bottom: 1px blue solid; }
65:
66: h2 { page-break-before: always; }
67: h1, h2, h3, h4, h5, h6 { page-break-after: avoid; }
68: h1 + h2, hr + h2.no-toc { page-break-before: auto; }
69:
1.26 mike 70: p > span:not([title=""]):not([class="XXX"]):not([class="impl"]):not([class="note"]),
71: li > span:not([title=""]):not([class="XXX"]):not([class="impl"]):not([class="note"]), { border-bottom: solid #9999CC; }
1.1 mike 72:
73: div.head { margin: 0 0 1em; padding: 1em 0 0 0; }
74: div.head p { margin: 0; }
75: div.head h1 { margin: 0; }
76: div.head .logo { float: right; margin: 0 1em; }
77: div.head .logo img { border: none } /* remove border from top image */
78: div.head dl { margin: 1em 0; }
79: div.head p.copyright, div.head p.alt { font-size: x-small; font-style: oblique; margin: 0; }
80:
81: body > .toc > li { margin-top: 1em; margin-bottom: 1em; }
82: body > .toc.brief > li { margin-top: 0.35em; margin-bottom: 0.35em; }
83: body > .toc > li > * { margin-bottom: 0.5em; }
84: body > .toc > li > * > li > * { margin-bottom: 0.25em; }
85: .toc, .toc li { list-style: none; }
86:
87: .brief { margin-top: 1em; margin-bottom: 1em; line-height: 1.1; }
88: .brief li { margin: 0; padding: 0; }
89: .brief li p { margin: 0; padding: 0; }
90:
91: .category-list { margin-top: -0.75em; margin-bottom: 1em; line-height: 1.5; }
92: .category-list::before { content: '\21D2\A0'; font-size: 1.2em; font-weight: 900; }
93: .category-list li { display: inline; }
94: .category-list li:not(:last-child)::after { content: ', '; }
95: .category-list li > span, .category-list li > a { text-transform: lowercase; }
96: .category-list li * { text-transform: none; } /* don't affect <code> nested in <a> */
97:
98: .XXX { color: #E50000; background: white; border: solid red; padding: 0.5em; margin: 1em 0; }
99: .XXX > :first-child { margin-top: 0; }
100: p .XXX { line-height: 3em; }
101: .annotation { border: solid thin black; background: #0C479D; color: white; position: relative; margin: 8px 0 20px 0; }
102: .annotation:before { position: absolute; left: 0; top: 0; width: 100%; height: 100%; margin: 6px -6px -6px 6px; background: #333333; z-index: -1; content: ''; }
103: .annotation :link, .annotation :visited { color: inherit; }
104: .annotation :link:hover, .annotation :visited:hover { background: transparent; }
105: .annotation span { border: none ! important; }
106: .note { color: green; background: transparent; font-family: sans-serif; }
107: .warning { color: red; background: transparent; }
108: .note, .warning { font-weight: bolder; font-style: italic; }
1.83 mike 109: .note em, .warning em, .note i, .warning i { font-style: normal; }
1.1 mike 110: p.note, div.note { padding: 0.5em 2em; }
111: span.note { padding: 0 2em; }
112: .note p:first-child, .warning p:first-child { margin-top: 0; }
113: .note p:last-child, .warning p:last-child { margin-bottom: 0; }
114: .warning:before { font-style: normal; }
115: p.note:before { content: 'Note: '; }
116: p.warning:before { content: '\26A0 Warning! '; }
117:
118: .bookkeeping:before { display: block; content: 'Bookkeeping details'; font-weight: bolder; font-style: italic; }
119: .bookkeeping { font-size: 0.8em; margin: 2em 0; }
120: .bookkeeping p { margin: 0.5em 2em; display: list-item; list-style: square; }
1.12 mike 121: .bookkeeping dt { margin: 0.5em 2em 0; }
122: .bookkeeping dd { margin: 0 3em 0.5em; }
1.1 mike 123:
124: h4 { position: relative; z-index: 3; }
125: h4 + .element, h4 + div + .element { margin-top: -2.5em; padding-top: 2em; }
126: .element {
127: background: #EEEEFF;
128: color: black;
129: margin: 0 0 1em 0.15em;
130: padding: 0 1em 0.25em 0.75em;
131: border-left: solid #9999FF 0.25em;
132: position: relative;
133: z-index: 1;
134: }
135: .element:before {
136: position: absolute;
137: z-index: 2;
138: top: 0;
139: left: -1.15em;
140: height: 2em;
141: width: 0.9em;
142: background: #EEEEFF;
143: content: ' ';
144: border-style: none none solid solid;
145: border-color: #9999FF;
146: border-width: 0.25em;
147: }
148:
149: .example { display: block; color: #222222; background: #FCFCFC; border-left: double; margin-left: 2em; padding-left: 1em; }
150: td > .example:only-child { margin: 0 0 0 0.1em; }
151:
152: ul.domTree, ul.domTree ul { padding: 0 0 0 1em; margin: 0; }
153: ul.domTree li { padding: 0; margin: 0; list-style: none; position: relative; }
154: ul.domTree li li { list-style: none; }
155: 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; }
156: 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; }
157: ul.domTree span { font-style: italic; font-family: serif; }
158: ul.domTree .t1 code { color: purple; font-weight: bold; }
159: ul.domTree .t2 { font-style: normal; font-family: monospace; }
160: ul.domTree .t2 .name { color: black; font-weight: bold; }
161: ul.domTree .t2 .value { color: blue; font-weight: normal; }
162: ul.domTree .t3 code, .domTree .t4 code, .domTree .t5 code { color: gray; }
163: ul.domTree .t7 code, .domTree .t8 code { color: green; }
164: ul.domTree .t10 code { color: teal; }
165:
166: body.dfnEnabled dfn { cursor: pointer; }
167: .dfnPanel {
168: display: inline;
169: position: absolute;
170: z-index: 10;
171: height: auto;
172: width: auto;
173: padding: 0.5em 0.75em;
174: font: small sans-serif, Droid Sans Fallback;
175: background: #DDDDDD;
176: color: black;
177: border: outset 0.2em;
178: }
179: .dfnPanel * { margin: 0; padding: 0; font: inherit; text-indent: 0; }
180: .dfnPanel :link, .dfnPanel :visited { color: black; }
181: .dfnPanel p { font-weight: bolder; }
182: .dfnPanel * + p { margin-top: 0.25em; }
183: .dfnPanel li { list-style-position: inside; }
184:
185: #configUI { position: absolute; z-index: 20; top: 10em; right: 1em; width: 11em; font-size: small; }
186: #configUI p { margin: 0.5em 0; padding: 0.3em; background: #EEEEEE; color: black; border: inset thin; }
187: #configUI p label { display: block; }
188: #configUI #updateUI, #configUI .loginUI { text-align: center; }
189: #configUI input[type=button] { display: block; margin: auto; }
1.11 mike 190:
1.30 mike 191: fieldset { margin: 1em; padding: 0.5em 1em; }
192: fieldset > legend + * { margin-top: 0; }
1.21 mike 193: fieldset > :last-child { margin-bottom: 0; }
1.30 mike 194: fieldset p { margin: 0.5em 0; }
195:
1.259 mike 196: </style><link href="http://www.w3.org/StyleSheets/TR/W3C-ED" rel="stylesheet" type="text/css"><meta content="noindex" name="robots"><style type="text/css">
1.1 mike 197:
198: .applies thead th > * { display: block; }
199: .applies thead code { display: block; }
200: .applies tbody th { whitespace: nowrap; }
201: .applies td { text-align: center; }
202: .applies .yes { background: yellow; }
203:
1.14 mike 204: .matrix, .matrix td { border: hidden; text-align: right; }
1.1 mike 205: .matrix { margin-left: 2em; }
206:
207: .dice-example { border-collapse: collapse; border-style: hidden solid solid hidden; border-width: thin; margin-left: 3em; }
208: .dice-example caption { width: 30em; font-size: smaller; font-style: italic; padding: 0.75em 0; text-align: left; }
209: .dice-example td, .dice-example th { border: solid thin; width: 1.35em; height: 1.05em; text-align: center; padding: 0; }
210:
1.17 mike 211: td.eg { border-width: thin; text-align: center; }
212:
1.1 mike 213: #table-example-1 { border: solid thin; border-collapse: collapse; margin-left: 3em; }
214: #table-example-1 * { font-family: "Essays1743", serif; line-height: 1.01em; }
215: #table-example-1 caption { padding-bottom: 0.5em; }
216: #table-example-1 thead, #table-example-1 tbody { border: none; }
217: #table-example-1 th, #table-example-1 td { border: solid thin; }
218: #table-example-1 th { font-weight: normal; }
219: #table-example-1 td { border-style: none solid; vertical-align: top; }
220: #table-example-1 th { padding: 0.5em; vertical-align: middle; text-align: center; }
221: #table-example-1 tbody tr:first-child td { padding-top: 0.5em; }
222: #table-example-1 tbody tr:last-child td { padding-bottom: 1.5em; }
223: #table-example-1 tbody td:first-child { padding-left: 2.5em; padding-right: 0; width: 9em; }
224: #table-example-1 tbody td:first-child::after { content: leader(". "); }
225: #table-example-1 tbody td { padding-left: 2em; padding-right: 2em; }
226: #table-example-1 tbody td:first-child + td { width: 10em; }
227: #table-example-1 tbody td:first-child + td ~ td { width: 2.5em; }
228: #table-example-1 tbody td:first-child + td + td + td ~ td { width: 1.25em; }
229:
230: .apple-table-examples { border: none; border-collapse: separate; border-spacing: 1.5em 0em; width: 40em; margin-left: 3em; }
231: .apple-table-examples * { font-family: "Times", serif; }
232: .apple-table-examples td, .apple-table-examples th { border: none; white-space: nowrap; padding-top: 0; padding-bottom: 0; }
233: .apple-table-examples tbody th:first-child { border-left: none; width: 100%; }
234: .apple-table-examples thead th:first-child ~ th { font-size: smaller; font-weight: bolder; border-bottom: solid 2px; text-align: center; }
235: .apple-table-examples tbody th::after, .apple-table-examples tfoot th::after { content: leader(". ") }
236: .apple-table-examples tbody th, .apple-table-examples tfoot th { font: inherit; text-align: left; }
237: .apple-table-examples td { text-align: right; vertical-align: top; }
238: .apple-table-examples.e1 tbody tr:last-child td { border-bottom: solid 1px; }
239: .apple-table-examples.e1 tbody + tbody tr:last-child td { border-bottom: double 3px; }
240: .apple-table-examples.e2 th[scope=row] { padding-left: 1em; }
241: .apple-table-examples sup { line-height: 0; }
242:
243: .details-example img { vertical-align: top; }
244:
1.40 mike 245: #base64-table {
246: white-space: nowrap;
247: font-size: 0.6em;
248: column-width: 6em;
249: column-count: 5;
250: column-gap: 1em;
251: -moz-column-width: 6em;
252: -moz-column-count: 5;
253: -moz-column-gap: 1em;
254: -webkit-column-width: 6em;
255: -webkit-column-count: 5;
256: -webkit-column-gap: 1em;
257: }
258: #base64-table thead { display: none; }
259: #base64-table * { border: none; }
260: #base64-table tbody td:first-child:after { content: ':'; }
261: #base64-table tbody td:last-child { text-align: right; }
262:
1.1 mike 263: #named-character-references-table {
1.19 mike 264: white-space: nowrap;
1.1 mike 265: font-size: 0.6em;
1.19 mike 266: column-width: 30em;
1.1 mike 267: column-gap: 1em;
1.19 mike 268: -moz-column-width: 30em;
1.1 mike 269: -moz-column-gap: 1em;
1.19 mike 270: -webkit-column-width: 30em;
1.1 mike 271: -webkit-column-gap: 1em;
272: }
1.19 mike 273: #named-character-references-table > table > tbody > tr > td:first-child + td,
1.1 mike 274: #named-character-references-table > table > tbody > tr > td:last-child { text-align: center; }
275: #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; }
1.19 mike 276: #named-character-references-table > table > tbody > tr#entity-CounterClockwiseContourIntegral > td:first-child { font-size: 0.5em; }
1.1 mike 277:
1.2 mike 278: .glyph.control { color: red; }
279:
1.4 mike 280: @font-face {
281: font-family: 'Essays1743';
282: src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743.ttf');
283: }
284: @font-face {
285: font-family: 'Essays1743';
286: font-weight: bold;
287: src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743-Bold.ttf');
288: }
289: @font-face {
290: font-family: 'Essays1743';
291: font-style: italic;
292: src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743-Italic.ttf');
293: }
294: @font-face {
295: font-family: 'Essays1743';
296: font-style: italic;
297: font-weight: bold;
298: src: url('http://www.whatwg.org/specs/web-apps/current-work/fonts/Essays1743-BoldItalic.ttf');
299: }
300:
1.61 mike 301: </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">
1.45 mike 302: function getCookie(name) {
303: var params = location.search.substr(1).split("&");
304: for (var index = 0; index < params.length; index++) {
305: if (params[index] == name)
306: return "1";
307: var data = params[index].split("=");
308: if (data[0] == name)
309: return unescape(data[1]);
310: }
311: var cookies = document.cookie.split("; ");
312: for (var index = 0; index < cookies.length; index++) {
313: var data = cookies[index].split("=");
314: if (data[0] == name)
315: return unescape(data[1]);
316: }
317: return null;
318: }
1.241 mike 319: </script>
1.1 mike 320: <script src="link-fixup.js"></script>
1.146 mike 321: <link href="the-img-element.html" title="4.8.1 The img element" rel="prev">
322: <link href="index.html#contents" title="Table of contents" rel="contents">
323: <link href="the-embed-element.html" title="4.8.3 The embed element" rel="next">
1.167 mike 324: </head><body onload="fixBrokenLink();" class="split chapter"><div class="head" id="head">
1.1 mike 325: <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 326:
1.1 mike 327: <h1>HTML5</h1>
1.291 ! mike 328: <h2 class="no-num no-toc" id="a-vocabulary-and-associated-apis-for-html-and-xhtml">A vocabulary and associated APIs for HTML and XHTML</h2><p>This is revision 1.5682.</p>
1.230 mike 329:
1.290 mike 330: <h2 class="no-num no-toc" id="editor-s-draft-11-june-2012">Editor's Draft 11 June 2012</h2>
1.230 mike 331: </div>
1.146 mike 332:
1.230 mike 333: <nav class="prev_next">
1.146 mike 334: <a href="the-img-element.html">← 4.8.1 The img element</a> –
335: <a href="index.html#contents">Table of contents</a> –
336: <a href="the-embed-element.html">4.8.3 The embed element →</a>
337: </nav>
1.1 mike 338:
1.230 mike 339: <h4 id="the-iframe-element"><span class="secno">4.8.2 </span>The <dfn><code>iframe</code></dfn> element</h4>
340:
341: <dl class="element"><dt><a href="element-definitions.html#element-dfn-categories" title="element-dfn-categories">Categories</a>:</dt>
1.1 mike 342: <dd><a href="content-models.html#flow-content">Flow content</a>.</dd>
343: <dd><a href="content-models.html#phrasing-content">Phrasing content</a>.</dd>
344: <dd><a href="content-models.html#embedded-content">Embedded content</a>.</dd>
345: <dd><a href="content-models.html#interactive-content">Interactive content</a>.</dd>
1.126 mike 346: <dd><a href="content-models.html#palpable-content">Palpable content</a>.</dd>
1.170 mike 347: <dt><a href="element-definitions.html#element-dfn-contexts" title="element-dfn-contexts">Contexts in which this element can be used</a>:</dt>
1.1 mike 348: <dd>Where <a href="content-models.html#embedded-content">embedded content</a> is expected.</dd>
1.170 mike 349: <dt><a href="element-definitions.html#element-dfn-content-model" title="element-dfn-content-model">Content model</a>:</dt>
1.18 mike 350: <dd>Text that conforms to <a href="#iframe-content-model">the requirements given in the prose</a>.</dd>
1.170 mike 351: <dt><a href="element-definitions.html#element-dfn-attributes" title="element-dfn-attributes">Content attributes</a>:</dt>
1.146 mike 352: <dd><a href="global-attributes.html#global-attributes">Global attributes</a></dd>
1.1 mike 353: <dd><code title="attr-iframe-src"><a href="#attr-iframe-src">src</a></code></dd>
354: <dd><code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code></dd>
355: <dd><code title="attr-iframe-name"><a href="#attr-iframe-name">name</a></code></dd>
356: <dd><code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code></dd>
357: <dd><code title="attr-iframe-seamless"><a href="#attr-iframe-seamless">seamless</a></code></dd>
1.146 mike 358: <dd><code title="attr-dim-width"><a href="dimension-attributes.html#attr-dim-width">width</a></code></dd>
359: <dd><code title="attr-dim-height"><a href="dimension-attributes.html#attr-dim-height">height</a></code></dd>
1.170 mike 360: <dt><a href="element-definitions.html#element-dfn-dom" title="element-dfn-dom">DOM interface</a>:</dt>
1.1 mike 361: <dd>
362: <pre class="idl">interface <dfn id="htmliframeelement">HTMLIFrameElement</dfn> : <a href="elements.html#htmlelement">HTMLElement</a> {
363: attribute DOMString <a href="#dom-iframe-src" title="dom-iframe-src">src</a>;
364: attribute DOMString <a href="#dom-iframe-srcdoc" title="dom-iframe-srcdoc">srcdoc</a>;
365: attribute DOMString <a href="#dom-iframe-name" title="dom-iframe-name">name</a>;
1.81 mike 366: [PutForwards=<span title="dom-DOMSettableTokenList-value">value</span>] readonly attribute <a href="infrastructure.html#domsettabletokenlist">DOMSettableTokenList</a> <a href="#dom-iframe-sandbox" title="dom-iframe-sandbox">sandbox</a>;
1.1 mike 367: attribute boolean <a href="#dom-iframe-seamless" title="dom-iframe-seamless">seamless</a>;
1.146 mike 368: attribute DOMString <a href="dimension-attributes.html#dom-dim-width" title="dom-dim-width">width</a>;
369: attribute DOMString <a href="dimension-attributes.html#dom-dim-height" title="dom-dim-height">height</a>;
1.68 mike 370: readonly attribute Document? <a href="#dom-iframe-contentdocument" title="dom-iframe-contentDocument">contentDocument</a>;
371: readonly attribute <a href="browsers.html#windowproxy">WindowProxy</a>? <a href="#dom-iframe-contentwindow" title="dom-iframe-contentWindow">contentWindow</a>;
1.1 mike 372: };</pre>
373: </dd>
1.101 mike 374: </dl><p>The <code><a href="#the-iframe-element">iframe</a></code> element <a href="rendering.html#represents">represents</a> a
1.230 mike 375: <a href="browsers.html#nested-browsing-context">nested browsing context</a>.</p>
376:
377: <p>The <dfn id="attr-iframe-src" title="attr-iframe-src"><code>src</code></dfn> attribute
1.1 mike 378: gives the address of a page that the <a href="browsers.html#nested-browsing-context">nested browsing
379: context</a> is to contain. The attribute, if present, must be a
380: <a href="urls.html#valid-non-empty-url-potentially-surrounded-by-spaces">valid non-empty URL potentially surrounded by
1.230 mike 381: spaces</a>.</p>
382:
383:
384: <p>The <dfn id="attr-iframe-srcdoc" title="attr-iframe-srcdoc"><code>srcdoc</code></dfn>
1.1 mike 385: attribute gives the content of the page that the <a href="browsers.html#nested-browsing-context">nested
1.32 mike 386: browsing context</a> is to contain. The value of the attribute is
1.230 mike 387: the source of <dfn id="an-iframe-srcdoc-document">an <code>iframe</code> <code title="attr-iframe-srcdoc">srcdoc</code> document</dfn>.</p>
388:
389: <p>For <code><a href="#the-iframe-element">iframe</a></code> elements in <a href="infrastructure.html#html-documents">HTML documents</a>,
1.101 mike 390: the attribute, if present, must have a value using <a href="syntax.html#syntax">the HTML
1.1 mike 391: syntax</a> that consists of the following syntactic components,
1.230 mike 392: in the given order:</p>
393:
394: <ol><li>Any number of <a href="syntax.html#syntax-comments" title="syntax-comments">comments</a> and
1.1 mike 395: <a href="common-microsyntaxes.html#space-character" title="space character">space characters</a>.</li>
396:
1.101 mike 397: <li>Optionally, a <a href="syntax.html#syntax-doctype" title="syntax-doctype">DOCTYPE</a>.
1.1 mike 398:
1.101 mike 399: </li><li>Any number of <a href="syntax.html#syntax-comments" title="syntax-comments">comments</a> and
1.1 mike 400: <a href="common-microsyntaxes.html#space-character" title="space character">space characters</a>.</li>
401:
1.146 mike 402: <li>The root element, in the form of an <code><a href="the-html-element.html#the-html-element">html</a></code> <a href="syntax.html#syntax-elements" title="syntax-elements">element</a>.</li>
1.1 mike 403:
1.101 mike 404: <li>Any number of <a href="syntax.html#syntax-comments" title="syntax-comments">comments</a> and
1.1 mike 405: <a href="common-microsyntaxes.html#space-character" title="space character">space characters</a>.</li>
406:
1.82 mike 407: </ol><p>For <code><a href="#the-iframe-element">iframe</a></code> elements in <a href="infrastructure.html#xml-documents">XML documents</a>,
1.1 mike 408: the attribute, if present, must have a value that matches the
1.145 mike 409: production labeled <code><a href="dom.html#document">document</a></code> in the XML
1.230 mike 410: specification. <a href="references.html#refsXML">[XML]</a></p>
411:
412: <p>If the <code title="attr-iframe-src"><a href="#attr-iframe-src">src</a></code> attribute and the
1.1 mike 413: <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute are both
414: specified together, the <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code>
415: attribute takes priority. This allows authors to provide a fallback
416: <a href="urls.html#url">URL</a> for legacy user agents that do not support the
1.230 mike 417: <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute.</p>
418:
419: <div class="impl">
1.1 mike 420:
421: <p>When an <code><a href="#the-iframe-element">iframe</a></code> element is first <a href="infrastructure.html#insert-an-element-into-a-document" title="insert
422: an element into a document">inserted into a document</a>, the
423: user agent must create a <a href="browsers.html#nested-browsing-context">nested browsing context</a>, and
424: then <a href="#process-the-iframe-attributes">process the <code>iframe</code> attributes</a> for the
425: first time.</p>
426:
427: <p>Whenever an <code><a href="#the-iframe-element">iframe</a></code> element with a <a href="browsers.html#nested-browsing-context">nested
1.32 mike 428: browsing context</a> has its <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute set, changed, or
429: removed, the user agent must <a href="#process-the-iframe-attributes">process the <code>iframe</code>
1.1 mike 430: attributes</a>.</p>
431:
432: <p>Similarly, whenever an <code><a href="#the-iframe-element">iframe</a></code> element with a
433: <a href="browsers.html#nested-browsing-context">nested browsing context</a> but with no <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute specified has its
1.32 mike 434: <code title="attr-iframe-src"><a href="#attr-iframe-src">src</a></code> attribute set, changed, or
435: removed, the user agent must <a href="#process-the-iframe-attributes">process the <code>iframe</code>
1.46 mike 436: attributes</a>.</p>
1.149 mike 437:
1.1 mike 438: <p>When the user agent is to <dfn id="process-the-iframe-attributes">process the <code>iframe</code>
439: attributes</dfn>, it must run the first appropriate steps from the
440: following list:</p>
441:
442: <dl class="switch"><dt>If the <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute
443: is specified</dt>
444:
1.46 mike 445: <dd><p><a href="history.html#navigate">Navigate</a> the element's
1.34 mike 446: <a href="browsers.html#browsing-context">browsing context</a> to a resource whose
1.146 mike 447: <a href="urls.html#content-type">Content-Type</a> is <code><a href="iana.html#text-html">text/html</a></code>, whose
1.34 mike 448: <a href="urls.html#url">URL</a> is <code><a href="urls.html#about:srcdoc">about:srcdoc</a></code>, and whose data
449: consists of the value of the attribute. The resulting
1.145 mike 450: <code><a href="dom.html#document">Document</a></code> must be considered <a href="#an-iframe-srcdoc-document">an
1.34 mike 451: <code>iframe</code> <code title="attr-iframe-srcdoc">srcdoc</code>
452: document</a>.</p></dd>
1.1 mike 453:
454: <dt>If the <code title="attr-iframe-src"><a href="#attr-iframe-src">src</a></code>
455: attribute is specified but the <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute is not</dt>
456:
457: <dd>
458:
459: <ol><li><p>If the value of the <code title="attr-iframe-src"><a href="#attr-iframe-src">src</a></code> attribute is the empty string,
460: jump to the <i title="">empty</i> step below.</p></li>
461:
462: <li><p><a href="urls.html#resolve-a-url" title="resolve a url">Resolve</a> the value of
463: the <code title="attr-iframe-src"><a href="#attr-iframe-src">src</a></code> attribute, relative
464: to the <code><a href="#the-iframe-element">iframe</a></code> element.</p></li>
465:
466: <li><p>If that is not successful, then jump to the <i title="">empty</i> step below.</p></li>
467:
468: <li><p>If the resulting <a href="urls.html#absolute-url">absolute URL</a> is an
469: <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a> match for the string
1.146 mike 470: "<code><a href="urls.html#about:blank">about:blank</a></code>", and the user agent is processing this
1.1 mike 471: <code><a href="#the-iframe-element">iframe</a></code>'s attributes for the first time, then jump to
472: the <i title="">empty</i> step below. (In cases other than the
1.146 mike 473: first time, <code><a href="urls.html#about:blank">about:blank</a></code> is loaded
1.1 mike 474: normally.)</p></li>
475:
1.46 mike 476: <li><p><a href="history.html#navigate">Navigate</a> the element's
1.34 mike 477: <a href="browsers.html#browsing-context">browsing context</a> to the resulting <a href="urls.html#absolute-url">absolute
1.1 mike 478: URL</a>.</p></li>
479:
480: </ol><p><i>Empty</i>: When the steps above require the user agent to
481: jump to the <i title="">empty</i> step, if the user agent is
482: processing this <code><a href="#the-iframe-element">iframe</a></code>'s attributes for the first
483: time, then the user agent must <a href="webappapis.html#queue-a-task">queue a task</a> to
1.66 mike 484: <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-iframe-element">iframe</a></code> element.
485: (After jumping to this step, the above steps are not resumed.)
486: <span class="note">No <code title="event-load">load</code> event
1.146 mike 487: is fired at the <code><a href="urls.html#about:blank">about:blank</a></code> document
1.66 mike 488: itself.</span></p>
1.1 mike 489:
490: </dd>
491:
492: <dt>Otherwise</dt>
493:
494: <dd>
495:
496: <p><a href="webappapis.html#queue-a-task">Queue a task</a> to <a href="webappapis.html#fire-a-simple-event">fire a simple event</a>
497: named <code title="event-load">load</code> at the
498: <code><a href="#the-iframe-element">iframe</a></code> element.</p>
499:
500: </dd>
501:
502: </dl><p>Any <a href="history.html#navigate" title="navigate">navigation</a> required of the user
503: agent in the <a href="#process-the-iframe-attributes">process the <code>iframe</code> attributes</a>
504: algorithm must be completed with the <code><a href="#the-iframe-element">iframe</a></code> element's
505: document's <a href="browsers.html#browsing-context">browsing context</a> as the <a href="history.html#source-browsing-context">source
506: browsing context</a>.</p>
507:
1.8 mike 508: <p>Furthermore, if the <a href="browsers.html#browsing-context">browsing context</a>'s <a href="history.html#session-history">session
1.145 mike 509: history</a> contained only one <code><a href="dom.html#document">Document</a></code> when the
1.8 mike 510: <a href="#process-the-iframe-attributes">process the <code>iframe</code> attributes</a> algorithm
1.146 mike 511: was invoked, and that was the <code><a href="urls.html#about:blank">about:blank</a></code>
1.145 mike 512: <code><a href="dom.html#document">Document</a></code> created when the <a href="browsers.html#browsing-context">browsing context</a>
1.8 mike 513: was created, then any <a href="history.html#navigate" title="navigate">navigation</a>
514: required of the user agent in that algorithm must be completed with
1.46 mike 515: <a href="history.html#replacement-enabled">replacement enabled</a>.</p>
1.149 mike 516:
1.230 mike 517: </div>
518:
519: <p class="note">If, when the element is created, the <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute is not set, and
1.1 mike 520: the <code title="attr-iframe-src"><a href="#attr-iframe-src">src</a></code> attribute is either
521: also not set or set but its value cannot be <a href="urls.html#resolve-a-url" title="resolve a
522: url">resolved</a>, the browsing context will remain at the
1.230 mike 523: initial <code><a href="urls.html#about:blank">about:blank</a></code> page.</p>
524:
525: <p class="note">If the user <a href="history.html#navigate" title="navigate">navigates</a>
1.1 mike 526: away from this page, the <code><a href="#the-iframe-element">iframe</a></code>'s corresponding
527: <code><a href="browsers.html#windowproxy">WindowProxy</a></code> object will proxy new <code><a href="browsers.html#window">Window</a></code>
1.230 mike 528: objects for new <code><a href="dom.html#document">Document</a></code> objects, but the <code title="attr-iframe-src"><a href="#attr-iframe-src">src</a></code> attribute will not change.</p>
529:
530: <div class="impl">
1.9 mike 531:
532: <div class="note">
533:
534: <p><a href="infrastructure.html#remove-an-element-from-a-document" title="remove an element from a document">Removing</a>
1.145 mike 535: an <code><a href="#the-iframe-element">iframe</a></code> from a <code><a href="dom.html#document">Document</a></code> does not cause
1.9 mike 536: its <a href="browsers.html#browsing-context">browsing context</a> to be discarded. Indeed, an
537: <code><a href="#the-iframe-element">iframe</a></code>'s <a href="browsers.html#browsing-context">browsing context</a> can survive its
1.145 mike 538: original parent <code><a href="dom.html#document">Document</a></code> if its <code><a href="#the-iframe-element">iframe</a></code> is
539: moved to another <code><a href="dom.html#document">Document</a></code>.</p>
1.9 mike 540:
1.10 mike 541: <p>On the other hand, if an <code><a href="#the-iframe-element">iframe</a></code> is <a href="infrastructure.html#remove-an-element-from-a-document" title="remove an element from a document">removed</a> from a
1.145 mike 542: <code><a href="dom.html#document">Document</a></code> and is then subsequently garbage collected,
1.10 mike 543: this will likely mean (in the absence of other references) that the
544: <a href="browsers.html#child-browsing-context">child browsing context</a>'s <code><a href="browsers.html#windowproxy">WindowProxy</a></code>
545: object will become eligble for garbage collection, which will then
546: lead to that <a href="browsers.html#browsing-context">browsing context</a> being <a href="browsers.html#a-browsing-context-is-discarded" title="a
547: browsing context is discarded">discarded</a>, which will then
1.145 mike 548: lead to its <code><a href="dom.html#document">Document</a></code> being <a href="browsers.html#discard-a-document" title="discard a
1.9 mike 549: document">discarded</a> also. This happens without notice to any
1.145 mike 550: scripts running in that <code><a href="dom.html#document">Document</a></code>; for example, no
1.9 mike 551: <code title="event-unload">unload</code> events are fired (the
1.10 mike 552: "<a href="history.html#unload-a-document">unload a document</a>" steps are not run).</p>
1.9 mike 553:
554: </div>
555:
1.230 mike 556: </div>
557:
558: <div class="example">
1.1 mike 559:
560: <p>Here a blog uses the <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute in conjunction
561: with the <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code> and <code title="attr-iframe-seamless"><a href="#attr-iframe-seamless">seamless</a></code> attributes described
562: below to provide users of user agents that support this feature
563: with an extra layer of protection from script injection in the blog
564: post comments:</p>
565:
566: <pre><article>
567: <h1>I got my own magazine!</h1>
568: <p>After much effort, I've finally found a publisher, and so now I
569: have my own magazine! Isn't that awesome?! The first issue will come
570: out in September, and we have articles about getting food, and about
571: getting in boxes, it's going to be great!</p>
572: <footer>
1.145 mike 573: <p>Written by <a href="/users/cap">cap</a>, 1 hour ago.
1.1 mike 574: </footer>
575: <article>
1.145 mike 576: <footer> Thirteen minutes ago, <a href="/users/ch">ch</a> wrote: </footer>
1.33 mike 577: <iframe seamless sandbox srcdoc="<p>did you get a cover picture yet?"></iframe>
1.1 mike 578: </article>
579: <article>
1.145 mike 580: <footer> Nine minutes ago, <a href="/users/cap">cap</a> wrote: </footer>
1.33 mike 581: <iframe seamless sandbox srcdoc="<p>Yeah, you can see it <a href=&quot;/gallery?mode=cover&amp;amp;page=1&quot;>in my gallery</a>."></iframe>
1.1 mike 582: </article>
583: <article>
1.145 mike 584: <footer> Five minutes ago, <a href="/users/ch">ch</a> wrote: </footer>
1.33 mike 585: <iframe seamless sandbox srcdoc="<p>hey that's earl's table.
1.1 mike 586: <p>you should get earl&amp;amp;me on the next cover."></iframe>
587: </article></pre>
588:
589: <p>Notice the way that quotes have to be escaped (otherwise the
1.101 mike 590: <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute would end
591: prematurely), and the way raw ampersands (e.g. in URLs or in prose)
592: mentioned in the sandboxed content have to be <em>doubly</em>
593: escaped — once so that the ampersand is preserved when
594: originally parsing the <code title="attr-iframe-srcdoc"><a href="#attr-iframe-srcdoc">srcdoc</a></code> attribute, and once more
1.1 mike 595: to prevent the ampersand from being misinterpreted when parsing the
596: sandboxed content.</p>
597:
1.230 mike 598: </div>
599:
600: <p class="note">In <a href="syntax.html#syntax">the HTML syntax</a>, authors need only
601: remember to use """ (U+0022) characters to wrap the
602: attribute contents and then to escape all """ (U+0022)
1.1 mike 603: and U+0026 AMPERSAND (&) characters, and to specify the <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code> attribute, to ensure safe
1.230 mike 604: embedding of content.</p>
605:
606: <p class="note">Due to restrictions of <a href="the-xhtml-syntax.html#the-xhtml-syntax">the XHTML
1.141 mike 607: syntax</a>, in XML the U+003C LESS-THAN SIGN character (<)
608: needs to be escaped as well. In order to prevent <a href="http://www.w3.org/TR/REC-xml/#AVNormalize">attribute-value
1.39 mike 609: normalization</a>, some of XML's whitespace characters —
1.230 mike 610: specifically "tab" (U+0009), "LF" (U+000A), and "CR" (U+000D) — also need to be
611: escaped. <a href="references.html#refsXML">[XML]</a></p>
612:
613: <hr><p>The <dfn id="attr-iframe-name" title="attr-iframe-name"><code>name</code></dfn>
1.1 mike 614: attribute, if present, must be a <a href="browsers.html#valid-browsing-context-name">valid browsing context
615: name</a>. The given value is used to name the <a href="browsers.html#nested-browsing-context">nested
616: browsing context</a>. <span class="impl">When the browsing
617: context is created, if the attribute is present, the <a href="browsers.html#browsing-context-name">browsing
618: context name</a> must be set to the value of this attribute;
619: otherwise, the <a href="browsers.html#browsing-context-name">browsing context name</a> must be set to the
1.230 mike 620: empty string.</span></p>
621:
622: <div class="impl">
1.1 mike 623:
624: <p>Whenever the <code title="attr-iframe-name"><a href="#attr-iframe-name">name</a></code> attribute
625: is set, the nested <a href="browsers.html#browsing-context">browsing context</a>'s <a href="browsers.html#browsing-context-name" title="browsing context name">name</a> must be changed to the new
626: value. If the attribute is removed, the <a href="browsers.html#browsing-context-name">browsing context
627: name</a> must be set to the empty string.</p>
628:
629: <p>When content loads in an <code><a href="#the-iframe-element">iframe</a></code>, after any <code title="event-load">load</code> events are fired within the content
630: itself, the user agent must <a href="webappapis.html#queue-a-task">queue a task</a> to <a href="webappapis.html#fire-a-simple-event">fire
631: a simple event</a> named <code title="event-load">load</code> at
632: the <code><a href="#the-iframe-element">iframe</a></code> element. When content whose <a href="urls.html#url">URL</a>
633: has the <a href="origin-0.html#same-origin">same origin</a> as the <code><a href="#the-iframe-element">iframe</a></code>
1.145 mike 634: element's <code><a href="dom.html#document">Document</a></code> fails to load (e.g. due to a DNS
1.1 mike 635: error, network error, or if the server returned a 4xx or 5xx status
1.146 mike 636: code <a href="urls.html#concept-http-equivalent-codes" title="concept-http-equivalent-codes">or
1.1 mike 637: equivalent</a>), then the user agent must <a href="webappapis.html#queue-a-task">queue a
638: task</a> to <a href="webappapis.html#fire-a-simple-event">fire a simple event</a> named <code title="event-error">error</code> at the element instead. (This event
1.101 mike 639: does not fire for <a href="parsing.html#parse-error" title="parse error">parse errors</a>,
1.1 mike 640: script errors, or any errors for cross-origin resources.)</p>
641:
642: <p>The <a href="webappapis.html#task-source">task source</a> for these <a href="webappapis.html#concept-task" title="concept-task">tasks</a> is the <a href="webappapis.html#dom-manipulation-task-source">DOM manipulation
643: task source</a>.</p>
644:
645: <p class="note">A <code title="event-load">load</code> event is also
646: fired at the <code><a href="#the-iframe-element">iframe</a></code> element when it is created if no
647: other data is loaded in it.</p>
648:
649: <p>When there is an <a href="dom.html#active-parser">active parser</a> in the
650: <code><a href="#the-iframe-element">iframe</a></code>, and when anything in the <code><a href="#the-iframe-element">iframe</a></code> is
1.101 mike 651: <a href="the-end.html#delay-the-load-event" title="delay the load event">delaying the load event</a> of
1.1 mike 652: the <code><a href="#the-iframe-element">iframe</a></code>'s <a href="browsers.html#browsing-context">browsing context</a>'s
653: <a href="browsers.html#active-document">active document</a>, the <code><a href="#the-iframe-element">iframe</a></code> must
1.101 mike 654: <a href="the-end.html#delay-the-load-event">delay the load event</a> of its document.</p>
1.1 mike 655:
656: <p class="note">If, during the handling of the <code title="event-load">load</code> event, the <a href="browsers.html#browsing-context">browsing
1.101 mike 657: context</a> in the <code><a href="#the-iframe-element">iframe</a></code> is again <a href="history.html#navigate" title="navigate">navigated</a>, that will further <a href="the-end.html#delay-the-load-event">delay the
1.1 mike 658: load event</a>.</p>
659:
1.230 mike 660: </div>
661:
662: <hr><p>The <dfn id="attr-iframe-sandbox" title="attr-iframe-sandbox"><code>sandbox</code></dfn>
1.1 mike 663: attribute, when specified, enables a set of extra restrictions on
664: any content hosted by the <code><a href="#the-iframe-element">iframe</a></code>. Its value must be an
1.20 mike 665: <a href="common-microsyntaxes.html#unordered-set-of-unique-space-separated-tokens">unordered set of unique space-separated tokens</a> that are
1.77 mike 666: <a href="infrastructure.html#ascii-case-insensitive">ASCII case-insensitive</a>. The allowed values are
1.253 mike 667: <code title="attr-iframe-sandbox-allow-forms"><a href="origin-0.html#attr-iframe-sandbox-allow-forms">allow-forms</a></code>,
1.254 mike 668: <code title="attr-iframe-sandbox-allow-popups"><a href="origin-0.html#attr-iframe-sandbox-allow-popups">allow-popups</a></code>,
1.253 mike 669: <code title="attr-iframe-sandbox-allow-same-origin"><a href="origin-0.html#attr-iframe-sandbox-allow-same-origin">allow-same-origin</a></code>,
670: <code title="attr-iframe-sandbox-allow-scripts"><a href="origin-0.html#attr-iframe-sandbox-allow-scripts">allow-scripts</a></code>, and
671: <code title="attr-iframe-sandbox-allow-top-navigation"><a href="origin-0.html#attr-iframe-sandbox-allow-top-navigation">allow-top-navigation</a></code>.
1.77 mike 672:
673: When the attribute is set, the content is treated as being from a
674: unique <a href="origin-0.html#origin">origin</a>, forms and scripts are disabled, links
675: are prevented from targeting other <a href="browsers.html#browsing-context" title="browsing
1.114 mike 676: context">browsing contexts</a>, and plugins are secured. The
1.253 mike 677: <code title="attr-iframe-sandbox-allow-same-origin"><a href="origin-0.html#attr-iframe-sandbox-allow-same-origin">allow-same-origin</a></code>
1.1 mike 678: keyword allows the content to be treated as being from the same
1.253 mike 679: origin instead of forcing it into a unique origin, the <code title="attr-iframe-sandbox-allow-top-navigation"><a href="origin-0.html#attr-iframe-sandbox-allow-top-navigation">allow-top-navigation</a></code>
1.1 mike 680: keyword allows the content to <a href="history.html#navigate">navigate</a> its
1.254 mike 681: <a href="browsers.html#top-level-browsing-context">top-level browsing context</a>, and the <code title="attr-iframe-sandbox-allow-forms"><a href="origin-0.html#attr-iframe-sandbox-allow-forms">allow-forms</a></code>, <code title="attr-iframe-sandbox-allow-popups"><a href="origin-0.html#attr-iframe-sandbox-allow-popups">allow-popups</a></code> and <code title="attr-iframe-sandbox-allow-scripts"><a href="origin-0.html#attr-iframe-sandbox-allow-scripts">allow-scripts</a></code>
682: keywords re-enable forms, popups, and scripts respectively.</p>
1.230 mike 683:
684: <p class="warning">Setting both the
1.253 mike 685: <code title="attr-iframe-sandbox-allow-scripts"><a href="origin-0.html#attr-iframe-sandbox-allow-scripts">allow-scripts</a></code> and
686: <code title="attr-iframe-sandbox-allow-same-origin"><a href="origin-0.html#attr-iframe-sandbox-allow-same-origin">allow-same-origin</a></code>
1.1 mike 687: keywords together when the embedded page has the <a href="origin-0.html#same-origin">same
688: origin</a> as the page containing the <code><a href="#the-iframe-element">iframe</a></code> allows
1.230 mike 689: the embedded page to simply remove the <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code> attribute.</p>
690:
691: <p class="warning">Sandboxing hostile content is of minimal help if
1.1 mike 692: an attacker can convince the user to just visit the hostile content
693: directly, rather than in the <code><a href="#the-iframe-element">iframe</a></code>. To limit the
694: damage that can be caused by hostile HTML content, it should be
1.230 mike 695: served from a separate dedicated domain.</p>
696:
697: <div class="impl">
1.1 mike 698:
1.46 mike 699:
1.149 mike 700:
1.1 mike 701: <p>While the <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code>
1.253 mike 702: attribute is set or changed, the user agent must <a href="origin-0.html#parse-a-sandboxing-directive" title="parse
703: a sandboxing directive">parse the sandboxing directive</a> using
704: the attribute's value as the <var title="">input</var> and the
705: <code><a href="#the-iframe-element">iframe</a></code> element's <a href="browsers.html#nested-browsing-context">nested browsing context</a>'s
706: <a href="origin-0.html#iframe-sandboxing-flag-set"><code>iframe</code> sandboxing flag set</a> as the
707: output.</p>
1.1 mike 708:
709: <p class="warning">These flags only take effect when the
710: <a href="browsers.html#nested-browsing-context">nested browsing context</a> of the <code><a href="#the-iframe-element">iframe</a></code> is
1.15 mike 711: <a href="history.html#navigate" title="navigate">navigated</a>. Removing them, or removing
1.1 mike 712: the entire <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code>
713: attribute, has no effect on an already-loaded page.</p>
714:
1.230 mike 715: </div>
716:
717: <div class="example">
1.1 mike 718:
719: <p>In this example, some completely-unknown, potentially hostile,
720: user-provided HTML content is embedded in a page. Because it is
1.127 mike 721: served from a separate domain, it is affected by all the normal
722: cross-site restrictions. In addition, the embedded page has
723: scripting disabled, plugins disabled, forms disabled, and it cannot
724: navigate any frames or windows other than itself (or any frames or
725: windows it itself embeds).</p>
1.1 mike 726:
727: <pre><p>We're not scared of you! Here is your content, unedited:</p>
1.127 mike 728: <iframe sandbox src="http://usercontent.example.net/getusercontent.cgi?id=12193"></iframe></pre>
1.1 mike 729:
1.127 mike 730: <p class="warning">It is important to use a separate domain so that
731: if the attacker convinces the user to visit that page directly, the
732: page doesn't run in the context of the site's origin, which would
733: make the user vulnerable to any attack found in the page.</p>
1.1 mike 734:
1.230 mike 735: </div>
736:
737: <div class="example">
1.1 mike 738:
739: <p>In this example, a gadget from another site is embedded. The
740: gadget has scripting and forms enabled, and the origin sandbox
741: restrictions are lifted, allowing the gadget to communicate with
742: its originating server. The sandbox is still useful, however, as it
743: disables plugins and popups, thus reducing the risk of the user
744: being exposed to malware and other annoyances.</p>
745:
746: <pre><iframe sandbox="allow-same-origin allow-forms allow-scripts"
747: src="http://maps.example.com/embedded.html"></iframe></pre>
748:
1.230 mike 749: </div>
750:
751: <div class="example">
1.1 mike 752:
753: <p>Suppose a file A contained the following fragment:</p>
754:
755: <pre><iframe sandbox="allow-same-origin allow-forms" src=B></iframe></pre>
756:
757: <p>Suppose that file B contained an iframe also:</p>
758:
759: <pre><iframe sandbox="allow-scripts" src=C></iframe></pre>
760:
761: <p>Further, suppose that file C contained a link:</p>
762:
763: <pre><a href=D>Link</a></pre>
764:
765: <p>For this example, suppose all the files were served as
1.101 mike 766: <code><a href="iana.html#text-html">text/html</a></code>.</p>
1.1 mike 767:
768: <p>Page C in this scenario has all the sandboxing flags
769: set. Scripts are disabled, because the <code><a href="#the-iframe-element">iframe</a></code> in A has
1.253 mike 770: scripts disabled, and this overrides the <code title="attr-iframe-sandbox-allow-scripts"><a href="origin-0.html#attr-iframe-sandbox-allow-scripts">allow-scripts</a></code>
1.1 mike 771: keyword set on the <code><a href="#the-iframe-element">iframe</a></code> in B. Forms are also
772: disabled, because the inner <code><a href="#the-iframe-element">iframe</a></code> (in B) does not
1.253 mike 773: have the <code title="attr-iframe-sandbox-allow-forms"><a href="origin-0.html#attr-iframe-sandbox-allow-forms">allow-forms</a></code> keyword
1.1 mike 774: set.</p>
775:
1.142 mike 776: <p>Suppose now that a script in A removes all the <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code> attributes in A
777: and B. This would change nothing
778: immediately. If the user clicked the link in C, loading page D into
779: the <code><a href="#the-iframe-element">iframe</a></code> in B, page D would now act as if the
1.253 mike 780: <code><a href="#the-iframe-element">iframe</a></code> in B had the <code title="attr-iframe-sandbox-allow-same-origin"><a href="origin-0.html#attr-iframe-sandbox-allow-same-origin">allow-same-origin</a></code>
781: and <code title="attr-iframe-sandbox-allow-forms"><a href="origin-0.html#attr-iframe-sandbox-allow-forms">allow-forms</a></code> keywords
1.1 mike 782: set, because that was the state of the <a href="browsers.html#nested-browsing-context">nested browsing
783: context</a> in the <code><a href="#the-iframe-element">iframe</a></code> in A when page B was
784: loaded.</p>
785:
786: <p>Generally speaking, dynamically removing or changing the <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code> attribute is
787: ill-advised, because it can make it quite hard to reason about what
788: will be allowed and what will not.</p>
789:
1.230 mike 790: </div>
791:
792: <p class="note">Potentially hostile files should not be served from
1.127 mike 793: the same server as the file containing the <code><a href="#the-iframe-element">iframe</a></code>
794: element. Using a different domain ensures that scripts in the files
795: are unable to attack the site, even if the user is tricked into
1.230 mike 796: visiting those pages directly, without the protection of the <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code> attribute.</p>
797:
1.253 mike 798: <p class="warning">If the <code title="attr-iframe-sandbox-allow-scripts"><a href="origin-0.html#attr-iframe-sandbox-allow-scripts">allow-scripts</a></code>
799: keyword is set along with <code title="attr-iframe-sandbox-allow-same-origin"><a href="origin-0.html#attr-iframe-sandbox-allow-same-origin">allow-same-origin</a></code>
1.1 mike 800: keyword, and the file is from the <a href="origin-0.html#same-origin">same origin</a> as the
1.145 mike 801: <code><a href="#the-iframe-element">iframe</a></code>'s <code><a href="dom.html#document">Document</a></code>, then a script in the
1.1 mike 802: "sandboxed" iframe could just reach out, remove the <code title="attr-iframe-sandbox"><a href="#attr-iframe-sandbox">sandbox</a></code> attribute, and then
803: reload itself, effectively breaking out of the sandbox
1.230 mike 804: altogether.</p>
805:
806:
807: <hr><p>The <dfn id="attr-iframe-seamless" title="attr-iframe-seamless"><code>seamless</code></dfn>
1.1 mike 808: attribute is a <a href="common-microsyntaxes.html#boolean-attribute">boolean attribute</a>. When specified, it
809: indicates that the <code><a href="#the-iframe-element">iframe</a></code> element's <a href="browsers.html#browsing-context">browsing
810: context</a> is to be rendered in a manner that makes it appear to
811: be part of the containing document (seamlessly included in the
812: parent document). <span class="impl">Specifically, when the
813: attribute is set on an <code><a href="#the-iframe-element">iframe</a></code> element whose owner
1.253 mike 814: <code><a href="dom.html#document">Document</a></code>'s <a href="origin-0.html#active-sandboxing-flag-set">active sandboxing flag set</a> does
815: not have the <a href="origin-0.html#sandboxed-seamless-iframes-flag">sandboxed seamless iframes flag</a> set, and
816: while either the <a href="browsers.html#browsing-context">browsing context</a>'s <a href="browsers.html#active-document">active
817: document</a> has the <a href="origin-0.html#same-origin">same origin</a> as the
1.33 mike 818: <code><a href="#the-iframe-element">iframe</a></code> element's document, or the <a href="browsers.html#browsing-context">browsing
1.253 mike 819: context</a>'s <a href="browsers.html#active-document">active document</a>'s <em><a href="dom.html#the-document-s-address" title="the
820: document's address">address</a></em> has the <a href="origin-0.html#same-origin">same
821: origin</a> as the <code><a href="#the-iframe-element">iframe</a></code> element's document, or the
822: <a href="browsers.html#browsing-context">browsing context</a>'s <a href="browsers.html#active-document">active document</a> is
823: <a href="#an-iframe-srcdoc-document">an <code>iframe</code> <code title="attr-iframe-srcdoc">srcdoc</code> document</a>, the
824: following requirements apply:</span></p>
1.230 mike 825:
826: <div class="impl">
1.1 mike 827:
1.13 mike 828: <ul><li><p>The user agent must set the <dfn id="seamless-browsing-context-flag">seamless browsing context
829: flag</dfn> to true for that <a href="browsers.html#browsing-context">browsing context</a>. This
830: will <a href="history.html#seamlessLinks">cause links to open in the parent
831: browsing context</a> unless an <a href="browsers.html#explicit-self-navigation-override">explicit self-navigation
832: override</a> is used (<code title="">target="_self"</code>).</p></li>
1.1 mike 833:
834: <li><p>In a CSS-supporting user agent: the user agent must add all
835: the style sheets that apply to the <code><a href="#the-iframe-element">iframe</a></code> element to
836: the cascade of the <a href="browsers.html#active-document">active document</a> of the
837: <code><a href="#the-iframe-element">iframe</a></code> element's <a href="browsers.html#nested-browsing-context">nested browsing context</a>,
838: at the appropriate cascade levels, before any style sheets
839: specified by the document itself.</p></li>
840:
841: <li><p>In a CSS-supporting user agent: the user agent must, for the
842: purpose of CSS property inheritance only, treat the root element of
843: the <a href="browsers.html#active-document">active document</a> of the <code><a href="#the-iframe-element">iframe</a></code>
844: element's <a href="browsers.html#nested-browsing-context">nested browsing context</a> as being a child of
845: the <code><a href="#the-iframe-element">iframe</a></code> element. (Thus inherited properties on the
846: root element of the document in the <code><a href="#the-iframe-element">iframe</a></code> will
847: inherit the computed values of those properties on the
848: <code><a href="#the-iframe-element">iframe</a></code> element instead of taking their initial
849: values.)</p></li>
850:
851: <li><p>In visual media, in a CSS-supporting user agent: the user agent
852: should set the intrinsic width of the <code><a href="#the-iframe-element">iframe</a></code> to the
853: width that the element would have if it was a non-replaced
854: block-level element with 'width: auto'.</p></li>
855:
856: <li><p>In visual media, in a CSS-supporting user agent: the user
857: agent should set the intrinsic height of the <code><a href="#the-iframe-element">iframe</a></code> to
858: the height of the bounding box around the content rendered in the
859: <code><a href="#the-iframe-element">iframe</a></code> at its current width (as given in the previous
860: bullet point), as it would be if the scrolling position was such
861: that the top of the viewport for the content rendered in the
862: <code><a href="#the-iframe-element">iframe</a></code> was aligned with the origin of that content's
863: canvas.</p></li>
864:
865: <li>
866:
867: <p>In visual media, in a CSS-supporting user agent: the user agent
868: must force the height of the initial containing block of the
869: <a href="browsers.html#active-document">active document</a> of the <a href="browsers.html#nested-browsing-context">nested browsing
870: context</a> of the <code><a href="#the-iframe-element">iframe</a></code> to zero.</p>
871:
872: <p class="note">This is intended to get around the otherwise
873: circular dependency of percentage dimensions that depend on the
874: height of the containing block, thus affecting the height of the
875: document's bounding box, thus affecting the height of the
876: viewport, thus affecting the size of the initial containing
877: block.</p>
878:
879: </li>
880:
881: <li><p>In speech media, the user agent should render the <a href="browsers.html#nested-browsing-context">nested
882: browsing context</a> without announcing that it is a separate
883: document.</p></li>
884:
885: <li>
886:
887: <p>User agents should, in general, act as if the <a href="browsers.html#active-document">active
888: document</a> of the <code><a href="#the-iframe-element">iframe</a></code>'s <a href="browsers.html#nested-browsing-context">nested browsing
889: context</a> was part of the document that the
1.35 mike 890: <code><a href="#the-iframe-element">iframe</a></code> is in, if any.</p>
1.1 mike 891:
892: <p class="example">For example if the user agent supports listing
893: all the links in a document, links in "seamlessly" nested
894: documents would be included in that list without being
895: significantly distinguished from links in the document itself.</p>
896:
897: </li>
898:
899: </ul><p>If the attribute is not specified, or if the <a href="origin-0.html#origin">origin</a>
900: conditions listed above are not met, then the user agent should
901: render the <a href="browsers.html#nested-browsing-context">nested browsing context</a> in a manner that is
902: clearly distinguishable as a separate <a href="browsers.html#browsing-context">browsing context</a>,
903: and the <a href="#seamless-browsing-context-flag">seamless browsing context flag</a> must be set to
904: false for that <a href="browsers.html#browsing-context">browsing context</a>.</p>
905:
906: <p class="warning">It is important that user agents recheck the
907: above conditions whenever the <a href="browsers.html#active-document">active document</a> of the
908: <a href="browsers.html#nested-browsing-context">nested browsing context</a> of the <code><a href="#the-iframe-element">iframe</a></code>
909: changes, such that the <a href="#seamless-browsing-context-flag">seamless browsing context flag</a>
910: gets unset if the <a href="browsers.html#nested-browsing-context">nested browsing context</a> is <a href="history.html#navigate" title="navigate">navigated</a> to another origin.</p>
911:
1.230 mike 912: </div>
913:
914: <p class="note">The attribute can be set or removed dynamically,
915: with the rendering updating in tandem.</p>
916:
917: <div class="example">
1.1 mike 918:
919: <p>In this example, the site's navigation is embedded using a
920: client-side include using an <code><a href="#the-iframe-element">iframe</a></code>. Any links in the
921: <code><a href="#the-iframe-element">iframe</a></code> will, in new user agents, be automatically
922: opened in the <code><a href="#the-iframe-element">iframe</a></code>'s parent browsing context; for
1.146 mike 923: legacy user agents, the site could also include a <code><a href="the-base-element.html#the-base-element">base</a></code>
924: element with a <code title="attr-base-target"><a href="the-base-element.html#attr-base-target">target</a></code>
1.1 mike 925: attribute with the value <code title="">_parent</code>. Similarly,
926: in new user agents the styles of the parent page will be
927: automatically applied to the contents of the frame, but to support
928: legacy user agents authors might wish to include the styles
929: explicitly.</p>
930:
931: <pre><nav><iframe seamless src="nav.include.html"></iframe></nav></pre>
932:
1.230 mike 933: </div>
934:
935:
936: <hr><p>The <code><a href="#the-iframe-element">iframe</a></code> element supports <a href="dimension-attributes.html#dimension-attributes">dimension
1.1 mike 937: attributes</a> for cases where the embedded content has specific
1.230 mike 938: dimensions (e.g. ad units have well-defined dimensions).</p>
939:
940: <p>An <code><a href="#the-iframe-element">iframe</a></code> element never has <a href="content-models.html#fallback-content">fallback
1.1 mike 941: content</a>, as it will always create a nested <a href="browsers.html#browsing-context">browsing
942: context</a>, regardless of whether the specified initial contents
1.230 mike 943: are successfully used.</p>
944:
945: <p>Descendants of <code><a href="#the-iframe-element">iframe</a></code> elements represent
1.1 mike 946: nothing. (In legacy user agents that do not support
947: <code><a href="#the-iframe-element">iframe</a></code> elements, the contents would be parsed as markup
1.230 mike 948: that could act as fallback content.)</p>
949:
950: <p id="iframe-content-model">When used in <a href="infrastructure.html#html-documents">HTML
1.18 mike 951: documents</a>, the allowed content model of <code><a href="#the-iframe-element">iframe</a></code>
1.101 mike 952: elements is text, except that invoking the <a href="the-end.html#html-fragment-parsing-algorithm">HTML fragment
1.18 mike 953: parsing algorithm</a> with the <code><a href="#the-iframe-element">iframe</a></code> element as the
1.101 mike 954: <var title="concept-frag-parse-context"><a href="the-end.html#concept-frag-parse-context">context</a></var> element and
1.48 mike 955: the text contents as the <var title="">input</var> must result in a
956: list of nodes that are all <a href="content-models.html#phrasing-content">phrasing content</a>, with no
1.101 mike 957: <a href="parsing.html#parse-error" title="parse error">parse errors</a> having occurred, with
1.146 mike 958: no <code><a href="the-script-element.html#the-script-element">script</a></code> elements being anywhere in the list or as
1.18 mike 959: descendants of elements in the list, and with all the elements in
960: the list (including their descendants) being themselves
1.230 mike 961: conforming.</p>
962:
963: <p>The <code><a href="#the-iframe-element">iframe</a></code> element must be empty in <a href="infrastructure.html#xml-documents">XML
964: documents</a>.</p>
965:
966: <p class="note">The <a href="parsing.html#html-parser">HTML parser</a> treats markup inside
967: <code><a href="#the-iframe-element">iframe</a></code> elements as text.</p>
968:
969: <div class="impl">
1.1 mike 970:
971: <p>The IDL attributes <dfn id="dom-iframe-src" title="dom-iframe-src"><code>src</code></dfn>, <dfn id="dom-iframe-srcdoc" title="dom-iframe-srcdoc"><code>srcdoc</code></dfn>, <dfn id="dom-iframe-name" title="dom-iframe-name"><code>name</code></dfn>, <dfn id="dom-iframe-sandbox" title="dom-iframe-sandbox"><code>sandbox</code></dfn>, and <dfn id="dom-iframe-seamless" title="dom-iframe-seamless"><code>seamless</code></dfn> must
972: <a href="common-dom-interfaces.html#reflect">reflect</a> the respective content attributes of the same
973: name.</p>
974:
975: <p>The <dfn id="dom-iframe-contentdocument" title="dom-iframe-contentDocument"><code>contentDocument</code></dfn>
1.145 mike 976: IDL attribute must return the <code><a href="dom.html#document">Document</a></code> object of the
1.1 mike 977: <a href="browsers.html#active-document">active document</a> of the <code><a href="#the-iframe-element">iframe</a></code> element's
1.204 mike 978: <a href="browsers.html#nested-browsing-context">nested browsing context</a>, if any, or null otherwise.</p>
1.1 mike 979:
980: <p>The <dfn id="dom-iframe-contentwindow" title="dom-iframe-contentWindow"><code>contentWindow</code></dfn>
981: IDL attribute must return the <code><a href="browsers.html#windowproxy">WindowProxy</a></code> object of the
982: <code><a href="#the-iframe-element">iframe</a></code> element's <a href="browsers.html#nested-browsing-context">nested browsing
1.204 mike 983: context</a>, if any, or null otherwise.</p>
1.1 mike 984:
1.230 mike 985: </div>
986:
987: <div class="example">
1.1 mike 988:
989: <p>Here is an example of a page using an <code><a href="#the-iframe-element">iframe</a></code> to
990: include advertising from an advertising broker:</p>
991:
992: <pre><iframe src="http://ads.example.com/?customerid=923513721&amp;format=banner"
993: width="468" height="60"></iframe></pre>
994:
1.230 mike 995: </div>
996:
997:
998:
999:
1000: </body></html>
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