CSS - content
The content
CSS property is used with the ::before
and ::after
pseudo-elements to generate content in an element. Objects inserted using the content
property are anonymous replaced elements.
Examples
Code sample - headings and quotes
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<h1>5</h1> <p> We shall start this with a quote from Sir Tim Berners-Lee, <q cite="http://www.w3.org/People/Berners-Lee/FAQ.html#Internet"> I was lucky enough to invent the Web at the time when the Internet already existed - and had for a decade and a half.</q> We must understand that there is nothing fundamentally wrong with building on the contributions of others. </p> <h1>6</h1> <p> Here we shall quote the Mozilla Manifesto, <q cite="http://www.mozilla.org/en-US/about/manifesto/"> Individuals must have the ability to shape the Internet and their own experiences on the Internet.</q> And so, we can infer that contributing to the open web, can protect our own individual experiences on it. </p>
CSS Content
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q { color: #00008B; font-style: italic; } q::before { content: open-quote } q::after { content: close-quote } h1::before { content: "Chapter "; }
Output
Code sample - content with multiple values adding an icon before a link
HTML Content
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<a href="http://www.mozilla.org/en-US/">Home Page</a>
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a::before{ content: url(https://www.mozilla.org/favicon.ico) " MOZILLA: "; font: x-small Arial,freeSans,sans-serif; color: gray; }
Output
Code sample - class based example
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<h2>Paperback best sellers</h2> <ol> <li>Political thriller</li> <li class="newEntry">Halloween Stories</li> <li>My Biography</li> <li class="newEntry">Vampire Romance</li> </ol>
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/* use a class rather that an element selector to give more flexibility. Below is a simple string example, but don't forget add a leading space in the text string for spacing purposes */ .newEntry::after { content: " New!"; color: red; }
Output
Code sample - rich link styling
HTML Content
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<ul> <li><a id="moz" href="http://www.mozilla.org/"> Mozilla Home Page</a></li> <li><a id="mdn" href="https://developer.mozilla.org/"> Mozilla Developer Network</a></li> </ul>
CSS Content
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a { text-decoration: none; border-bottom: 3px dotted navy; } a::after { content: " (" attr(id) ")"; } #moz::before { content:url(https://mozorg.cdn.mozilla.net/media/img/favicon.ico) ; } #mdn::before { content:url(https://mdn.mozillademos.org/files/7691/mdn-favicon16.png) ; } li { margin: 1em; }
Output
Syntax
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/* Keywords that cannot be combined with other values */ content: normal; content: none; /* <string> value, non-latin characters must be encoded */ /* e.g. \00A0 for */ content: 'prefix'; /* <uri> value */ content: url(http://www.example.com/test.png); /* <counter> values */ content: chapter_counter; /* attr() value linked to the HTML attribute value */ content: attr(value string); /* Language- and position-dependant keywords */ content: open-quote; content: close-quote; content: no-open-quote; content: no-close-quote; /* Except for normal and none, several values */ /* can be used simultaneously */ content: open-quote chapter_counter; /* Global values */ content: inherit; content: initial; content: unset;
Values
none
- The pseudo-element is not generated.
normal
- Computes to
none
for the:before
and:after
pseudo-elements. <string>
- Text content.
<uri>
orurl()
- The value is a URI that designates an external resource (such as an image). If the resource or image can't be displayed, it is either ignored or some placeholder shows up.
<counter>
- Counters may be specified with two different functions: 'counter()' or 'counters()'. The former has two forms: 'counter(name)' or 'counter(name, style)'. The generated text is the value of the innermost counter of the given name in scope at this pseudo-element; it is formatted in the indicated style ('decimal' by default). The latter function also has two forms: 'counters(name, string)' or 'counters(name, string, style)'. The generated text is the value of all counters with the given name in scope at this pseudo-element, from outermost to innermost separated by the specified string. The counters are rendered in the indicated style ('decimal' by default). See the section on automatic counters and numbering for more information. The name must not be 'none', 'inherit' or 'initial'. Such a name causes the declaration to be ignored.
attr(X)
- Returns the value of the element's attribute X as a string. If there is no attribute X, an empty string is returned. The case-sensitivity of attribute names depends on the document language.
open-quote
|close-quote
- These values are replaced by the appropriate string from the
quotes
property. no-open-quote
|no-close-quote
- Introduces no content, but increments (decrements) the level of nesting for quotes.
Formal syntax
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normal <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> none <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> <a title="Brackets" href="css/value_definition_syntax#brackets">[</a> <a title="" href="css/string"><string></a> <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> <a title="" href="css/url"><uri></a> <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> <counter> <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> attr() <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> open-quote <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> close-quote <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> no-open-quote <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> no-close-quote <a title="Brackets" href="css/value_definition_syntax#brackets">]</a><a title="Plus" href="css/value_definition_syntax#plus_(.2b)">+</a>
Description
The content
CSS property is used with the ::before
and ::after
pseudo-elements to generate content in an element. Objects inserted using the content
property are anonymous replaced elements.
Initial value | normal |
---|---|
Applies to | ::before and ::after pseudo-elements |
Inherited | no |
Media | all |
Computed value | On elements, always computes to normal . On ::before and ::after , if normal is specified, computes to none . Otherwise, for URI values, the absolute URI; for attr() values, the resulting string; for other keywords, as specified. |
Animatable | no |
Canonical order | the unique non-ambiguous order defined by the formal grammar |
See Also
Specifications
Specification | Status | Comment |
---|---|---|
CSS Level 2 (Revision 1) The definition of 'content' in that specification. |
Recommendation | Initial definition |
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 1.0 | 1.0 (1.7 or earlier) | 8.0 | 4.0 | 1.0 |
url() support |
1.0 | 1.0 (1.7 or earlier) | 8.0 | 7.0 | 1.0 |
Feature | Android | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|
Basic support | 1.0 | 1.0 (1.0) | 8.0 | 9.5 | 1.0 |
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/css/content