unicode-bidi property CSS Reference



Definition and Usage

The unicode-bidi CSS property together with the direction property relates to the handling of bidirectional text in a document. For example, if a block of text contains both left-to-right and right-to-left text then the user-agent uses a complex Unicode algorithm to decide how to display the text. This property overrides this algorithm and allows the developer to control the text embedding.

The unicode-bidi and direction properties are the two only properties that are not affected by the all shorthand.

Note: This property is intended for DTD designers. Web designers and similar authors should not override it.

  • Initial normal
  • Applies to all elements, though some values have no effect on non-inline elements
  • Inherited no
  • Media visual
  • Computed Value as specified
  • Animatable no
  • Canonical order the unique non-ambiguous order defined by the formal grammar

Syntax

Formal syntax: normal | embed | isolate | bidi-override | isolate-override | plaintext
unicode-bidi: normal
unicode-bidi: embed
unicode-bidi: isolate
unicode-bidi: bidi-override
unicode-bidi: isolate-override
unicode-bidi: plaintext
unicode-bidi: inherit

Values

normal
The element does not offer a additional level of embedding with respect to the bidirectional algorithm. For inline elements implicit reordering works across element boundaries.
embed
If the element is inline, this value opens an additional level of embedding with respect to the bidirectional algorithm. The direction of this embedding level is given by the direction property.
bidi-override
For inline elements this creates an override. For block container elements this creates an override for inline-level descendants not within another block container element. This means that inside the element, reordering is strictly in sequence according to the direction property; the implicit part of the bidirectional algorithm is ignored.
isolate
This keyword indicates that the element's container directionality should be calculated without considering the content of this element. The element is therefore isolated from its siblings. When applying its bidirectional-resolution algorithm, its container element treats it as one or several U+FFFC Object Replacement Character, i.e. like an image.
isolate-override
This keyword applies the isolation behavior of the isolate keyword to the surrounding content and the override behavior of the bidi-override keyword to the inner content.
plaintext

This keyword makes the elements directionality calculated without considering its parent bidirectional state or the value of the direction property. The directionality is calculated using the P2 and P3 rules of the Unicode Bidirectional Algorithm.

This value allows to display data which has already formatted using a tool following the Unicode Bidirectional Algorithm.


Examples

.bible-quote {
  direction: rtl;
  unicode-bidi: embed;
}

Compatibility

Desktop browsers

FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari (WebKit)
Basic support2.01.0 (1.7 or earlier)5.59.21.3
isolate16 -webkit10.0 (10) -mozNot supportedNot supportedNot supported
plaintextNot supported10.0 (10) -mozNot supportedNot supportedNot supported
isolate-overrideNot supported17.0 (17) -mozNot supportedNot supportedNot supported

Mobile browsers

FeatureAndroidFirefox Mobile (Gecko)IE PhoneOpera MobileSafari Mobile
Basic support1.01.0 (1.0)683.1
isolateNA10.0 (10) -mozNot supportedNot supportedNot supported
plaintextNot supported10.0 (10) -mozNot supportedNot supportedNot supported
isolate-overrideNot supported17.0 (17) -mozNot supportedNot supportedNot supported

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