CSS namespaces
The CSS namespaces module defines the syntax for using namespaces in CSS.
CSS isn't just for styling HTML. A stylesheet may be used to style SVG, MathML, XML, or HTML, each of which has a different namespace or a document containing multiple namespaces.
The @namespace at-rule defined in this module enables distinguishing between same-named elements in different namespaces. Element tag names are not unique to a single language. For example, the <a> element isn't limited to HTML. You may want to style the <a>s within your SVGs differently from the links in your HTML. You also will likely want to ensure that querySelectorAll("a") selects the right kind of element. Namespacing can help.
The @namespace rule is used for declaring a default namespace and for binding namespaces to namespace prefixes. The namespaces module also defines the syntax for using these prefixes to represent namespace-qualified names. That's it. What a name means or if the name is even valid depends on the context and host language.
Reference
At-rules
Guides
- Namespaces crash course
-
Deep dive into what a namespace is and how they are used in XML and XML-based markup languages.
Related concepts
- CSS namespace separator (
|) combinator - CSS type selectors
- CSS universal selector
CSSNamespaceRuleinterfaceCSSNamespaceRule.namespaceURIpropertyCSSNamespaceRule.prefixproperty
Document.createAttributeNS()methodDocument.createElementNS()methodDocument.getElementsByTagNameNS()methodElement.getAttributeNodeNS()methodElement.getAttributeNS()methodElement.getElementsByTagNameNS()methodElement.hasAttributeNS()methodElement.namespaceURIpropertyElement.removeAttributeNS()methodElement.setAttributeNS()methodElement.setAttributeNodeNS()methodNamedNodeMap.getNamedItemNS()methodNamedNodeMap.removeNamedItemNS()methodNamedNodeMap.setNamedItemNS()method- Namespace glossary term
Specifications
| Specification |
|---|
| CSS Namespaces Module Level 3 # declaration |
Browser compatibility
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