ractive/src/virtualdom/items/Element/Attribute/helpers/determineNameAndNamespace.js

Next-generation DOM manipulation

import namespaces from 'config/namespaces';
import enforceCase from 'virtualdom/items/Element/shared/enforceCase';

export default function ( attribute, name ) {
	var colonIndex, namespacePrefix;

	// are we dealing with a namespaced attribute, e.g. xlink:href?
	colonIndex = name.indexOf( ':' );
	if ( colonIndex !== -1 ) {

		// looks like we are, yes...
		namespacePrefix = name.substr( 0, colonIndex );

		// ...unless it's a namespace *declaration*, which we ignore (on the assumption
		// that only valid namespaces will be used)
		if ( namespacePrefix !== 'xmlns' ) {
			name = name.substring( colonIndex + 1 );

			attribute.name = enforceCase( name );
			attribute.namespace = namespaces[ namespacePrefix.toLowerCase() ];

			if ( !attribute.namespace ) {
				throw 'Unknown namespace ("' + namespacePrefix + '")';
			}

			return;
		}
	}

	// SVG attribute names are case sensitive
	attribute.name = ( attribute.element.namespace !== namespaces.html ? enforceCase( name ) : name );
}