[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Can anyURI be empty?
Joe Fawcett wrote: > I'm having trouble working out from > http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#anyURI > [shown at bottom of mail] > means that anyURI can be an empty string, can someone elucidate? If it couldn't, it would be wrong. An empty string is a valid URI. Bob Foster > Thanks > > Joe > > > Definition: > 3.2.17 anyURI > [Definition:] anyURI represents a Uniform Resource Identifier Reference > (URI). An anyURI value can be absolute or relative, and may have an optional > fragment identifier (i.e., it may be a URI Reference). This type should be > used to specify the intention that the value fulfills the role of a URI as > defined by [RFC 2396], as amended by [RFC 2732]. > > The mapping from anyURI values to URIs is as defined in Section 5.4 Locator > Attribute of [XML Linking Language] (see also Section 8 Character Encoding > in URI References of [Character Model]). This means that a wide range of > internationalized resource identifiers can be specified when an anyURI is > called for, and still be understood as URIs per [RFC 2396], as amended by > [RFC 2732], where appropriate to identify resources. > > NOTE: Each URI scheme imposes specialized syntax rules for URIs in that > scheme, including restrictions on the syntax of allowed fragement > identifiers. Because it is impractical for processors to check that a value > is a context-appropriate URI reference, this specification follows the lead > of [RFC 2396] (as amended by [RFC 2732]) in this matter: such rules and > restrictions are not part of type validity and are not checked by ·minimally > conforming· processors. Thus in practice the above definition imposes only > very modest obligations on ·minimally conforming· processors. > 3.2.17.1 Lexical representation > The ·lexical space· of anyURI is finite-length character sequences which, > when the algorithm defined in Section 5.4 of [XML Linking Language] is > applied to them, result in strings which are legal URIs according to [RFC > 2396], as amended by [RFC 2732]. > > NOTE: Spaces are, in principle, allowed in the ·lexical space· of anyURI, > however, their use is highly discouraged (unless they are encoded by %20). > 3.2.17.2 Constraining facets > anyURI has the following ·constraining facets·: > > a.. length > b.. minLength > c.. maxLength > d.. pattern > e.. enumeration > f.. whiteSpace > > ----------------------------------------------------------------- > The xml-dev list is sponsored by XML.org <http://www.xml.org>, an > initiative of OASIS <http://www.oasis-open.org> > > The list archives are at http://lists.xml.org/archives/xml-dev/ > > To subscribe or unsubscribe from this list use the subscription > manager: <http://www.oasis-open.org/mlmanage/index.php> > >
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