LSResourceResolver provides a way for applications to redirect references to external resources.

Applications needing to implement custom handling for external resources can implement this interface and register their implementation by setting the "resource-resolver" parameter of DOMConfiguration objects attached to LSParser and LSSerializer. It can also be register on DOMConfiguration objects attached to Document if the "LS" feature is supported.

The LSParser will then allow the application to intercept any external entities, including the external DTD subset and external parameter entities, before including them. The top-level document entity is never passed to the resolveResource method.

Many DOM applications will not need to implement this interface, but it will be especially useful for applications that build XML documents from databases or other specialized input sources, or for applications that use URNs.

Note: LSResourceResolver is based on the SAX2 [SAX] EntityResolver interface.

See also the Document Object Model (DOM) Level 3 Load and Save Specification.

Allow the application to resolve external resources.
The LSParser will call this method before opening any external resource, including the external DTD subset, external entities referenced within the DTD, and external entities referenced within the document element (however, the top-level document entity is not passed to this method). The application may then request that the LSParser resolve the external resource itself, that it use an alternative URI, or that it use an entirely different input source.
Application writers can use this method to redirect external system identifiers to secure and/or local URI, to look up public identifiers in a catalogue, or to read an entity from a database or other input source (including, for example, a dialog box).
Parameters
typeThe type of the resource being resolved. For XML [XML 1.0] resources (i.e. entities), applications must use the value "http://www.w3.org/TR/REC-xml". For XML Schema [XML Schema Part 1] , applications must use the value "http://www.w3.org/2001/XMLSchema". Other types of resources are outside the scope of this specification and therefore should recommend an absolute URI in order to use this method.
namespaceURIThe namespace of the resource being resolved, e.g. the target namespace of the XML Schema [XML Schema Part 1] when resolving XML Schema resources.
publicIdThe public identifier of the external entity being referenced, or null if no public identifier was supplied or if the resource is not an entity.
systemIdThe system identifier, a URI reference [IETF RFC 2396], of the external resource being referenced, or null if no system identifier was supplied.
baseURIThe absolute base URI of the resource being parsed, or null if there is no base URI.
Return
A LSInput object describing the new input source, or null to request that the parser open a regular URI connection to the resource.