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.
Public Method Summary
abstract LSInput |
Public Methods
public abstract LSInput resolveResource (String type, String namespaceURI, String publicId, String systemId, String baseURI)
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
type | The 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. |
---|---|
namespaceURI | The namespace of the resource being resolved, e.g. the target namespace of the XML Schema [XML Schema Part 1] when resolving XML Schema resources. |
publicId | The public identifier of the external entity being
referenced, or null if no public identifier was
supplied or if the resource is not an entity. |
systemId | The system identifier, a URI reference [IETF RFC 2396], of the
external resource being referenced, or null if no
system identifier was supplied. |
baseURI | The absolute base URI of the resource being parsed, or
null if there is no base URI. |
Returns
- A
LSInput
object describing the new input source, ornull
to request that the parser open a regular URI connection to the resource.