Class NamespaceReducer

All Implemented Interfaces:
Result, Receiver, NamespaceResolver

public class NamespaceReducer extends ProxyReceiver implements NamespaceResolver
NamespaceReducer is a ProxyReceiver responsible for removing duplicate namespace declarations. It also ensures that an xmlns="" undeclaration is output when necessary. Used on its own, the NamespaceReducer simply eliminates unwanted namespace declarations. It can also be subclassed, in which case the subclass can use the services of the NamespaceReducer to resolve QNames.

The NamespaceReducer also validates namespace-sensitive content.

  • Constructor Details

    • NamespaceReducer

      public NamespaceReducer(Receiver next)
      Create a NamespaceReducer
      Parameters:
      next - the Receiver to which events will be passed after namespace reduction
  • Method Details

    • startElement

      public void startElement(NodeName elemName, SchemaType typeCode, int locationId, int properties) throws XPathException
      startElement. This call removes redundant namespace declarations, and possibly adds an xmlns="" undeclaration.
      Specified by:
      startElement in interface Receiver
      Overrides:
      startElement in class ProxyReceiver
      Parameters:
      elemName - integer code identifying the name of the element within the name pool.
      typeCode - integer code identifying the element's type within the name pool.
      locationId - an integer which can be interpreted using a LocationProvider to return information such as line number and system ID. If no location information is available, the value zero is supplied.
      properties - properties of the element node
      Throws:
      XPathException - if an error occurs
    • namespace

      public void namespace(NamespaceBinding namespaceBinding, int properties) throws XPathException
      Output a namespace node (binding)
      Specified by:
      namespace in interface Receiver
      Overrides:
      namespace in class ProxyReceiver
      Parameters:
      namespaceBinding - the prefix/uri pair to be output
      properties - the properties of the namespace binding
      Throws:
      XPathException - if any downstream error occurs
    • startContent

      public void startContent() throws XPathException
      startContent: Add any namespace undeclarations needed to stop namespaces being inherited from parent elements
      Specified by:
      startContent in interface Receiver
      Overrides:
      startContent in class ProxyReceiver
      Throws:
      XPathException - if an error occurs
    • endElement

      public void endElement() throws XPathException
      endElement: Discard the namespaces declared on this element.
      Specified by:
      endElement in interface Receiver
      Overrides:
      endElement in class ProxyReceiver
      Throws:
      XPathException - if an error occurs
    • getURIForPrefix

      public String getURIForPrefix(String prefix, boolean useDefault)
      Get the namespace URI corresponding to a given prefix. Return null if the prefix is not in scope.
      Specified by:
      getURIForPrefix in interface NamespaceResolver
      Parameters:
      prefix - the namespace prefix
      useDefault - true if the default namespace is to be used when the prefix is ""
      Returns:
      the uri for the namespace, or null if the prefix is not in scope
    • iteratePrefixes

      public Iterator<String> iteratePrefixes()
      Get an iterator over all the prefixes declared in this namespace context. This will include the default namespace (prefix="") and the XML namespace where appropriate
      Specified by:
      iteratePrefixes in interface NamespaceResolver
      Returns:
      an iterator over all the prefixes for which a namespace binding exists, including the zero-length string to represent the null/absent prefix if it is bound