Class NamespaceMaintainer

java.lang.Object
net.sf.saxon.evpull.NamespaceMaintainer
All Implemented Interfaces:
EventIterator, PullEvent, NamespaceResolver

public class NamespaceMaintainer extends Object implements EventIterator, NamespaceResolver
NamespaceMaintainer is an EventIterator responsible for maintaining namespace context in an event stream. It allows the current namespace context to be determined at any time while processing the stream of events.

Note that this class merely provides the service of keeping track of which namespaces are currently in scope. It does not attempt to remove duplicate namespace declarations, and it does not perform namespace fixup.

  • Constructor Details

    • NamespaceMaintainer

      public NamespaceMaintainer(EventIterator base, NamePool namePool)
      Create a namespace context for a pull-events pipeline
      Parameters:
      base - the previous stage in the pipeline, from which events are read
      namePool - the NamePool
  • Method Details

    • isFlatSequence

      public boolean isFlatSequence()
      Determine whether the EventIterator returns a flat sequence of events, or whether it can return nested event iterators
      Specified by:
      isFlatSequence in interface EventIterator
      Returns:
      true if the next() method is guaranteed never to return an EventIterator
    • next

      public PullEvent next() throws XPathException
      Get the next event in the sequence
      Specified by:
      next in interface EventIterator
      Returns:
      the next event, or null when the sequence is exhausted. Note that since an EventIterator is itself a PullEvent, this method may return a nested iterator.
      Throws:
      XPathException - if a dynamic evaluation error occurs
    • getURICode

      protected short getURICode(short prefixCode)
      Get the URI code corresponding to a given prefix code, by searching the in-scope namespaces. This is a service provided to subclasses.
      Parameters:
      prefixCode - the 16-bit prefix code required
      Returns:
      the 16-bit URI code, or -1 if the prefix is not found
    • 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 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