net.sf.saxon.pull
Class PullNamespaceReducer

java.lang.Object
  net.sf.saxon.pull.PullFilter
      net.sf.saxon.pull.PullNamespaceReducer

All Implemented Interfaces:

NamespaceResolver, PullProvider

public class PullNamespaceReducer
extends PullFilter
implements NamespaceResolver

PullNamespaceReducer is a PullFilter responsible for removing duplicate namespace declarations. It also performs namespace fixup: that is, it ensures that the namespaces used in element and attribute names are all declared.

This class is derived from, and contains much common code with, the NamespaceReducer in the push pipeline. (In the push version, however, namespace fixup is not performed by the NamespaceReducer, but by the ComplexContentOutputter).

See Also:

NamespaceReducer

Field Summary

Fields inherited from interface net.sf.saxon.pull.PullProvider

ATOMIC_VALUE, ATTRIBUTE, COMMENT, END_DOCUMENT, END_ELEMENT, END_OF_INPUT, NAMESPACE, PROCESSING_INSTRUCTION, START_DOCUMENT, START_ELEMENT, START_OF_INPUT, TEXT

Constructor Summary

PullNamespaceReducer(PullProvider base)
Create a namespace reducer for a pull pipeline

Method Summary

void	endElement() endElement: Discard the namespaces declared on this element.
AttributeCollection	getAttributes() Get the attributes associated with the current element.
int	getNameCode() Get the nameCode identifying the name of the current node.
NamespaceDeclarations	getNamespaceDeclarations() Get the namespace declarations associated with the current element.
String	getURIForPrefix(String prefix, boolean useDefault) Get the namespace URI corresponding to a given prefix.
Iterator	iteratePrefixes() Get an iterator over all the prefixes declared in this namespace context.
int	next() next(): handle next event.

Methods inherited from class net.sf.saxon.pull.PullFilter

close, current, getAtomicValue, getFingerprint, getNamePool, getPipelineConfiguration, getSourceLocator, getStringValue, getTypeAnnotation, getUnderlyingProvider, getUnparsedEntities, setPipelineConfiguration, skipToMatchingEnd

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PullNamespaceReducer

public PullNamespaceReducer(PullProvider base)

Create a namespace reducer for a pull pipeline

Parameters:

base - the next stage in the pipeline, from which events are read

Method Detail

next

public int next()
         throws XPathException

next(): handle next event. The START_ELEMENT event removes redundant namespace declarations, and possibly adds an xmlns="" undeclaration.

Specified by:

next in interface PullProvider

Overrides:

next in class PullFilter

Returns:

an integer code indicating the type of event. The code PullProvider.END_OF_INPUT is returned at the end of the sequence.

Throws:

XPathException

getNameCode

public int getNameCode()

Get the nameCode identifying the name of the current node. This method can be used after the PullProvider.START_ELEMENT, PullProvider.PROCESSING_INSTRUCTION, PullProvider.ATTRIBUTE, or PullProvider.NAMESPACE events. With some PullProvider implementations, including this one, it can also be used after PullProvider.END_ELEMENT If called at other times, the result is undefined and may result in an IllegalStateException. If called when the current node is an unnamed namespace node (a node representing the default namespace) the returned value is -1.

Specified by:

getNameCode in interface PullProvider

Overrides:

getNameCode in class PullFilter

Returns:

the nameCode. The nameCode can be used to obtain the prefix, local name, and namespace URI from the name pool.

getAttributes

public AttributeCollection getAttributes()
                                  throws XPathException

Get the attributes associated with the current element. This method must be called only after a START_ELEMENT event has been notified. The contents of the returned AttributeCollection are guaranteed to remain unchanged until the next START_ELEMENT event, but may be modified thereafter. The object should not be modified by the client.

Attributes may be read before or after reading the namespaces of an element, but must not be read after the first child node has been read, or after calling one of the methods skipToEnd(), getStringValue(), or getTypedValue().

Specified by:

getAttributes in interface PullProvider

Overrides:

getAttributes in class PullFilter

Returns:

an AttributeCollection representing the attributes of the element that has just been notified.

Throws:

XPathException

getNamespaceDeclarations

public NamespaceDeclarations getNamespaceDeclarations()
                                               throws XPathException

Get the namespace declarations associated with the current element. This method must be called only after a START_ELEMENT event has been notified. In the case of a top-level START_ELEMENT event (that is, an element that either has no parent node, or whose parent is not included in the sequence being read), the NamespaceDeclarations object returned will contain a namespace declaration for each namespace that is in-scope for this element node. In the case of a non-top-level element, the NamespaceDeclarations will contain a set of namespace declarations and undeclarations, representing the differences between this element and its parent.

This class extends the semantics of the PullProvider interface by allowing this method to be called also after an END_ELEMENT event. This is to support PullToStax, which requires this functionality. In this situation it returns the namespaces declared on the startElement associated with the element that has just ended.

It is permissible for this method to return namespace declarations that are redundant.

The NamespaceDeclarations object is guaranteed to remain unchanged until the next START_ELEMENT event, but may then be overwritten. The object should not be modified by the client.

Namespaces may be read before or after reading the attributes of an element, but must not be read after the first child node has been read, or after calling one of the methods skipToEnd(), getStringValue(), or getTypedValue().

*

Specified by:

getNamespaceDeclarations in interface PullProvider

Overrides:

getNamespaceDeclarations in class PullFilter

Returns:

the namespace declarations associated with the current START_ELEMENT event.

Throws:

XPathException

endElement

public void endElement()
                throws XPathException

endElement: Discard the namespaces declared on this element. Note, however, that for the benefit of PullToStax, the namespaces that go out of scope on this endElement are available so long as the endElement is the current event

Throws:

XPathException

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