Package net.sf.saxon.pull

Class PullFilter

java.lang.Object
net.sf.saxon.pull.PullFilter
All Implemented Interfaces:
PullProvider
Direct Known Subclasses:
DocumentWrappingPullProvider, ElementNameTracker, PullNamespaceReducer, PullPushTee, PullTracer
public class PullFilter extends Object implements PullProvider
PullFilter is a pass-through filter class that links one PullProvider to another PullProvider in a pipeline. This class passes all events through completely unchanged. The class is designed so that subclasses can modify this behavior by altering some of the events.

  • Field Details

    • currentEvent

      protected PullEvent currentEvent

  • Constructor Details

    • PullFilter

      public PullFilter(PullProvider base)
      Create a PullFilter
      Parameters:
      base - the PullProvider to which requests are to be passed

  • Method Details

    • setPipelineConfiguration

      public void setPipelineConfiguration(PipelineConfiguration pipe)
      Set configuration information. This must only be called before any events have been read.
      Specified by:
      setPipelineConfiguration in interface PullProvider
      Parameters:
      pipe - the pipeline configuration

    • getPipelineConfiguration

      public PipelineConfiguration getPipelineConfiguration()
      Get configuration information.
      Specified by:
      getPipelineConfiguration in interface PullProvider
      Returns:
      the pipeline configuration

    • getNamePool

      public final NamePool getNamePool()
      Helper method to get the current namePool
      Returns:
      the NamePool

    • getUnderlyingProvider

      public PullProvider getUnderlyingProvider()
      Get the underlying PullProvider
      Returns:
      the underlying PullProvider

    • next

      public PullEvent next() throws XPathException
      Get the next event.

      Note that a subclass that overrides this method is responsible for ensuring that current() works properly. This can be achieved by setting the field currentEvent to the event returned by any call on next().

      Specified by:
      next in interface PullProvider
      Returns:
      an integer code indicating the type of event. The code PullEvent.END_OF_INPUT is returned at the end of the sequence.
      Throws:
      XPathException - if a dynamic error occurs

    • current

      public PullEvent current()
      Get the event most recently returned by next(), or by other calls that change the position, for example getStringValue() and skipToMatchingEnd(). This method does not change the position of the PullProvider.
      Specified by:
      current in interface PullProvider
      Returns:
      the current event

    • getAttributes

      public AttributeMap 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 AttributeMap are immutable.

      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
      Returns:
      an AttributeMap representing the attributes of the element that has just been notified.
      Throws:
      XPathException - if a dynamic error occurs

    • getNamespaceDeclarations

      public NamespaceBinding[] 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.

      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
      Returns:
      the namespace declarations associated with the current START_ELEMENT event.
      Throws:
      XPathException - if a dynamic error occurs

    • skipToMatchingEnd

      public PullEvent skipToMatchingEnd() throws XPathException
      Skip the current subtree. This method may be called only immediately after a START_DOCUMENT or START_ELEMENT event. This call returns the matching END_DOCUMENT or END_ELEMENT event; the next call on next() will return the event following the END_DOCUMENT or END_ELEMENT.
      Specified by:
      skipToMatchingEnd in interface PullProvider
      Returns:
      the matching END_DOCUMENT or END_ELEMENT event
      Throws:
      XPathException - if a dynamic error occurs

    • close

      public void close()
      Close the event reader. This indicates that no further events are required. It is not necessary to close an event reader after PullEvent.END_OF_INPUT has been reported, but it is recommended to close it if reading terminates prematurely. Once an event reader has been closed, the effect of further calls on next() is undefined.
      Specified by:
      close in interface PullProvider

    • getNodeName

      public NodeName getNodeName()
      Description copied from interface: PullProvider
      Get the NodeName identifying the name of the current node. This method can be used after the PullEvent.START_ELEMENT, PullEvent.PROCESSING_INSTRUCTION, PullEvent.ATTRIBUTE, or PullEvent.NAMESPACE events. With some PullProvider implementations, it can also be used after PullEvent.END_ELEMENT, but this is not guaranteed. 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 null.
      Specified by:
      getNodeName in interface PullProvider
      Returns:
      the NodeName. The NodeName can be used to obtain the prefix, local name, and namespace URI.

    • getStringValue

      public UnicodeString getStringValue() throws XPathException
      Get the string value of the current element, text node, processing-instruction, or top-level attribute or namespace node, or atomic value.

      In other situations the result is undefined and may result in an IllegalStateException.

      If the most recent event was a PullEvent.START_ELEMENT, this method causes the content of the element to be read. The next event notified will be the corresponding PullEvent.END_ELEMENT.

      Specified by:
      getStringValue in interface PullProvider
      Returns:
      the String Value of the node in question, defined according to the rules in the XPath data model.
      Throws:
      XPathException - if a dynamic error occurs

    • getAtomicValue

      public AtomicValue getAtomicValue()
      Get an atomic value. This call may be used only when the last event reported was ATOMIC_VALUE. This indicates that the PullProvider is reading a sequence that contains a free-standing atomic value; it is never used when reading the content of a node.
      Specified by:
      getAtomicValue in interface PullProvider
      Returns:
      the atomic value

    • getSchemaType

      public SchemaType getSchemaType()
      Get the type annotation of the current attribute or element node, or atomic value. The result of this method is undefined unless the most recent event was START_ELEMENT, ATTRIBUTE, or ATOMIC_VALUE.
      Specified by:
      getSchemaType in interface PullProvider
      Returns:
      the type annotation.

    • getSourceLocator

      public Location getSourceLocator()
      Get the location of the current event. For an event stream representing a real document, the location information should identify the location in the lexical XML source. For a constructed document, it should identify the location in the query or stylesheet that caused the node to be created. A value of null can be returned if no location information is available.
      Specified by:
      getSourceLocator in interface PullProvider
      Returns:
      the SourceLocator giving the location of the current event, or null if no location information is available

    • getUnparsedEntities

      public List<UnparsedEntity> getUnparsedEntities()
      Get a list of unparsed entities.
      Specified by:
      getUnparsedEntities in interface PullProvider
      Returns:
      a list of unparsed entities, or null if the information is not available, or an empty list if there are no unparsed entities.