com.saxonica.ee.stream.feed

Class EmptiableElementFeed

java.lang.Object

com.saxonica.ee.stream.feed.ItemFeed

com.saxonica.ee.stream.feed.ComplexNodeEventFeed

com.saxonica.ee.stream.feed.EmptiableElementFeed

All Implemented Interfaces:

Feed

public class EmptiableElementFeed
extends ComplexNodeEventFeed

This event feed supports instructions that create an element node with an on-empty fallback. The event representing the start of the element is not written to the destination receiver immediately, but only when the first content is encountered.

The instruction-dependent code is contained in the processLeft() and processRight() methods

Constructor Summary

Constructors

Constructor and Description
EmptiableElementFeed(Expression exp, Feed parentExpressionFeed, XPathContext context)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Finish evaluating the expression.
void	open(Terminator terminator) Start evaluating the expression.
void	processItem(Item item) Supply one item towards the streamed input of the expression
protected void	processLeft(XPathContext context) In streaming mode, process the first half of the instruction (for example, to start a new document or element)
protected void	processRight(XPathContext context) In streaming mode, process the right half of the instruction (for example, to end a new document or element)

Methods inherited from class com.saxonica.ee.stream.feed.ComplexNodeEventFeed

getReceiver, setReceiver

Methods inherited from class com.saxonica.ee.stream.feed.ItemFeed

dynamicError, endSelectedParentNode, getContext, getExpression, getPipelineConfiguration, getResult, getTerminator, hasFailed, processItems, setExpression, setHasFailed, setPipelineConfiguration, setTerminator, startSelectedParentNode

Methods inherited from class java.lang.Object

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

Constructor Detail

EmptiableElementFeed

public EmptiableElementFeed(Expression exp,
                    Feed parentExpressionFeed,
                    XPathContext context)

Method Detail

open

public void open(Terminator terminator)
          throws XPathException

Description copied from class: ItemFeed

Start evaluating the expression. The default implementation does nothing.

Specified by:

open in interface Feed

Overrides:

open in class ComplexNodeEventFeed

Parameters:

terminator - used to achieve early exit

Throws:

XPathException - if a dynamic error occurs

processItem

public void processItem(Item item)
                 throws XPathException

Description copied from class: ItemFeed

Supply one item towards the streamed input of the expression

Specified by:

processItem in interface Feed

Overrides:

processItem in class ComplexNodeEventFeed

Parameters:

item - the item to be supplied

Throws:

XPathException - May be raised if a dynamic error occurs

close

public void close()
           throws XPathException

Description copied from class: ItemFeed

Finish evaluating the expression. The default implementation does nothing.

Specified by:

close in interface Feed

Overrides:

close in class ComplexNodeEventFeed

Throws:

XPathException - if a dynamic error occurs

processLeft

protected void processLeft(XPathContext context)
                    throws XPathException

In streaming mode, process the first half of the instruction (for example, to start a new document or element)

Specified by:

processLeft in class ComplexNodeEventFeed

Parameters:

context - The dynamic context

Throws:

XPathException - if a dynamic error occurs

processRight

protected void processRight(XPathContext context)
                     throws XPathException

In streaming mode, process the right half of the instruction (for example, to end a new document or element)

Specified by:

processRight in class ComplexNodeEventFeed

Parameters:

context - The dynamic context

Throws:

XPathException - if a dynamic error occurs