com.saxonica.stream.watch

Class GroupedItemStoppingFeed

java.lang.Object

com.saxonica.stream.feed.ItemFeed

com.saxonica.stream.watch.GroupedItemStoppingFeed

All Implemented Interfaces:

Feed

public class GroupedItemStoppingFeed
extends ItemFeed

This feed supports xsl:for-each-group in streaming mode. The essence of this class is that its open() and close() methods do nothing. These methods are called automatically before and after processing each item in the group, and by doing nothing, they ensure that the pre-group and post-group processing does not happen before and after processing each item in the group. Instead, the GroupingFeed triggers the pre-group and post-group processing directly.

Constructor Summary

Constructors

Constructor and Description
GroupedItemStoppingFeed(Expression expression, Feed result, Stack<XPathContext> contextStack)

Method Summary

Methods

Modifier and Type	Method and Description
void	append(Item item) Supply one item towards the streamed input of the expression (that is, one item of the grouping population)
void	close() Finish evaluating the expression.
void	open() Called at the start of processing each item selected by the for-each-group instruction

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

getContext, getContextStack, getExpression, getPipelineConfiguration, getResult, setPipelineConfiguration

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupedItemStoppingFeed

public GroupedItemStoppingFeed(Expression expression,
                       Feed result,
                       Stack<XPathContext> contextStack)

Method Detail

open

public void open()
          throws XPathException

Called at the start of processing each item selected by the for-each-group instruction

Specified by:

open in interface Feed

Overrides:

open in class ItemFeed

Throws:

XPathException

append

public void append(Item item)
            throws XPathException

Supply one item towards the streamed input of the expression (that is, one item of the grouping population)

Specified by:

append in interface Feed

Specified by:

append in class ItemFeed

Parameters:

item - the next item from the population

Throws:

XPathException - to report any failure

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 ItemFeed

Throws:

XPathException - if a dynamic error occurs