Package com.saxonica.ee.stream.feed
Class FilteringFeed
- java.lang.Object
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- net.sf.saxon.event.Outputter
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- net.sf.saxon.event.ProxyOutputter
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- com.saxonica.ee.stream.feed.ItemFeed
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- com.saxonica.ee.stream.feed.GroundedItemFeed
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- com.saxonica.ee.stream.feed.FilteringFeed
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- All Implemented Interfaces:
javax.xml.transform.Result
,Receiver
public class FilteringFeed extends GroundedItemFeed
This class selects a subset of the items, nodes, or events selected by some supplying expression. The subset is determined as a function of the position of the node (among all the nodes matched since the watch was activated).
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Nested Class Summary
Nested Classes Modifier and Type Class Description static interface
FilteringFeed.Filter
Interface defining the filter function, to be implemented by the callerstatic class
FilteringFeed.OpaqueFilter
A filter that matches nothingstatic class
FilteringFeed.TransparentFilter
A filter that matches everything
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Field Summary
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Fields inherited from class net.sf.saxon.event.Outputter
pipelineConfiguration, systemId
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Constructor Summary
Constructors Constructor Description FilteringFeed(ItemFeed nextFeed, XPathContext context, FilteringFeed.Filter filter)
Create a filtering feed
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
append(Item item)
Supply one item towards the streamed input of the expressionvoid
close()
Finish evaluating the expression.void
endSelectedParentNode(Location locationId)
Signal that the endElement event has occurred for the element whose startElement event caused the Watch to be activated.void
open(Terminator terminator)
Start evaluating the expression.Receiver
startSelectedParentNode(FleetingParentNode node, Location locationId)
Signal that an element or document node has been found that matches the selection that this Watch is looking for.-
Methods inherited from class com.saxonica.ee.stream.feed.GroundedItemFeed
attribute, characters, comment, endDocument, endElement, namespace, processingInstruction, setUnparsedEntity, startContent, startDocument, startElement, startElement
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Methods inherited from class com.saxonica.ee.stream.feed.ItemFeed
append, dynamicError, getContext, getExpression, getResult, getTerminator, hasFailed, processItems, setExpression, setHasFailed, setTerminator
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Methods inherited from class net.sf.saxon.event.ProxyOutputter
getNextOutputter, open, setLocation, usesTypeAnnotations
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Methods inherited from class net.sf.saxon.event.Outputter
getConfiguration, getPipelineConfiguration, getStringReceiver, getSystemId, namespaces, setPipelineConfiguration, setSystemId
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface net.sf.saxon.event.Receiver
handlesAppend
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Constructor Detail
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FilteringFeed
public FilteringFeed(ItemFeed nextFeed, XPathContext context, FilteringFeed.Filter filter)
Create a filtering feed- Parameters:
nextFeed
- the feed to which the filtered items/events will be sentfilter
- a function which tests whether the item/node/event at a particular position is to be selected
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Method Detail
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open
public void open(Terminator terminator) throws XPathException
Description copied from class:ItemFeed
Start evaluating the expression. The default implementation does nothing.- Overrides:
open
in classItemFeed
- Parameters:
terminator
- used to achieve early exit- Throws:
XPathException
- if a dynamic error occurs
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startSelectedParentNode
public Receiver startSelectedParentNode(FleetingParentNode node, Location locationId) throws XPathException
Description copied from class:ItemFeed
Signal that an element or document node has been found that matches the selection that this Watch is looking for. This method is called by the WatchManager while processing the startElement or startDocument event that matches the selection.- Overrides:
startSelectedParentNode
in classItemFeed
- Parameters:
node
- the element or document node whose start event has been matchedlocationId
- the location associated with the element or document node (may be the location of the instruction that created it)- Returns:
- a Receiver to be notified of all events starting with the startElement/startDocument event for the matched element, and ending with the endElement event for that element; or null if this feature is not required.
- Throws:
XPathException
- May be raised if a dynamic error occurs
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endSelectedParentNode
public void endSelectedParentNode(Location locationId) throws XPathException
Description copied from class:ItemFeed
Signal that the endElement event has occurred for the element whose startElement event caused the Watch to be activated.- Overrides:
endSelectedParentNode
in classItemFeed
- Parameters:
locationId
- the location of the element- Throws:
XPathException
- May be raised if a constraint implemented by this Watch is violated
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append
public void append(Item item) throws XPathException
Description copied from class:ItemFeed
Supply one item towards the streamed input of the expression- Specified by:
append
in interfaceReceiver
- Specified by:
append
in classItemFeed
- Parameters:
item
- the item to be supplied- Throws:
XPathException
- if the operation fails
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close
public void close() throws XPathException
Description copied from class:ItemFeed
Finish evaluating the expression.- Specified by:
close
in interfaceReceiver
- Overrides:
close
in classItemFeed
- Throws:
XPathException
- if a dynamic error occurs
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