Package net.sf.saxon.style

Class UseWhenFilter

java.lang.Object

net.sf.saxon.event.SequenceReceiver

net.sf.saxon.event.ProxyReceiver

net.sf.saxon.style.UseWhenFilter

All Implemented Interfaces:

javax.xml.transform.Result, Receiver

public class UseWhenFilter
extends ProxyReceiver

This is a filter inserted into the input pipeline for processing stylesheet modules, whose task is to evaluate use-when expressions and discard those parts of the stylesheet module for which the use-when attribute evaluates to false.

Originally, with XSLT 2.0, this class did use-when filtering and very little else. In XSLT 3.0 its role has expanded: it evaluates shadow attributes and static variables, and collects information about package dependencies.

Field Summary

Fields inherited from class net.sf.saxon.event.ProxyReceiver

nextReceiver

Fields inherited from class net.sf.saxon.event.SequenceReceiver

pipelineConfiguration, previousAtomic, systemId

Fields inherited from interface javax.xml.transform.Result

PI_DISABLE_OUTPUT_ESCAPING, PI_ENABLE_OUTPUT_ESCAPING

Constructor Summary

Constructors

Constructor	Description
UseWhenFilter(Compilation compilation, Receiver next, NestedIntegerValue precedence)	Create a UseWhenFilter

Method Summary

Modifier and Type	Method	Description
void	characters(java.lang.CharSequence chars, Location locationId, int properties)	Character data
void	comment(java.lang.CharSequence chars, Location locationId, int properties)	Output a comment
void	endElement()	End of element
Sequence	evaluateStatic(java.lang.String expression, Location locationId, UseWhenStaticContext staticContext)	Evaluate a static expression (to initialize a static variable)
void	open()	Start of document
void	processingInstruction(java.lang.String target, java.lang.CharSequence data, Location locationId, int properties)	Processing Instruction
void	startElement(NodeName elemName, SchemaType type, AttributeMap attributes, NamespaceMap namespaces, Location location, int properties)	Notify the start of an element.

Methods inherited from class net.sf.saxon.event.ProxyReceiver

append, close, endDocument, getNamePool, getNextReceiver, setPipelineConfiguration, setSystemId, setUnderlyingReceiver, setUnparsedEntity, startDocument, usesTypeAnnotations

Methods inherited from class net.sf.saxon.event.SequenceReceiver

append, decompose, flatten, getConfiguration, getErrorCodeForDecomposingFunctionItems, getPipelineConfiguration, getSystemId, handlesAppend

Methods inherited from class java.lang.Object

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

Constructor Detail

UseWhenFilter

public UseWhenFilter(Compilation compilation,
                     Receiver next,
                     NestedIntegerValue precedence)

Create a UseWhenFilter

Parameters:

compilation - the compilation episode

next - the next receiver in the pipeline

precedence - the import precedence expressed as a dotted-decimal integer, e.g. 1.4.6

Method Detail

open

public void open()
          throws XPathException

Start of document

Specified by:

open in interface Receiver

Overrides:

open in class ProxyReceiver

Throws:

XPathException - if an error occurs

startElement

public void startElement(NodeName elemName,
                         SchemaType type,
                         AttributeMap attributes,
                         NamespaceMap namespaces,
                         Location location,
                         int properties)
                  throws XPathException

Notify the start of an element.

Specified by:

startElement in interface Receiver

Overrides:

startElement in class ProxyReceiver

Parameters:

elemName - the name of the element.

type - the type annotation of the element.

attributes - the attributes of this element

namespaces - the in-scope namespaces of this element: generally this is all the in-scope namespaces, without relying on inheriting namespaces from parent elements

location - an object providing information about the module, line, and column where the node originated

properties - bit-significant properties of the element node. If there are no relevant properties, zero is supplied. The definitions of the bits are in class ReceiverOption

Throws:

XPathException - if an error occurs

endElement

public void endElement()
                throws XPathException

End of element

Specified by:

endElement in interface Receiver

Overrides:

endElement in class ProxyReceiver

Throws:

XPathException - if an error occurs

characters

public void characters(java.lang.CharSequence chars,
                       Location locationId,
                       int properties)
                throws XPathException

Character data

Specified by:

characters in interface Receiver

Overrides:

characters in class ProxyReceiver

Parameters:

chars - The characters

locationId - provides information such as line number and system ID.

properties - Bit significant value. The following bits are defined:

DISABLE_ESCAPING

Disable escaping for this text node

USE_CDATA

Output as a CDATA section

Throws:

XPathException - if an error occurs

processingInstruction

public void processingInstruction(java.lang.String target,
                                  java.lang.CharSequence data,
                                  Location locationId,
                                  int properties)

Processing Instruction

Specified by:

processingInstruction in interface Receiver

Overrides:

processingInstruction in class ProxyReceiver

Parameters:

target - The PI name. This must be a legal name (it will not be checked).

data - The data portion of the processing instruction

locationId - provides information such as line number and system ID.

properties - Additional information about the PI.

comment

public void comment(java.lang.CharSequence chars,
                    Location locationId,
                    int properties)
             throws XPathException

Output a comment

Specified by:

comment in interface Receiver

Overrides:

comment in class ProxyReceiver

Parameters:

chars - The content of the comment

locationId - provides information such as line number and system ID.

properties - Additional information about the comment.

Throws:

XPathException - if an error occurs

evaluateStatic

public Sequence evaluateStatic(java.lang.String expression,
                               Location locationId,
                               UseWhenStaticContext staticContext)
                        throws XPathException

Evaluate a static expression (to initialize a static variable)

Parameters:

expression - the expression to be evaluated

locationId - identifies the location of the expression in case error need to be reported

staticContext - the static context for evaluation of the expression

Returns:

the effective boolean value of the result of evaluating the expression

Throws:

XPathException - if evaluation of the expression fails