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

Method Summary

Modifier and Type	Method and Description
void	attribute(NodeName attName, SimpleType typeCode, java.lang.CharSequence value, Location locationId, int properties) Notify an attribute.
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
XPathException	createXPathException(java.lang.String message, java.lang.String errorCode, Location location)
void	endElement() End of element
Sequence<?>	evaluateStatic(java.lang.String expression, Location locationId, UseWhenStaticContext staticContext) Evaluate a static expression (to initialize a static variable)
boolean	evaluateUseWhen(java.lang.String expression, AttributeLocation location, java.lang.String baseUri) Evaluate a use-when attribute
void	namespace(NamespaceBindingSet namespaceBindings, int properties) Notify a namespace.
void	open() Start of document
void	processingInstruction(java.lang.String target, java.lang.CharSequence data, Location locationId, int properties) Processing Instruction
void	setStartTagBuffer(StartTagBuffer startTag) Set the start tag buffer
void	startContent() Notify the start of the content, that is, the completion of all attributes and namespaces.
void	startElement(NodeName elemName, SchemaType typeCode, 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

setStartTagBuffer

public void setStartTagBuffer(StartTagBuffer startTag)

Set the start tag buffer

Parameters:

startTag - a preceding filter on the pipeline that buffers the attributes of a start tag

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 typeCode,
                         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.

typeCode - integer code identifying the element's type within the name pool.

location - location where the event originated

properties - bit-significant properties of the element node

Throws:

XPathException - if an error occurs

createXPathException

public XPathException createXPathException(java.lang.String message,
                                           java.lang.String errorCode,
                                           Location location)

namespace

public void namespace(NamespaceBindingSet namespaceBindings,
                      int properties)
               throws XPathException

Notify a namespace. Namespaces are notified after the startElement event, and before any children for the element. The namespaces that are reported are only required to include those that are different from the parent element; however, duplicates may be reported. A namespace must not conflict with any namespaces already used for element or attribute names.

Specified by:

namespace in interface Receiver

Overrides:

namespace in class ProxyReceiver

Parameters:

namespaceBindings - the namespace to be notified

properties - any special properties to be passed on this call

Throws:

IllegalStateException: - attempt to output a namespace when there is no open element start tag

XPathException - if an error occurs

attribute

public void attribute(NodeName attName,
                      SimpleType typeCode,
                      java.lang.CharSequence value,
                      Location locationId,
                      int properties)
               throws XPathException

Notify an attribute. Attributes are notified after the startElement event, and before any children. Namespaces and attributes may be intermingled.

Specified by:

attribute in interface Receiver

Overrides:

attribute in class ProxyReceiver

Parameters:

attName - The name of the attribute

typeCode - The type of the attribute

locationId - the location of the node in the source, or of the instruction that created it

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

DISABLE_ESCAPING

Disable escaping for this attribute

NO_SPECIAL_CHARACTERS

Attribute value contains no special characters

value - the string value of the attribute

Throws:

IllegalStateException: - attempt to output an attribute when there is no open element start tag

XPathException - if an error occurs

startContent

public void startContent()
                  throws XPathException

Notify the start of the content, that is, the completion of all attributes and namespaces. Note that the initial receiver of output from XSLT instructions will not receive this event, it has to detect it itself. Note that this event is reported for every element even if it has no attributes, no namespaces, and no content.

Specified by:

startContent in interface Receiver

Overrides:

startContent in class ProxyReceiver

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

evaluateUseWhen

public boolean evaluateUseWhen(java.lang.String expression,
                               AttributeLocation location,
                               java.lang.String baseUri)
                        throws XPathException

Evaluate a use-when attribute

Parameters:

expression - the expression to be evaluated

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

baseUri - the base URI of the element containing the expression

Returns:

the effective boolean value of the result of evaluating the expression

Throws:

XPathException - if evaluation of the expression fails

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