Package net.sf.saxon.instruct
Class ValueOf
- java.lang.Object
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- net.sf.saxon.expr.ComputedExpression
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- net.sf.saxon.instruct.Instruction
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- net.sf.saxon.instruct.SimpleNodeConstructor
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- net.sf.saxon.instruct.ValueOf
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- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,Container
,Expression
,TailCallReturner
,InstructionInfoProvider
public final class ValueOf extends SimpleNodeConstructor
An xsl:value-of element in the stylesheet.
The xsl:value-of element takes attributes:- a mandatory attribute select="expression". This must be a valid String expression
- an optional disable-output-escaping attribute, value "yes" or "no"
- an optional separator attribute. This is handled at compile-time: if the separator attribute is present, the select expression passed in here will be a call to the string-join() function.
- See Also:
- Serialized Form
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Field Summary
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Fields inherited from class net.sf.saxon.instruct.SimpleNodeConstructor
select
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Fields inherited from class net.sf.saxon.expr.ComputedExpression
locationId, staticProperties
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Fields inherited from interface net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
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Constructor Summary
Constructors Constructor Description ValueOf(Expression select, boolean disable, boolean noNodeIfEmpty)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole)
Check statically that the results of the expression are capable of constructing the content of a given schema type.int
computeCardinality()
Get the cardinality of the sequence returned by evaluating this instructionExpression
convertToStringJoin(StaticContext env)
Convert this value-of instruction to an expression that delivers the string-value of the resulting text node.void
display(int level, java.io.PrintStream out, Configuration config)
Display this instruction as an expression, for diagnosticsItem
evaluateItem(XPathContext context)
Evaluate this expression, returning the resulting text node to the callerint
getInstructionNameCode()
Get the name of this instruction for diagnostic and tracing purposesItemType
getItemType(TypeHierarchy th)
Get the item type of the items returned by evaluating this instructionboolean
isNumberingInstruction()
Determine whether this is really an xsl:number instructionvoid
localTypeCheck(StaticContext env, ItemType contextItemType)
TailCall
processLeavingTail(XPathContext context)
Process this instruction, sending the resulting text node to the current output destinationprotected void
promoteInst(PromotionOffer offer)
Offer promotion for subexpressions.void
setIsNumberingInstruction()
Indicate that this is really an xsl:nunber instruction-
Methods inherited from class net.sf.saxon.instruct.SimpleNodeConstructor
checkContent, computeSpecialProperties, createsNewNodes, evaluateNameCode, expandChildren, getSelect, iterate, iterateSubExpressions, optimize, replaceSubExpression, setSelect, simplify, typeCheck
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Methods inherited from class net.sf.saxon.instruct.Instruction
appendItem, assembleParams, assembleTunnelParams, dynamicError, evaluateAsString, getImplementationMethod, getInstructionInfo, getSourceLocator, isXSLT, process, promote
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Methods inherited from class net.sf.saxon.expr.ComputedExpression
adoptChildExpression, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError
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Constructor Detail
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ValueOf
public ValueOf(Expression select, boolean disable, boolean noNodeIfEmpty)
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Method Detail
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setIsNumberingInstruction
public void setIsNumberingInstruction()
Indicate that this is really an xsl:nunber instruction
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isNumberingInstruction
public boolean isNumberingInstruction()
Determine whether this is really an xsl:number instruction
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getInstructionNameCode
public int getInstructionNameCode()
Get the name of this instruction for diagnostic and tracing purposes- Overrides:
getInstructionNameCode
in classInstruction
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promoteInst
protected void promoteInst(PromotionOffer offer) throws XPathException
Offer promotion for subexpressions. The offer will be accepted if the subexpression is not dependent on the factors (e.g. the context item) identified in the PromotionOffer. By default the offer is not accepted - this is appropriate in the case of simple expressions such as constant values and variable references where promotion would give no performance advantage. This method is always called at compile time.- Overrides:
promoteInst
in classSimpleNodeConstructor
- Parameters:
offer
- details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression- Throws:
XPathException
- if any error is detected
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getItemType
public ItemType getItemType(TypeHierarchy th)
Description copied from class:Instruction
Get the item type of the items returned by evaluating this instruction- Specified by:
getItemType
in interfaceExpression
- Overrides:
getItemType
in classInstruction
- Returns:
- the static item type of the instruction
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computeCardinality
public int computeCardinality()
Description copied from class:Instruction
Get the cardinality of the sequence returned by evaluating this instruction- Overrides:
computeCardinality
in classInstruction
- Returns:
- the static cardinality
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localTypeCheck
public void localTypeCheck(StaticContext env, ItemType contextItemType)
- Specified by:
localTypeCheck
in classSimpleNodeConstructor
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checkPermittedContents
public void checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole) throws XPathException
Check statically that the results of the expression are capable of constructing the content of a given schema type.- Specified by:
checkPermittedContents
in interfaceExpression
- Overrides:
checkPermittedContents
in classComputedExpression
- Parameters:
parentType
- The schema typeenv
- the static contextwhole
-- Throws:
XPathException
- if the expression doesn't match the required content type
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convertToStringJoin
public Expression convertToStringJoin(StaticContext env)
Convert this value-of instruction to an expression that delivers the string-value of the resulting text node. This will often be a call on the string-join function.
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processLeavingTail
public TailCall processLeavingTail(XPathContext context) throws XPathException
Process this instruction, sending the resulting text node to the current output destination- Specified by:
processLeavingTail
in interfaceTailCallReturner
- Specified by:
processLeavingTail
in classInstruction
- Parameters:
context
-- Returns:
- Always returns null
- Throws:
XPathException
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evaluateItem
public Item evaluateItem(XPathContext context) throws XPathException
Evaluate this expression, returning the resulting text node to the caller- Specified by:
evaluateItem
in interfaceExpression
- Overrides:
evaluateItem
in classSimpleNodeConstructor
- Parameters:
context
-- Returns:
- the parentless text node that results from evaluating this instruction, or null to represent an empty sequence
- Throws:
XPathException
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display
public void display(int level, java.io.PrintStream out, Configuration config)
Display this instruction as an expression, for diagnostics- Specified by:
display
in interfaceExpression
- Overrides:
display
in classSimpleNodeConstructor
- Parameters:
level
- indentation level for this expressionout
- Output destination
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