ValueOf

java.lang.Object
- net.sf.saxon.expr.Expression
- - net.sf.saxon.instruct.Instruction
  - - net.sf.saxon.instruct.SimpleNodeConstructor
    - - net.sf.saxon.instruct.ValueOf

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfo, org.xml.sax.Locator
```
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

Field Summary
- Fields inherited from class net.sf.saxon.expr.Expression
  EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
- Fields inherited from class net.sf.saxon.instruct.SimpleNodeConstructor
  select

Constructor Summary

Constructors
Constructor Description

ValueOf(Expression select, boolean disable, boolean noNodeIfEmpty)
Create a new ValueOf expression

Constructors
Constructor	Description
`ValueOf(Expression select, boolean disable, boolean noNodeIfEmpty)`	Create a new ValueOf expression

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 instruction
`Expression`	`convertToStringJoin(StaticContext env)`	Convert this value-of instruction to an expression that delivers the string-value of the resulting text node.
`Expression`	`copy()`	Copy an expression.
`Item`	`evaluateItem(XPathContext context)`	Evaluate this expression, returning the resulting text node to the caller
`void`	`explain(ExpressionPresenter out)`	Diagnostic print of expression structure.
`int`	`getInstructionNameCode()`	Get the name of this instruction for diagnostic and tracing purposes
`ItemType`	`getItemType(TypeHierarchy th)`	Get the item type of the items returned by evaluating this instruction
`int`	`getOptions()`	Test for any special options such as disable-output-escaping
`boolean`	`isDisableOutputEscaping()`	Test whether disable-output-escaping was requested
`boolean`	`isNumberingInstruction()`	Determine whether this is really an xsl:number instruction
`void`	`localTypeCheck(ExpressionVisitor visitor, ItemType contextItemType)`	Method to perform type-checking specific to the kind of instruction
`TailCall`	`processLeavingTail(XPathContext context)`	Process this instruction, sending the resulting text node to the current output destination
`protected 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.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, findParentOf, getCardinality, getColumnNumber, getColumnNumber, getContainer, getDependencies, getExecutable, getHostLanguage, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterateEvents, markTailFunctionCalls, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toString, typeError

Methods inherited from class net.sf.saxon.instruct.Instruction
assembleParams, assembleTunnelParams, dynamicError, evaluateAsString, getConstructType, getImplementationMethod, getSourceLocator, isXSLT, process, promote

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from class net.sf.saxon.instruct.SimpleNodeConstructor
checkContent, computeSpecialProperties, createsNewNodes, evaluateNameCode, expandChildren, getSelect, iterate, iterateSubExpressions, optimize, replaceSubExpression, setSelect, simplify, typeCheck

Methods inherited from interface javax.xml.transform.SourceLocator
getColumnNumber, getLineNumber, getPublicId, getSystemId

- Constructor Detail
  - ValueOf
```
public ValueOf(Expression select,
               boolean disable,
               boolean noNodeIfEmpty)
```
    Create a new ValueOf expression
    
    Parameters:
    
    select - the select expression
    
    disable - true if disable-output-escaping is in force
    
    noNodeIfEmpty - true if the instruction is to return () if the select expression is (), false if it is to return an empty text node
- Method Detail
  - setIsNumberingInstruction
```
public void setIsNumberingInstruction()
```
    Indicate that this is really an xsl:nunber instruction
  - isNumberingInstruction
```
public boolean isNumberingInstruction()
```
    Determine whether this is really an xsl:number instruction
    
    Returns:
    
    true if this derives from xsl:number
  - getInstructionNameCode
```
public int getInstructionNameCode()
```
    Get the name of this instruction for diagnostic and tracing purposes
    
    Overrides:
    
    getInstructionNameCode in class Instruction
    
    Returns:
    
    the namecode of the instruction name
  - 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 class SimpleNodeConstructor
    
    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
  - getOptions
```
public int getOptions()
```
    Test for any special options such as disable-output-escaping
    
    Returns:
    
    any special options
  - isDisableOutputEscaping
```
public boolean isDisableOutputEscaping()
```
    Test whether disable-output-escaping was requested
    
    Returns:
    
    true if disable-output-escaping was requested
  - getItemType
```
public ItemType getItemType(TypeHierarchy th)
```
    Description copied from class: Instruction
    
    Get the item type of the items returned by evaluating this instruction
    
    Overrides:
    
    getItemType in class Instruction
    
    Parameters:
    
    th - the type hierarchy cache
    
    Returns:
    
    the static item type of the instruction
  - computeCardinality
```
public int computeCardinality()
```
    Description copied from class: SimpleNodeConstructor
    
    Get the cardinality of the sequence returned by evaluating this instruction
    
    Overrides:
    
    computeCardinality in class SimpleNodeConstructor
    
    Returns:
    
    the static cardinality
  - localTypeCheck
```
public void localTypeCheck(ExpressionVisitor visitor,
                           ItemType contextItemType)
```
    Description copied from class: SimpleNodeConstructor
    
    Method to perform type-checking specific to the kind of instruction
    
    Specified by:
    
    localTypeCheck in class SimpleNodeConstructor
    
    Parameters:
    
    visitor - an expression visitor
    
    contextItemType - the static type of the context item
  - copy
```
public Expression copy()
```
    Copy an expression. This makes a deep copy.
    
    Specified by:
    
    copy in class Expression
    
    Returns:
    
    the copy of the original expression
  - 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.
    
    Overrides:
    
    checkPermittedContents in class Expression
    
    Parameters:
    
    parentType - The schema type
    
    env - the static context
    
    whole - true if this expression is to account for the whole value of the type
    
    Throws:
    
    XPathException - if the expression doesn't match the required content type
  - 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.
    
    Parameters:
    
    env - the static evaluation context
    
    Returns:
    
    the converted expression
  - 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 interface TailCallReturner
    
    Specified by:
    
    processLeavingTail in class Instruction
    
    Parameters:
    
    context - the dynamic evaluation context
    
    Returns:
    
    Always returns null
    
    Throws:
    
    XPathException
  - evaluateItem
```
public Item evaluateItem(XPathContext context)
                  throws XPathException
```
    Evaluate this expression, returning the resulting text node to the caller
    
    Specified by:
    
    evaluateItem in interface EvaluableItem
    
    Overrides:
    
    evaluateItem in class SimpleNodeConstructor
    
    Parameters:
    
    context - the dynamic evaluation context
    
    Returns:
    
    the parentless text node that results from evaluating this instruction, or null to represent an empty sequence
    
    Throws:
    
    XPathException
  - explain
```
public void explain(ExpressionPresenter out)
```
    Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
    
    Specified by:
    
    explain in class Expression
    
    Parameters:
    
    out - the expression presenter used to display the structure

Class ValueOf

Field Summary

Fields inherited from class net.sf.saxon.expr.Expression

Fields inherited from class net.sf.saxon.instruct.SimpleNodeConstructor

Constructor Summary

Method Summary

Methods inherited from class net.sf.saxon.expr.Expression

Methods inherited from class net.sf.saxon.instruct.Instruction

Methods inherited from class java.lang.Object

Methods inherited from class net.sf.saxon.instruct.SimpleNodeConstructor

Methods inherited from interface javax.xml.transform.SourceLocator

Constructor Detail

ValueOf

Method Detail

setIsNumberingInstruction

isNumberingInstruction

getInstructionNameCode

promoteInst

getOptions

isDisableOutputEscaping

getItemType

computeCardinality

localTypeCheck

copy

checkPermittedContents

convertToStringJoin

processLeavingTail

evaluateItem

explain