Class CallTemplate
- java.lang.Object
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- net.sf.saxon.expr.Expression
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- net.sf.saxon.instruct.Instruction
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- net.sf.saxon.instruct.CallTemplate
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- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,LocationProvider
,SaxonLocator
,EvaluableItem
,SequenceIterable
,TailCallReturner
,InstructionInfo
,org.xml.sax.Locator
public class CallTemplate extends Instruction
Instruction representing an xsl:call-template element in the stylesheet.- See Also:
- Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
CallTemplate.CallTemplatePackage
A CallTemplatePackage is an object that encapsulates the name of a template to be called, the parameters to be supplied, and the execution context.
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Field Summary
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Fields inherited from class net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
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Constructor Summary
Constructors Constructor Description CallTemplate(Template template, boolean useTailRecursion, Expression calledTemplateExpression, NamespaceResolver nsContext)
Construct a CallTemplate instruction.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
computeCardinality()
Get the cardinality of the sequence returned by evaluating this instructionExpression
copy()
Copy an expression.boolean
createsNewNodes()
Determine whether this instruction creates new nodes.void
explain(ExpressionPresenter out)
Diagnostic print of expression structure.int
getInstructionNameCode()
Return the name of this instruction.int
getIntrinsicDependencies()
Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions.ItemType
getItemType(TypeHierarchy th)
Get the item type of the items returned by evaluating this instructionStructuredQName
getObjectName()
Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc.Template
getTargetTemplate(XPathContext context)
Get the template, in the case where it is specified dynamically.java.util.Iterator
iterateSubExpressions()
Get all the XPath expressions associated with this instruction (in XSLT terms, the expression present on attributes of the instruction, as distinct from the child instructions in a sequence construction)Expression
optimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.void
process(XPathContext context)
Process this instruction, without leaving any tail calls.TailCall
processLeavingTail(XPathContext context)
Process this instruction.protected void
promoteInst(PromotionOffer offer)
Handle promotion offers, that is, non-local tree rewrites.boolean
replaceSubExpression(Expression original, Expression replacement)
Replace one subexpression by a replacement subexpressionvoid
setActualParameters(WithParam[] actualParams, WithParam[] tunnelParams)
Set the actual parameters on the callExpression
simplify(ExpressionVisitor visitor)
Simplify an expression.Expression
typeCheck(ExpressionVisitor visitor, ItemType contextItemType)
Perform type checking of an expression and its subexpressions.-
Methods inherited from class net.sf.saxon.instruct.Instruction
assembleParams, assembleTunnelParams, computeSpecialProperties, dynamicError, evaluateAsString, evaluateItem, getConstructType, getImplementationMethod, getSourceLocator, isXSLT, iterate, promote
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Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, findParentOf, getCardinality, getColumnNumber, getColumnNumber, getContainer, getDependencies, getExecutable, getHostLanguage, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterateEvents, markTailFunctionCalls, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toString, typeError
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Constructor Detail
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CallTemplate
public CallTemplate(Template template, boolean useTailRecursion, Expression calledTemplateExpression, NamespaceResolver nsContext)
Construct a CallTemplate instruction.- Parameters:
template
- the Template object identifying the template to be called, in the normal case where this is known staticallyuseTailRecursion
- true if the call is potentially tail recursivecalledTemplateExpression
- expression to calculate the name of the template to be called at run-time, this supports the saxon:allow-avt optionnsContext
- the static namespace context of the instruction, needed only in the case where the name of the called template is to be calculated dynamically
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Method Detail
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setActualParameters
public void setActualParameters(WithParam[] actualParams, WithParam[] tunnelParams)
Set the actual parameters on the call- Parameters:
actualParams
- the parameters that are not tunnel parameterstunnelParams
- the tunnel parameters
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getInstructionNameCode
public int getInstructionNameCode()
Return the name of this instruction.- Overrides:
getInstructionNameCode
in classInstruction
- Returns:
- a code identifying the instruction: typically but not always the fingerprint of a name in the XSLT namespace
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simplify
public Expression simplify(ExpressionVisitor visitor) throws XPathException
Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression).- Specified by:
simplify
in classInstruction
- Parameters:
visitor
- an expression visitor- Returns:
- the simplified expression
- Throws:
XPathException
- if an error is discovered during expression rewriting
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typeCheck
public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException
Description copied from class:Expression
Perform type checking of an expression and its subexpressions. This is the second phase of static optimization.This checks statically that the operands of the expression have the correct type; if necessary it generates code to do run-time type checking or type conversion. A static type error is reported only if execution cannot possibly succeed, that is, if a run-time type error is inevitable. The call may return a modified form of the expression.
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable. However, the types of such functions and variables may not be accurately known if they have not been explicitly declared.
If the implementation returns a value other than "this", then it is required to ensure that the parent pointer and location information in the returned expression have been set up correctly. It should not rely on the caller to do this, although for historical reasons many callers do so.
- Overrides:
typeCheck
in classExpression
- Parameters:
visitor
- an expression visitorcontextItemType
- the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set toType.ITEM_TYPE
- Returns:
- the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
- Throws:
XPathException
- if an error is discovered during this phase (typically a type error)
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optimize
public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException
Description copied from class:Expression
Perform optimisation of an expression and its subexpressions. This is the third and final phase of static optimization.This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.
- Overrides:
optimize
in classExpression
- Parameters:
visitor
- an expression visitorcontextItemType
- the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set toType.ITEM_TYPE
- Returns:
- the original expression, rewritten if appropriate to optimize execution
- Throws:
XPathException
- if an error is discovered during this phase (typically a type error)
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computeCardinality
public int computeCardinality()
Get the cardinality of the sequence returned by evaluating this instruction- Overrides:
computeCardinality
in classInstruction
- Returns:
- the static cardinality
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getItemType
public ItemType getItemType(TypeHierarchy th)
Get the item type of the items returned by evaluating this instruction- Overrides:
getItemType
in classInstruction
- Parameters:
th
- the type hierarchy cache- Returns:
- the static item type of the instruction
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copy
public Expression copy()
Copy an expression. This makes a deep copy.- Specified by:
copy
in classExpression
- Returns:
- the copy of the original expression
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getIntrinsicDependencies
public int getIntrinsicDependencies()
Description copied from class:Expression
Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. For example, position() has an intrinsic dependency on the context position, while (position()+1) does not. The default implementation of the method returns 0, indicating "no dependencies".- Overrides:
getIntrinsicDependencies
in classExpression
- Returns:
- a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty
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createsNewNodes
public final boolean createsNewNodes()
Determine whether this instruction creates new nodes. This implementation currently returns true unconditionally.- Overrides:
createsNewNodes
in classInstruction
- Returns:
- true if the instruction creates new nodes (or if it can't be proved that it doesn't)
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iterateSubExpressions
public java.util.Iterator iterateSubExpressions()
Get all the XPath expressions associated with this instruction (in XSLT terms, the expression present on attributes of the instruction, as distinct from the child instructions in a sequence construction)- Overrides:
iterateSubExpressions
in classExpression
- Returns:
- an iterator containing the sub-expressions of this expression
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replaceSubExpression
public boolean replaceSubExpression(Expression original, Expression replacement)
Replace one subexpression by a replacement subexpression- Overrides:
replaceSubExpression
in classExpression
- Parameters:
original
- the original subexpressionreplacement
- the replacement subexpression- Returns:
- true if the original subexpression is found
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promoteInst
protected void promoteInst(PromotionOffer offer) throws XPathException
Handle promotion offers, that is, non-local tree rewrites.- Overrides:
promoteInst
in classInstruction
- Parameters:
offer
- The type of rewrite being offered- Throws:
XPathException
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process
public void process(XPathContext context) throws XPathException
Process this instruction, without leaving any tail calls.- Overrides:
process
in classInstruction
- Parameters:
context
- the dynamic context for this transformation- Throws:
XPathException
- if a dynamic error occurs
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processLeavingTail
public TailCall processLeavingTail(XPathContext context) throws XPathException
Process this instruction. If the called template contains a tail call (which may be an xsl:call-template of xsl:apply-templates instruction) then the tail call will not actually be evaluated, but will be returned in a TailCall object for the caller to execute.- Specified by:
processLeavingTail
in interfaceTailCallReturner
- Specified by:
processLeavingTail
in classInstruction
- Parameters:
context
- the dynamic context for this transformation- Returns:
- an object containing information about the tail call to be executed by the caller. Returns null if there is no tail call.
- Throws:
XPathException
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getTargetTemplate
public Template getTargetTemplate(XPathContext context) throws XPathException
Get the template, in the case where it is specified dynamically.- Parameters:
context
- The dynamic context of the transformation- Returns:
- The template to be called
- Throws:
XPathException
- if a dynamic error occurs: specifically, if the template name is computed at run-time (Saxon extension) and the name is invalid or does not reference a known template
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getObjectName
public StructuredQName getObjectName()
Description copied from interface:InstructionInfo
Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc. This is used only where the name is known statically.- Specified by:
getObjectName
in interfaceInstructionInfo
- Overrides:
getObjectName
in classExpression
- Returns:
- the QName of the object declared or manipulated by this instruction or expression
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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 classExpression
- Parameters:
out
- the expression presenter used to display the structure
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