net.sf.saxon.instruct
Class ApplyTemplates

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.instruct.Instruction
          net.sf.saxon.instruct.ApplyTemplates

All Implemented Interfaces:

Serializable, SourceLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfoProvider

public class ApplyTemplates
extends Instruction

An instruction representing an xsl:apply-templates element in the stylesheet

See Also:

Serialized Form

Field Summary

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

ApplyTemplates(Expression select, boolean useCurrentMode, boolean useTailRecursion, Mode mode, boolean backwardsCompatible, boolean implicitSelect)
Construct an apply-templates instructino

Method Summary

static TailCall	applyTemplates(SequenceIterator iterator, Mode mode, ParameterSet parameters, ParameterSet tunnelParameters, XPathContextMajor context, boolean backwardsCompatible, int locationId) Process selected nodes using the handlers registered for a particular mode.
Expression	copy() Copy an expression.
boolean	createsNewNodes() Determine whether this instruction creates new nodes.
static void	defaultAction(NodeInfo node, ParameterSet parameters, ParameterSet tunnelParams, XPathContext context, boolean backwardsCompatible, int locationId) Perform the built-in template action for a given node.
void	explain(ExpressionPresenter out) Diagnostic print of expression structure.
InstructionInfo	getInstructionInfo() Set additional trace properties appropriate to the kind of instruction.
int	getInstructionNameCode() Get the name of this instruction for diagnostic and tracing purposes
Expression	getSelectExpression() Get the select expression
boolean	hasLoopingSubexpression(Expression child) Given an expression that is an immediate child of this expression, test whether the evaluation of the parent expression causes the child expression to be evaluated repeatedly
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 the instruction, without returning any tail calls
TailCall	processLeavingTail(XPathContext context) ProcessLeavingTail: called to do the real work of this instruction.
boolean	replaceSubExpression(Expression original, Expression replacement) Replace one subexpression by a replacement subexpression
void	setActualParameters(WithParam[] actualParams, WithParam[] tunnelParams) Set the actual parameters on the call
Expression	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

computeCardinality, computeSpecialProperties, evaluateAsString, evaluateItem, getImplementationMethod, getItemType, getSourceLocator, isXSLT, iterate, promote

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

addToPathMap, adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, effectiveBooleanValue, explain, findParentOf, getCardinality, getColumnNumber, getContainer, getDependencies, getExecutable, getHostLanguage, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, implementsStaticTypeCheck, iterateEvents, markTailFunctionCalls, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface javax.xml.transform.SourceLocator

getColumnNumber, getLineNumber, getPublicId, getSystemId

Constructor Detail

ApplyTemplates

public ApplyTemplates(Expression select,
                      boolean useCurrentMode,
                      boolean useTailRecursion,
                      Mode mode,
                      boolean backwardsCompatible,
                      boolean implicitSelect)

Construct an apply-templates instructino

Parameters:

select - the select expression

useCurrentMode - true if mode="#current" was specified

useTailRecursion - true if this instruction is the last in its template

mode - the mode specified on apply-templates

backwardsCompatible - true if XSLT backwards compatibility is enabled

implicitSelect - true if the select attribute was defaulted

Method Detail

setActualParameters

public void setActualParameters(WithParam[] actualParams,
                                WithParam[] tunnelParams)

Set the actual parameters on the call

Parameters:

actualParams - represents the contained xsl:with-param elements having tunnel="no" (the default)

tunnelParams - represents the contained xsl:with-param elements having tunnel="yes"

getInstructionNameCode

public int getInstructionNameCode()

Get the name of this instruction for diagnostic and tracing purposes

Overrides:

getInstructionNameCode in class Instruction

Returns:

a code identifying the instruction: typically but not always the fingerprint of a name in the XSLT namespace

getInstructionInfo

public InstructionInfo getInstructionInfo()

Set additional trace properties appropriate to the kind of instruction. This implementation adds the mode attribute

Specified by:

getInstructionInfo in interface InstructionInfoProvider

Overrides:

getInstructionInfo in class Instruction

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 class Instruction

Parameters:

visitor - the expression visitor

Returns:

the simplified expression

Throws:

XPathException - if an error is discovered during expression rewriting

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 class Expression

Parameters:

visitor - an expression visitor

contextItemType - 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 to Type.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)

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 class Expression

Parameters:

visitor - an expression visitor

contextItemType - 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 to Type.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)

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

createsNewNodes

public final boolean createsNewNodes()

Determine whether this instruction creates new nodes. This implementation returns true (which is almost invariably the case, so it's not worth doing any further analysis to find out more precisely).

Overrides:

createsNewNodes in class Instruction

Returns:

true if the instruction creates new nodes (or if it can't be proved that it doesn't)

process

public void process(XPathContext context)
             throws XPathException

Description copied from class: Instruction

Process the instruction, without returning any tail calls

Overrides:

process in class Instruction

Parameters:

context - The dynamic context, giving access to the current node, the current variables, etc.

Throws:

XPathException

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws XPathException

Description copied from class: Instruction

ProcessLeavingTail: called to do the real work of this instruction. This method must be implemented in each subclass. The results of the instruction are written to the current Receiver, which can be obtained via the Controller.

Specified by:

processLeavingTail in interface TailCallReturner

Specified by:

processLeavingTail in class Instruction

Parameters:

context - The dynamic context of the transformation, giving access to the current node, the current variables, etc.

Returns:

null if the instruction has completed execution; or a TailCall indicating a function call or template call that is delegated to the caller, to be made after the stack has been unwound so as to save stack space.

Throws:

XPathException

applyTemplates

public static TailCall applyTemplates(SequenceIterator iterator,
                                      Mode mode,
                                      ParameterSet parameters,
                                      ParameterSet tunnelParameters,
                                      XPathContextMajor context,
                                      boolean backwardsCompatible,
                                      int locationId)
                               throws XPathException

Process selected nodes using the handlers registered for a particular mode.

Parameters:

iterator - an Iterator over the nodes to be processed, in the correct (sorted) order

mode - Identifies the processing mode. It should match the mode defined when the element handler was registered using setHandler with a mode parameter. Set this parameter to null to invoke the default mode.

parameters - A ParameterSet containing the parameters to the handler/template being invoked. Specify null if there are no parameters.

tunnelParameters - A ParameterSet containing the parameters to the handler/template being invoked. Specify null if there are no parameters.

context - A newly-created context object (this must be freshly created by the caller, as it will be modified by this method)

backwardsCompatible - true if running in backwards compatibility mode

locationId - location of this apply-templates instruction in the stylesheet

Returns:

a TailCall returned by the last template to be invoked, or null, indicating that there are no outstanding tail calls.

Throws:

XPathException - if any dynamic error occurs

defaultAction

public static void defaultAction(NodeInfo node,
                                 ParameterSet parameters,
                                 ParameterSet tunnelParams,
                                 XPathContext context,
                                 boolean backwardsCompatible,
                                 int locationId)
                          throws XPathException

Perform the built-in template action for a given node.

Parameters:

node - the node to be processed

parameters - the parameters supplied to apply-templates

tunnelParams - the tunnel parameters to be passed through

context - the dynamic evaluation context

backwardsCompatible - true if in 1.0 mode (currently makes no difference)

locationId - location of the instruction (apply-templates, apply-imports etc) that caused the built-in template to be invoked

Throws:

XPathException - if any dynamic error occurs

iterateSubExpressions

public 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 class Expression

Returns:

an iterator containing the sub-expressions of this expression

hasLoopingSubexpression

public boolean hasLoopingSubexpression(Expression child)

Given an expression that is an immediate child of this expression, test whether the evaluation of the parent expression causes the child expression to be evaluated repeatedly

Overrides:

hasLoopingSubexpression in class Expression

Parameters:

child - the immediate subexpression

Returns:

true if the child expression is evaluated repeatedly

replaceSubExpression

public boolean replaceSubExpression(Expression original,
                                    Expression replacement)

Replace one subexpression by a replacement subexpression

Overrides:

replaceSubExpression in class Expression

Parameters:

original - the original subexpression

replacement - the replacement subexpression

Returns:

true if the original subexpression is found

getSelectExpression

public Expression getSelectExpression()

Get the select expression

Returns:

the select expression

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 - output destination