net.sf.saxon.instruct

Class ElementCreator

java.lang.Object

net.sf.saxon.expr.ComputedExpression

net.sf.saxon.instruct.Instruction

net.sf.saxon.instruct.ParentNodeConstructor

net.sf.saxon.instruct.ElementCreator

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, Container, Expression, TailCallReturner, InstructionInfoProvider

Direct Known Subclasses:

ComputedElement, Copy, FixedElement

public abstract class ElementCreator
extends ParentNodeConstructor

An instruction that creates an element node. There are two subtypes, FixedElement for use where the name is known statically, and Element where it is computed dynamically. To allow use in both XSLT and XQuery, the class acts both as an Instruction and as an Expression.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	inheritNamespaces The inheritNamespaces flag indicates that the namespace nodes on the element created by this instruction are to be inherited (copied) on the children of this element.
protected boolean	validating The validating flag is set if the type attribute is set or if validation is set to anything other than preserve.

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

content, validation

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

locationId, staticProperties

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

Constructors

Constructor and Description
ElementCreator()

Method Summary

Modifier and Type	Method and Description
protected void	checkContentForAttributes(StaticContext env) Check statically whether the content of the element creates attributes or namespaces after creating any child nodes
int	computeSpecialProperties() Get the static properties of this expression (other than its type).
Item	evaluateItem(XPathContext context) Evaluate the constructor, returning the constructed element node.
int[]	getActiveNamespaces() Callback to get a list of the intrinsic namespaces that need to be generated for the element.
int	getImplementationMethod() An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
ItemType	getItemType(TypeHierarchy th) Get the item type of the value returned by this instruction
abstract int	getNameCode(XPathContext context)
abstract java.lang.String	getNewBaseURI(XPathContext context) Get the base URI for the element being constructed
int	getValidationMode() Get the validation mode for the constructed element
boolean	isInheritNamespaces() Determine whether the inherit namespaces flag is set
boolean	isValidating() Determine whether this elementCreator performs validation
protected abstract void	outputNamespaceNodes(XPathContext context, Receiver receiver) Callback to output namespace nodes for the new element.
TailCall	processLeavingTail(XPathContext context) Evaluate the instruction to produce a new element node.
void	setValidationMode(int mode) Set the validation mode for the new element
void	suppressValidation(int validationMode) Suppress validation on contained element constructors, on the grounds that the parent element is already performing validation.

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

createsNewNodes, getBaseURI, getCardinality, getContentExpression, getSchemaType, getValidationAction, isLazyConstruction, isNamespaceSensitive, iterateSubExpressions, optimize, promoteInst, replaceSubExpression, setBaseURI, setContentExpression, setLazyConstruction, setSchemaType, simplify, typeCheck, verifyLazyConstruction

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

appendItem, assembleParams, assembleTunnelParams, computeCardinality, dynamicError, evaluateAsString, getInstructionInfo, getInstructionNameCode, getSourceLocator, isXSLT, iterate, process, promote

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

adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, typeError

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface javax.xml.transform.SourceLocator

getColumnNumber, getLineNumber, getPublicId, getSystemId

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

display

Field Detail

inheritNamespaces

protected boolean inheritNamespaces

The inheritNamespaces flag indicates that the namespace nodes on the element created by this instruction are to be inherited (copied) on the children of this element. That is, if this flag is false, the child elements must carry a namespace undeclaration for all the namespaces on the parent, unless they are redeclared in some way.

validating

protected boolean validating

The validating flag is set if the type attribute is set or if validation is set to anything other than preserve. This is used simply to fast-path the case where no validation is required.

Constructor Detail

ElementCreator

public ElementCreator()

Method Detail

getItemType

public ItemType getItemType(TypeHierarchy th)

Get the item type of the value returned by this instruction

Specified by:

getItemType in interface Expression

Overrides:

getItemType in class Instruction

Parameters:

th -

Returns:

the item type

isValidating

public boolean isValidating()

Determine whether this elementCreator performs validation

isInheritNamespaces

public boolean isInheritNamespaces()

Determine whether the inherit namespaces flag is set

computeSpecialProperties

public int computeSpecialProperties()

Get the static properties of this expression (other than its type). The result is bit-signficant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.

Overrides:

computeSpecialProperties in class Instruction

Returns:

a set of flags indicating static properties of this expression

setValidationMode

public void setValidationMode(int mode)

Set the validation mode for the new element

getValidationMode

public int getValidationMode()

Get the validation mode for the constructed element

suppressValidation

public void suppressValidation(int validationMode)

Suppress validation on contained element constructors, on the grounds that the parent element is already performing validation. The default implementation does nothing.

Overrides:

suppressValidation in class ComputedExpression

checkContentForAttributes

protected void checkContentForAttributes(StaticContext env)
                                  throws XPathException

Check statically whether the content of the element creates attributes or namespaces after creating any child nodes

Specified by:

checkContentForAttributes in class ParentNodeConstructor

Parameters:

env - the static context

Throws:

XPathException

getNameCode

public abstract int getNameCode(XPathContext context)
                         throws XPathException

Throws:

XPathException

getNewBaseURI

public abstract java.lang.String getNewBaseURI(XPathContext context)

Get the base URI for the element being constructed

Parameters:

context -

outputNamespaceNodes

protected abstract void outputNamespaceNodes(XPathContext context,
                                             Receiver receiver)
                                      throws XPathException

Callback to output namespace nodes for the new element.

Parameters:

context - The execution context

receiver - the Receiver where the namespace nodes are to be written

Throws:

XPathException

getActiveNamespaces

public int[] getActiveNamespaces()
                          throws XPathException

Callback to get a list of the intrinsic namespaces that need to be generated for the element. The result is an array of namespace codes, the codes either occupy the whole array or are terminated by a -1 entry. A result of null is equivalent to a zero-length array.

Throws:

XPathException

getImplementationMethod

public int getImplementationMethod()

An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is prefered. For instructions this is the process() method.

Specified by:

getImplementationMethod in interface Expression

Overrides:

getImplementationMethod in class Instruction

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws XPathException

Evaluate the instruction to produce a new element node. This method is typically used when there is a parent element or document in a result tree, to which the new element is added.

Specified by:

processLeavingTail in interface TailCallReturner

Specified by:

processLeavingTail in class Instruction

Parameters:

context -

Returns:

null (this instruction never returns a tail call)

Throws:

XPathException

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException

Evaluate the constructor, returning the constructed element node. If lazy construction mode is in effect, then an UnconstructedParent object is returned instead.

Specified by:

evaluateItem in interface Expression

Overrides:

evaluateItem in class Instruction

Parameters:

context - The context in which the expression is to be evaluated

Returns:

the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence

Throws:

XPathException - if any dynamic error occurs evaluating the expression