net.sf.saxon.instruct

Class FixedElement

Implemented Interfaces:
SourceLocator, EvaluableItem, InstructionInfoProvider, SequenceIterable, Serializable, SourceLocator, TailCallReturner

public class FixedElement
extends ElementCreator

An instruction that creates an element node whose name is known statically. Used for literal results elements in XSLT, for direct element constructors in XQuery, and for xsl:element in cases where the name and namespace are known statically.

Field Summary

protected int[]
namespaceCodes

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

inheritNamespaces, preservingTypes

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

content

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD, locationId, staticProperties

Constructor Summary

FixedElement(int nameCode, int[] namespaceCodes, boolean inheritNamespaces, SchemaType schemaType, int validation)
Create an instruction that creates a new element node

Method Summary

void
checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole)
Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type.
Expression
copy()
Copy an expression.
void
explain(ExpressionPresenter out)
Diagnostic print of expression structure.
int[]
getActiveNamespaces()
Callback to get a list of the intrinsic namespaces that need to be generated for the element.
InstructionInfo
getInstructionInfo()
Get InstructionInfo for this expression
ItemType
getItemType(TypeHierarchy th)
Get the type of the item returned by this instruction
int
getNameCode(XPathContext context)
Callback from the superclass ElementCreator to get the nameCode for the element name
String
getNewBaseURI(XPathContext context)
Get the base URI for the element being constructed
short
getURICode(NamePool pool)
Get the URI code representing the namespace URI of the element being constructed
Expression
optimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
protected void
outputNamespaceNodes(XPathContext context, Receiver out)
Callback from the superclass ElementCreator to output the namespace nodes
Expression
simplify(ExpressionVisitor visitor)
Simplify an expression.

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

checkContentSequence, computeSpecialProperties, evaluateItem, getActiveNamespaces, getImplementationMethod, getItemType, getNameCode, getNewBaseURI, isInheritNamespaces, isPreservingTypes, iterateEvents, outputNamespaceNodes, processLeavingTail, setValidationMode, suppressValidation

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

addToPathMap, checkContentSequence, computeCardinality, createsNewNodes, getBaseURI, getCardinality, getContentExpression, getSchemaType, getValidationMode, isLazyConstruction, isNamespaceSensitive, iterateSubExpressions, optimize, promoteInst, replaceSubExpression, setBaseURI, setContentExpression, setLazyConstruction, setSchemaType, setValidationMode, simplify, typeCheck

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

assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, createsNewNodes, dynamicError, evaluateAsString, evaluateItem, getImplementationMethod, getInstructionInfo, getInstructionNameCode, getItemType, getSourceLocator, isXSLT, iterate, process, processLeavingTail, promote, promoteInst, simplify

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

addToPathMap, adoptChildExpression, checkPermittedContents, computeCardinality, computeDependencies, computeSpecialProperties, computeStaticProperties, copy, display, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, explain, explain, findParentOf, getCardinality, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getItemType, getLineNumber, getLocationId, getLocationProvider, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, iterate, iterateEvents, iterateSubExpressions, markTailFunctionCalls, optimize, process, promote, replaceSubExpression, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, simplify, staticTypeCheck, suppressValidation, toString, typeCheck, typeError

Field Details

namespaceCodes

protected int[] namespaceCodes

Constructor Details

FixedElement

public FixedElement(int nameCode,
                    int[] namespaceCodes,
                    boolean inheritNamespaces,
                    SchemaType schemaType,
                    int validation)
Create an instruction that creates a new element node
Parameters:
nameCode - Represents the name of the element node
namespaceCodes - List of namespaces to be added to the element node. May be null if none are required.
inheritNamespaces - true if the children of this element are to inherit its namespaces
schemaType - Type annotation for the new element node
validation - Validation mode to be applied, for example STRICT, LAX, SKIP

Method Details

checkPermittedContents

public void checkPermittedContents(SchemaType parentType,
                                   StaticContext env,
                                   boolean whole)
            throws XPathException
Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type. It's always OK to say yes, since the check will be repeated at run-time. The process of checking element and attribute constructors against the content model of a complex type also registers the type of content expected of those constructors, so the static validation can continue recursively.
Overrides:
checkPermittedContents in interface Expression

copy

public Expression copy()
Copy an expression. This makes a deep copy.
Overrides:
copy in interface Expression
Returns:
the copy of the original expression

explain

public void explain(ExpressionPresenter out)
Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
Overrides:
explain in interface Expression

getActiveNamespaces

public int[] getActiveNamespaces()
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.
Overrides:
getActiveNamespaces in interface ElementCreator

getInstructionInfo

public InstructionInfo getInstructionInfo()
Get InstructionInfo for this expression
Specified by:
getInstructionInfo in interface InstructionInfoProvider
Overrides:
getInstructionInfo in interface Instruction

getItemType

public ItemType getItemType(TypeHierarchy th)
Get the type of the item returned by this instruction
Overrides:
getItemType in interface ElementCreator
Parameters:
th - The type hierarchy cache
Returns:
the item type

getNameCode

public int getNameCode(XPathContext context)
Callback from the superclass ElementCreator to get the nameCode for the element name
Overrides:
getNameCode in interface ElementCreator
Parameters:
context - The evaluation context (not used)
Returns:
the name code for the element name

getNewBaseURI

public String getNewBaseURI(XPathContext context)
Get the base URI for the element being constructed
Overrides:
getNewBaseURI in interface ElementCreator
Parameters:
context - the XPath dynamic evaluation context
Returns:
the base URI of the constructed element

getURICode

public short getURICode(NamePool pool)
Get the URI code representing the namespace URI of the element being constructed
Parameters:
pool - the NamePool
Returns:
the URI code

optimize

public Expression optimize(ExpressionVisitor visitor,
                           ItemType contextItemType)
            throws XPathException
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 interface ParentNodeConstructor
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)

outputNamespaceNodes

protected void outputNamespaceNodes(XPathContext context,
                                    Receiver out)
            throws XPathException
Callback from the superclass ElementCreator to output the namespace nodes
Overrides:
outputNamespaceNodes in interface ElementCreator
Parameters:
context - The evaluation context (not used)
out - The receiver to handle the output

simplify

public Expression simplify(ExpressionVisitor visitor)
            throws XPathException
Simplify an expression. This performs any context-independent rewriting
Overrides:
simplify in interface ParentNodeConstructor
Parameters:
visitor - the expression visitor
Returns:
the simplified expression
Throws:
XPathException - if an error is discovered during expression rewriting