net.sf.saxon.instruct
Class FixedElement

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.instruct.Instruction
          net.sf.saxon.instruct.ParentNodeConstructor
              net.sf.saxon.instruct.ElementCreator
                  net.sf.saxon.instruct.FixedElement

All Implemented Interfaces:

Serializable, SourceLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfoProvider

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.

See Also:

Serialized Form

Field Summary

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

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.
Expression	simplify(ExpressionVisitor visitor) Simplify an expression.

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

computeSpecialProperties, evaluateItem, getImplementationMethod, isInheritNamespaces, isPreservingTypes, iterateEvents, processLeavingTail, setValidationMode, suppressValidation

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

addToPathMap, computeCardinality, createsNewNodes, getBaseURI, getCardinality, getContentExpression, getSchemaType, getValidationMode, isLazyConstruction, isNamespaceSensitive, iterateSubExpressions, replaceSubExpression, setBaseURI, setContentExpression, setLazyConstruction, setSchemaType, typeCheck

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

evaluateAsString, getInstructionNameCode, getSourceLocator, isXSLT, iterate, process, promote

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

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

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 Detail

getInstructionInfo

public InstructionInfo getInstructionInfo()

Description copied from class: Expression

Get InstructionInfo for this expression

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 context-independent rewriting

Overrides:

simplify in class ParentNodeConstructor

Parameters:

visitor - the expression visitor

Returns:

the simplified expression

Throws:

XPathException - if an error is discovered during expression rewriting

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 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)

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

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

getItemType

public ItemType getItemType(TypeHierarchy th)

Get the type of the item returned by this instruction

Overrides:

getItemType in class 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

Specified by:

getNameCode in class ElementCreator

Parameters:

context - The evaluation context (not used)

Returns:

the name code for the element name

getNewBaseURI

public String getNewBaseURI(XPathContext context)

Description copied from class: ElementCreator

Get the base URI for the element being constructed

Specified by:

getNewBaseURI in class ElementCreator

Parameters:

context - the XPath dynamic evaluation context

Returns:

the base URI of the constructed element

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 class Expression

Parameters:

parentType - the "given complex type": the method is checking that the nodes returned by this expression are acceptable members of the content model of this type

env - the static context

whole - if true, we want to check that the value of this expression satisfies the content model as a whole; if false we want to check that the value of the expression is acceptable as one part of the content

Throws:

XPathException - if the value delivered by this expression cannot be part of the content model of the given type

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 class ElementCreator

Returns:

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.

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