net.sf.saxon.expr.instruct

Class FixedElement

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.instruct.Instruction

net.sf.saxon.expr.instruct.ParentNodeConstructor

net.sf.saxon.expr.instruct.ElementCreator

net.sf.saxon.expr.instruct.FixedElement

All Implemented Interfaces:

ExportAgent, InstructionWithComplexContent, TailCallReturner, ValidatingInstruction, Locatable, IdentityComparable

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

Fields

Modifier and Type	Field and Description
protected NamespaceBinding[]	namespaceBindings

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

inheritNamespacesFromParent, inheritNamespacesToChildren

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

contentOp, preservingTypes

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

EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_COST, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD

Constructor Summary

Constructors

Constructor and Description
FixedElement(NodeName elementName, NamespaceBinding[] namespaceBindings, boolean inheritNamespacesToChildren, boolean inheritNamespacesFromParent, SchemaType schemaType, int validation) Create an instruction that creates a new element node

Method Summary

Modifier and Type	Method and Description
protected void	checkContentSequence(StaticContext env) Check statically whether the content of the element creates attributes or namespaces after creating any child nodes
void	checkPermittedContents(SchemaType parentType, 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(RebindingMap rebindings) Copy an expression.
void	export(ExpressionPresenter out) Diagnostic print of expression structure.
NamespaceBinding[]	getActiveNamespaces() Callback to get a list of the intrinsic namespaces that need to be generated for the element.
NodeName	getElementName()
NodeName	getElementName(XPathContext context, NodeInfo copiedNode) Callback from the superclass ElementCreator to get the nameCode for the element name
java.lang.String	getExpressionName() Get a name identifying the kind of expression, in terms meaningful to a user.
ItemType	getItemType() Get the type of the item returned by this instruction
java.lang.String	getNewBaseURI(XPathContext context, NodeInfo copiedNode) Get the base URI for the element being constructed
java.lang.Iterable<Operand>	operands() Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.
Expression	optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) Perform optimisation of an expression and its subexpressions.
void	outputNamespaceNodes(XPathContext context, Receiver out, NodeName nameCode, NodeInfo copiedNode) Callback from the superclass ElementCreator to output the namespace nodes
Expression	simplify() Simplify an expression.
java.lang.String	toShortString() Produce a short string identifying the expression for use in error messages
java.lang.String	toString() The toString() method for an expression attempts to give a representation of the expression in an XPath-like form.

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

computeSpecialProperties, evaluateItem, exportValidationAndType, getCardinality, getImplementationMethod, getInheritanceFlags, getStreamerName, isInheritNamespacesFromParent, isInheritNamespacesToChildren, processLeavingTail, processLeavingTail, setInheritanceFlags, setInheritNamespacesFromParent, setInheritNamespacesToChildren, suppressValidation

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

addToPathMap, allowExtractingCommonSubexpressions, alwaysCreatesNewNodes, computeCardinality, getContentExpression, getContentOperand, getSchemaType, getValidationAction, getValidationOptions, isLazyConstruction, isLocal, isPreservingTypes, mayCreateNewNodes, setBaseURI, setContentExpression, setLazyConstruction, setNoNeedToStrip, setValidationAction, typeCheck

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

assembleParams, assembleTunnelParams, dynamicError, evaluateAsString, getConstructType, getInstructionNameCode, getNetCost, getSourceLocator, isInstruction, isXSLT, iterate, process, someOperandCreatesNewNodes

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

adoptChildExpression, checkedOperands, checkForUpdatingSubexpressions, computeDependencies, computeHashCode, computeStaticProperties, dynamicError, effectiveBooleanValue, equals, evaluatePendingUpdates, explain, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, prepareForStreaming, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplifyChildren, staticTypeCheck, toPattern, typeCheckChildren, typeError, unordered, verifyParentPointers

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

namespaceBindings

protected NamespaceBinding[] namespaceBindings

Constructor Detail

FixedElement

public FixedElement(NodeName elementName,
                    NamespaceBinding[] namespaceBindings,
                    boolean inheritNamespacesToChildren,
                    boolean inheritNamespacesFromParent,
                    SchemaType schemaType,
                    int validation)

Create an instruction that creates a new element node

Parameters:

elementName - Represents the name of the element node

namespaceBindings - List of namespaces to be added to the element node. Supply an empty array if none are required.

inheritNamespacesToChildren - true if the children of this element inherit its namespaces

inheritNamespacesFromParent - true if this element inherits namespaces from its parent

schemaType - Type annotation for the new element node

validation - Validation mode to be applied, for example STRICT, LAX, SKIP

Method Detail

operands

public java.lang.Iterable<Operand> operands()

Description copied from class: Expression

Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression. Default implementation works off the results of iterateSubExpressions()

If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.

Specified by:

operands in class Instruction

Returns:

an iterator containing the sub-expressions of this expression

simplify

public Expression simplify()
                    throws XPathException

Simplify an expression. This performs any context-independent rewriting

Overrides:

simplify in class Expression

Returns:

the simplified expression (or the original if unchanged, or if modified in-situ)

Throws:

XPathException - if an error is discovered during expression rewriting

checkContentSequence

protected void checkContentSequence(StaticContext env)
                             throws XPathException

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

Overrides:

checkContentSequence in class ElementCreator

Parameters:

env - the static context

Throws:

XPathException - if the content sequence is invalid

optimize

public Expression optimize(ExpressionVisitor visitor,
                           ContextItemStaticInfo 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(RebindingMap rebindings)

Copy an expression. This makes a deep copy.

Specified by:

copy in class Expression

Parameters:

rebindings - a mutable list of (old binding, new binding) pairs that is used to update the bindings held in any local variable references that are copied.

Returns:

the copy of the original expression

getItemType

public ItemType getItemType()

Get the type of the item returned by this instruction

Overrides:

getItemType in class ElementCreator

Returns:

the item type

getElementName

public NodeName getElementName(XPathContext context,
                               NodeInfo copiedNode)

Callback from the superclass ElementCreator to get the nameCode for the element name

Specified by:

getElementName in class ElementCreator

Parameters:

context - The evaluation context (not used)

copiedNode - For the benefit of the xsl:copy instruction, the node to be copied

Returns:

the name code for the element name

getElementName

public NodeName getElementName()

getNewBaseURI

public java.lang.String getNewBaseURI(XPathContext context,
                                      NodeInfo copiedNode)

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

copiedNode - the node being copied (for xsl:copy), otherwise null

Returns:

the base URI of the constructed element

checkPermittedContents

public void checkPermittedContents(SchemaType parentType,
                                   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

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

outputNamespaceNodes

public void outputNamespaceNodes(XPathContext context,
                                 Receiver out,
                                 NodeName nameCode,
                                 NodeInfo copiedNode)
                          throws XPathException

Callback from the superclass ElementCreator to output the namespace nodes

Specified by:

outputNamespaceNodes in class ElementCreator

Parameters:

context - The evaluation context (not used)

out - The receiver to handle the output

nameCode - the name of this element

copiedNode - in the case of xsl:copy, the node being copied

Throws:

XPathException - if a dynamic error occurs

getActiveNamespaces

public NamespaceBinding[] 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:

the set of namespace bindings.

export

public void export(ExpressionPresenter out)
            throws XPathException

Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.

Specified by:

export in interface ExportAgent

Specified by:

export in class Expression

Parameters:

out - the expression presenter used to display the structure

Throws:

XPathException - if the export fails, for example if an expression is found that won't work in the target environment.

toString

public java.lang.String toString()

Description copied from class: Expression

The toString() method for an expression attempts to give a representation of the expression in an XPath-like form.

For subclasses of Expression that represent XPath expressions, the result should always be a string that parses as an XPath 3.0 expression. The expression produced should be equivalent to the original making certain assumptions about the static context. In general the expansion will make no assumptions about namespace bindings, except that (a) the prefix "xs" is used to refer to the XML Schema namespace, and (b) the default function namespace is assumed to be the "fn" namespace.

In the case of XSLT instructions and XQuery expressions, the toString() method gives an abstracted view of the syntax that is not designed in general to be parseable.

Overrides:

toString in class Expression

Returns:

a representation of the expression as a string

toShortString

public java.lang.String toShortString()

Description copied from class: Expression

Produce a short string identifying the expression for use in error messages

Overrides:

toShortString in class Expression

Returns:

a short string, sufficient to identify the expression

getExpressionName

public java.lang.String getExpressionName()

Get a name identifying the kind of expression, in terms meaningful to a user.

Overrides:

getExpressionName in class Instruction

Returns:

a name identifying the kind of expression, in terms meaningful to a user. The name will always be in the form of a lexical XML QName, and should match the name used in explain() output displaying the expression.