net.sf.saxon.expr.instruct

Class FixedAttribute

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.instruct.Instruction

net.sf.saxon.expr.instruct.SimpleNodeConstructor

net.sf.saxon.expr.instruct.AttributeCreator

net.sf.saxon.expr.instruct.FixedAttribute

All Implemented Interfaces:

TailCallReturner, ValidatingInstruction, IdentityComparable

public final class FixedAttribute
extends AttributeCreator

An instruction derived from an xsl:attribute element in stylesheet, or from an attribute constructor in XQuery. This version deals only with attributes whose name is known at compile time. It is also used for attributes of literal result elements. The value of the attribute is in general computed at run-time.

Field Summary

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

selectOp

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

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

Constructor Summary

Constructors

Constructor and Description
FixedAttribute(NodeName nodeName, int validationAction, SimpleType schemaType) Construct an Attribute instruction

Method Summary

Methods

Modifier and Type	Method and Description
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() Copy an expression.
NodeInfo	evaluateItem(XPathContext context) Evaluate as an expression.
NodeName	evaluateNodeName(XPathContext context) Run-time method to compute the name of the node being constructed.
void	export(ExpressionPresenter out) Diagnostic print of expression structure.
NodeName	getAttributeName()
int	getAttributeNameCode() Get the name pool name code of the attribute to be constructed
int	getCardinality() Determine the static cardinality of the expression.
ExpressionCompiler	getExpressionCompiler() Return the compiler of the FixedAttribute expression
int	getInstructionNameCode() Get the name of this instruction (return 'xsl:attribute')
void	localTypeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) Method to perform type-checking specific to the kind of instruction
void	setSelect(Expression select) Set the expression defining the value of the attribute.

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

computeSpecialProperties, getItemType, getOptions, getSchemaType, getValidationAction, processValue, setNoSpecialChars, setOptions, setRejectDuplicates, setSchemaType, setValidationAction, validateOrphanAttribute

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

checkContent, computeCardinality, createsNewNodes, getSelect, getStreamingAdjunct, iterate, operands, optimize, processLeavingTail, promoteChildren, typeCheck

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

assembleParams, assembleTunnelParams, dynamicError, evaluateAsString, getConstructType, getExpressionName, getImplementationMethod, getInstructionName, getNetCost, getSourceLocator, isXSLT, main, process, toStreamingPattern

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

addToPathMap, adoptChildExpression, checkedOperands, checkForUpdatingSubexpressions, clearStreamabilityData, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, getConfiguration, getCost, getDependencies, getEvaluationMethod, getHostLanguage, getIntegerBounds, getIntrinsicDependencies, getLocation, getObjectName, getPackageData, getParentExpression, getPosture, getPostureAndSweepIfKnown, getProperties, getProperty, getRetainedStaticContext, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStreamability, getSweep, getSystemId, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isCallOnSystemFunction, isIdentical, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, makeStreamingAdjunct, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, optimizeForType, promote, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setFiltered, setFlattened, setLocation, setParentExpression, setPostureAndSweep, setRetainedStaticContext, setRetainedStaticContextLocally, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, toShortString, toString, typeCheckChildren, typeError, unordered

Methods inherited from class java.lang.Object

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

Constructor Detail

FixedAttribute

public FixedAttribute(NodeName nodeName,
              int validationAction,
              SimpleType schemaType)

Construct an Attribute instruction

Parameters:

nodeName - Represents the attribute name

validationAction - the validation required, for example strict or lax

schemaType - the schema type against which validation is required, null if not applicable of the instruction - zero if the attribute was not present

Method Detail

getInstructionNameCode

public int getInstructionNameCode()

Get the name of this instruction (return 'xsl:attribute')

Overrides:

getInstructionNameCode in class Instruction

Returns:

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

getAttributeName

public NodeName getAttributeName()

setSelect

public void setSelect(Expression select)

Set the expression defining the value of the attribute. If this is a constant, and if validation against a schema type was requested, the validation is done immediately.

Overrides:

setSelect in class SimpleNodeConstructor

Parameters:

select - The expression defining the content of the attribute

localTypeCheck

public void localTypeCheck(ExpressionVisitor visitor,
                  ContextItemStaticInfo contextItemType)
                    throws XPathException

Description copied from class: SimpleNodeConstructor

Method to perform type-checking specific to the kind of instruction

Specified by:

localTypeCheck in class SimpleNodeConstructor

Parameters:

visitor - an expression visitor

contextItemType - the static type of the context item

Throws:

XPathException - if a type error is detected

getAttributeNameCode

public int getAttributeNameCode()

Get the name pool name code of the attribute to be constructed

Returns:

the attribute's name code

getCardinality

public int getCardinality()

Description copied from class: Expression

Determine the static cardinality of the expression. This establishes how many items there will be in the result of the expression, at compile time (i.e., without actually evaluating the result.

Overrides:

getCardinality in class Expression

Returns:

one of the values Cardinality.ONE_OR_MORE, Cardinality.ZERO_OR_MORE, Cardinality.EXACTLY_ONE, Cardinality.ZERO_OR_ONE, Cardinality.EMPTY. This default implementation returns ZERO_OR_MORE (which effectively gives no information).

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

evaluateNodeName

public NodeName evaluateNodeName(XPathContext context)

Description copied from class: SimpleNodeConstructor

Run-time method to compute the name of the node being constructed. This is overridden for nodes that have a name. The default implementation returns -1, which is suitable for unnamed nodes such as comments

Overrides:

evaluateNodeName in class SimpleNodeConstructor

Parameters:

context - the XPath dynamic evaluation context

Returns:

the name pool nameCode identifying the name of the constructed node

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

evaluateItem

public NodeInfo evaluateItem(XPathContext context)
                      throws XPathException

Description copied from class: SimpleNodeConstructor

Evaluate as an expression.

Overrides:

evaluateItem in class SimpleNodeConstructor

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

getExpressionCompiler

public ExpressionCompiler getExpressionCompiler()

Return the compiler of the FixedAttribute expression

Overrides:

getExpressionCompiler in class Expression

Returns:

the relevant ExpressionCompiler

export

public void export(ExpressionPresenter out)

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

Specified by:

export in class Expression

Parameters:

out - the expression presenter used to display the structure