net.sf.saxon.instruct
Class FixedAttribute

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.instruct.Instruction
          net.sf.saxon.instruct.SimpleNodeConstructor
              net.sf.saxon.instruct.FixedAttribute

All Implemented Interfaces:

Serializable, SourceLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfoProvider

public final class FixedAttribute
extends SimpleNodeConstructor

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.

See Also:

Serialized Form

Field Summary

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

FixedAttribute(int nameCode, int validationAction, SimpleType schemaType, int annotation)
Construct an Attribute instruction

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.
Item	evaluateItem(XPathContext context) Evaluate as an expression.
int	evaluateNameCode(XPathContext context) Run-time method to compute the name of the node being constructed.
void	explain(ExpressionPresenter out) Diagnostic print of expression structure.
int	getAttributeNameCode() Get the name pool name code of the attribute to be constructed
int	getCardinality() Determine the static cardinality of the expression.
InstructionInfo	getInstructionInfo() Get InstructionInfo for this expression
int	getInstructionNameCode() Get the name of this instruction (return 'xsl:attribute')
ItemType	getItemType(TypeHierarchy th) Get the item type of the items returned by evaluating this instruction
int	getValidationAction() Get the validation action requested
void	localTypeCheck(ExpressionVisitor visitor, ItemType contextItemType) Method to perform type-checking specific to the kind of instruction
TailCall	processLeavingTail(XPathContext context) Process this instruction
void	setNoSpecialChars() Indicate that the attribute value contains no special characters that might need escaping
void	setRejectDuplicates() Indicate that two attributes with the same name are not acceptable.
void	setSelect(Expression select, Configuration config) Set the expression defining the value of the attribute.

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

computeCardinality, computeSpecialProperties, createsNewNodes, expandChildren, getSelect, iterate, iterateSubExpressions, optimize, replaceSubExpression, simplify, typeCheck

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

evaluateAsString, getImplementationMethod, getSourceLocator, isXSLT, process, promote

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

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

FixedAttribute

public FixedAttribute(int nameCode,
                      int validationAction,
                      SimpleType schemaType,
                      int annotation)

Construct an Attribute instruction

Parameters:

nameCode - 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

annotation - Integer code identifying the type named in the type attribute 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

setRejectDuplicates

public void setRejectDuplicates()

Indicate that two attributes with the same name are not acceptable. (This option is set in XQuery, but not in XSLT)

setNoSpecialChars

public void setNoSpecialChars()

Indicate that the attribute value contains no special characters that might need escaping

setSelect

public void setSelect(Expression select,
                      Configuration config)
               throws XPathException

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

config - The Saxon configuration

Throws:

XPathException - if the expression is a constant, and validation is requested, and the constant doesn't match the required type.

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

getAttributeNameCode

public int getAttributeNameCode()

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

Returns:

the attribute's name code

getItemType

public ItemType getItemType(TypeHierarchy th)

Description copied from class: Instruction

Get the item type of the items returned by evaluating this instruction

Overrides:

getItemType in class Instruction

Parameters:

th - the type hierarchy cache

Returns:

the static item type of the instruction

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).

getValidationAction

public int getValidationAction()

Get the validation action requested

Returns:

the validation action, for example strict or lax

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

localTypeCheck

public void localTypeCheck(ExpressionVisitor visitor,
                           ItemType contextItemType)

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

evaluateNameCode

public int evaluateNameCode(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:

evaluateNameCode 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,
                                   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

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws XPathException

Process this instruction

Specified by:

processLeavingTail in interface TailCallReturner

Specified by:

processLeavingTail in class Instruction

Parameters:

context - the dynamic context of the transformation

Returns:

a TailCall to be executed by the caller, always null for this instruction

Throws:

XPathException

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException

Description copied from class: SimpleNodeConstructor

Evaluate as an expression. We rely on the fact that when these instructions are generated by XQuery, there will always be a valueExpression to evaluate the content

Specified by:

evaluateItem in interface EvaluableItem

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

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