net.sf.saxon.instruct
Class Attribute

java.lang.Object
  extended bynet.sf.saxon.instruct.Instruction
      extended bynet.sf.saxon.instruct.ExprInstruction
          extended bynet.sf.saxon.instruct.SimpleNodeConstructor
              extended bynet.sf.saxon.instruct.Attribute
All Implemented Interfaces:
Expression, java.io.Serializable, javax.xml.transform.SourceLocator

public final class Attribute
extends SimpleNodeConstructor

An instruction derived from an xsl:attribute element in stylesheet, or from an attribute constructor in XQuery

See Also:
Serialized Form

Field Summary
 
Fields inherited from class net.sf.saxon.instruct.SimpleNodeConstructor
select, separator
 
Fields inherited from class net.sf.saxon.instruct.Instruction
children
 
Constructor Summary
Attribute(Expression attributeName, Expression namespace, NamespaceResolver nsContext, int validationAction, SimpleType schemaType, int annotation)
          Construct an Attribute instruction
 
Method Summary
 void display(int level, NamePool pool)
          Display this instruction as an expression, for diagnostics
protected  int evaluateNameCode(XPathContext context)
           
 int getDependencies()
          Determine which aspects of the context the expression depends on.
 SequenceType getResultType()
          Get the static type of the value returned by the instruction
 void getXPathExpressions(java.util.List list)
           
 TailCall processLeavingTail(XPathContext context)
          Process this instruction
 void promoteInst(PromotionOffer offer)
          Offer promotion for subexpressions.
 void setInstructionDetails(Controller controller, NamePool namePool, InstructionDetails details)
          Get the name of this instruction
 void setRejectDuplicates()
          Indicate that two attributes with the same name are not acceptable.
 Expression simplify()
          Simplify an expression.
 void typeCheck(StaticContext env)
           
 
Methods inherited from class net.sf.saxon.instruct.SimpleNodeConstructor
analyze, evaluateItem, expandChildren, setSelect, setSeparator
 
Methods inherited from class net.sf.saxon.instruct.ExprInstruction
effectiveBooleanValue, evaluateAsString, getCardinality, getItemType, getSpecialProperties, getSubExpressions, iterate, promote
 
Methods inherited from class net.sf.saxon.instruct.Instruction
assembleParams, assembleTunnelParams, getChildren, getColumnNumber, getInstructionDetails, getInstructionName, getLineNumber, getPublicId, getSystemId, getSystemId, process, processChildren, processChildrenLeavingTail, recoverableError, setChildren, setSourceLocation, styleError, styleError
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Attribute

public Attribute(Expression attributeName,
                 Expression namespace,
                 NamespaceResolver nsContext,
                 int validationAction,
                 SimpleType schemaType,
                 int annotation)
Construct an Attribute instruction

Parameters:
attributeName - An expression to calculate the attribute name
namespace - An expression to calculate the attribute namespace
nsContext - a NamespaceContext object containing the static namespace context of the stylesheet instruction
annotation - Integer code identifying the type named in the type attribute of the instruction - zero if the attribute was not present
Method Detail

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)


setInstructionDetails

public void setInstructionDetails(Controller controller,
                                  NamePool namePool,
                                  InstructionDetails details)
Get the name of this instruction

Specified by:
setInstructionDetails in class Instruction

getResultType

public SequenceType getResultType()
Description copied from class: Instruction
Get the static type of the value returned by the instruction

Overrides:
getResultType in class Instruction
Returns:
the SequenceType that the returned value will conform to.

simplify

public Expression simplify()
                    throws XPathException
Description copied from interface: Expression
Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression). The default implementation does nothing.

Specified by:
simplify in interface Expression
Overrides:
simplify in class ExprInstruction
Throws:
XPathException

typeCheck

public void typeCheck(StaticContext env)
               throws XPathException
Specified by:
typeCheck in class SimpleNodeConstructor
Throws:
XPathException

getDependencies

public int getDependencies()
Description copied from interface: Expression
Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as XPathContext.VARIABLES and XPathContext.CURRENT_NODE. The default implementation combines the intrinsic dependencies of this expression with the dependencies of the subexpressions, computed recursively. This is overridden for expressions such as FilterExpression where a subexpression's dependencies are not necessarily inherited by the parent expression.

Specified by:
getDependencies in interface Expression
Overrides:
getDependencies in class ExprInstruction

getXPathExpressions

public void getXPathExpressions(java.util.List list)
Overrides:
getXPathExpressions in class SimpleNodeConstructor

promoteInst

public void promoteInst(PromotionOffer offer)
                 throws XPathException
Offer promotion for subexpressions. The offer will be accepted if the subexpression is not dependent on the factors (e.g. the context item) identified in the PromotionOffer. By default the offer is not accepted - this is appropriate in the case of simple expressions such as constant values and variable references where promotion would give no performance advantage. This method is always called at compile time.

Specified by:
promoteInst in class ExprInstruction
Parameters:
offer - details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression
Throws:
XPathException - if any error is detected

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws javax.xml.transform.TransformerException
Process this instruction

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:
javax.xml.transform.TransformerException

evaluateNameCode

protected int evaluateNameCode(XPathContext context)
                        throws XPathException,
                               javax.xml.transform.TransformerException
Overrides:
evaluateNameCode in class SimpleNodeConstructor
Throws:
XPathException
javax.xml.transform.TransformerException

display

public void display(int level,
                    NamePool pool)
Display this instruction as an expression, for diagnostics

Specified by:
display in interface Expression
Overrides:
display in class SimpleNodeConstructor