com.icl.saxon.expr

Class AttributeReference

java.lang.Object

com.icl.saxon.expr.Expression

com.icl.saxon.expr.NodeSetExpression

com.icl.saxon.expr.SingletonExpression

com.icl.saxon.expr.AttributeReference

 class AttributeReference
extends SingletonExpression

An expression that represents a reference to a named attribute

Field Summary

Fields inherited from class com.icl.saxon.expr.Expression

staticContext

Constructor Summary

Constructors

Constructor and Description
AttributeReference(int fingerprint) Constructor

Method Summary

Methods

Modifier and Type	Method and Description
void	bindParentNode(NodeInfo node) Bind the reference to a particular node
void	display(int level) Diagnostic print of expression structure
boolean	evaluateAsBoolean(Context context) Evaluate as a boolean.
java.lang.String	evaluateAsString(Context context) Evaluate as a string.
int	getDependencies() Determine which aspects of the context the expression depends on.
NodeInfo	getNode(Context context) Return the relevant attribute node
Expression	reduce(int dependencies, Context context) Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

Methods inherited from class com.icl.saxon.expr.SingletonExpression

enumerate, evaluateAsNodeSet, isContextDocumentNodeSet, selectFirst

Methods inherited from class com.icl.saxon.expr.NodeSetExpression

evaluate, getDataType, outputStringValue

Methods inherited from class com.icl.saxon.expr.Expression

containsReferences, evaluateAsNumber, getStaticContext, indent, make, setStaticContext, simplify, usesCurrent

Methods inherited from class java.lang.Object

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

Constructor Detail

AttributeReference

public AttributeReference(int fingerprint)

Constructor

Method Detail

bindParentNode

public void bindParentNode(NodeInfo node)

Bind the reference to a particular node

getNode

public NodeInfo getNode(Context context)
                 throws XPathException

Return the relevant attribute node

Specified by:

getNode in class SingletonExpression

Parameters:

context - the evaluation context

Throws:

XPathException

evaluateAsBoolean

public boolean evaluateAsBoolean(Context context)
                          throws XPathException

Evaluate as a boolean. Returns true if there are any nodes selected by the NodeSetExpression

Overrides:

evaluateAsBoolean in class SingletonExpression

Parameters:

context - The context in which the expression is to be evaluated

Returns:

true if there are any nodes selected by the NodeSetExpression

Throws:

XPathException

evaluateAsString

public java.lang.String evaluateAsString(Context context)
                                  throws XPathException

Evaluate as a string. Returns the string value of the attribute if it exists

Overrides:

evaluateAsString in class SingletonExpression

Parameters:

context - The context in which the expression is to be evaluated

Returns:

true if there are any nodes selected by the NodeSetExpression

Throws:

XPathException

getDependencies

public int getDependencies()

Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as Context.VARIABLES and Context.CURRENT_NODE

Specified by:

getDependencies in class Expression

reduce

public Expression reduce(int dependencies,
                Context context)
                  throws XPathException

Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

Specified by:

reduce in class Expression

Parameters:

dependencies - The dependencies to be removed

context - The context to be used for the partial evaluation

Returns:

a new expression that does not have any of the specified dependencies

Throws:

XPathException

display

public void display(int level)

Diagnostic print of expression structure

Specified by:

display in class Expression