com.icl.saxon.expr
Class AttributeReference

java.lang.Object
  extended bycom.icl.saxon.expr.Expression
      extended bycom.icl.saxon.expr.NodeSetExpression
          extended bycom.icl.saxon.expr.SingletonExpression
              extended bycom.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
AttributeReference(int fingerprint)
          Constructor
 
Method Summary
 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.
 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 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