com.icl.saxon.expr

Class ParentNodeExpression

public class ParentNodeExpression extends SingletonExpression

Class ParentNodeExpression represents the XPath expression ".." or "parent::node()"
Method Summary
voiddisplay(int level)
Diagnostic print of expression structure
booleanevaluateAsBoolean(Context context)
Evaluate as a boolean.
StringevaluateAsString(Context context)
Evaluate as a string.
intgetDependencies()
Determine which aspects of the context the expression depends on.
NodeInfogetNode(Context context)
Return the node selected by this SingletonExpression
Expressionreduce(int dependencies, Context context)
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

Method Detail

display

public void display(int level)
Diagnostic print of expression structure

evaluateAsBoolean

public boolean evaluateAsBoolean(Context context)
Evaluate as a boolean. Returns true if there are any nodes selected by the NodeSetExpression.

Parameters: context The context in which the expression is to be evaluated

Returns: true unless the current node is the Document node

evaluateAsString

public String evaluateAsString(Context context)
Evaluate as a string. Returns the string value of the parent node

Parameters: context The context in which the expression is to be evaluated

Returns: the value of the current node, identified by the context

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

getNode

public NodeInfo getNode(Context context)
Return the node selected by this SingletonExpression

Parameters: context The context for the evaluation

Returns: the parent of the current node defined by the context

reduce

public Expression reduce(int dependencies, Context context)
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

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