org.javarosa.xpath.expr

Class XPathExpression

java.lang.Object

org.javarosa.xpath.expr.XPathExpression

All Implemented Interfaces:

Serializable, Externalizable

Direct Known Subclasses:

XPathFilterExpr, XPathFuncExpr, XPathNumericLiteral, XPathOpExpr, XPathPathExpr, XPathStringLiteral, XPathVariableReference

public abstract class XPathExpression
extends Object
implements Externalizable, Serializable

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
XPathExpression()

Method Summary

Modifier and Type	Method and Description
abstract Object	eval(DataInstance model, EvaluationContext evalContext)
Object	eval(EvaluationContext evalContext)
int	hashCode()
List<Object>	pivot(DataInstance model, EvaluationContext evalContext)
Object	pivot(DataInstance model, EvaluationContext evalContext, List<Object> pivots, Object sentinal) Pivot this expression, returning values if appropriate, and adding any pivots to the list.
void	print(Object o)
void	printParseTree()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.javarosa.core.util.externalizable.Externalizable

readExternal, writeExternal

Constructor Detail

XPathExpression

public XPathExpression()

Method Detail

eval

public Object eval(EvaluationContext evalContext)

eval

public abstract Object eval(DataInstance model,
                            EvaluationContext evalContext)

pivot

public final List<Object> pivot(DataInstance model,
                                EvaluationContext evalContext)
                         throws UnpivotableExpressionException

Throws:

UnpivotableExpressionException

pivot

public Object pivot(DataInstance model,
                    EvaluationContext evalContext,
                    List<Object> pivots,
                    Object sentinal)
             throws UnpivotableExpressionException

Pivot this expression, returning values if appropriate, and adding any pivots to the list.

Parameters:

model - The model to evaluate the current expression against

evalContext - The evaluation context to evaluate against

pivots - The list of pivot points in the xpath being evaluated. Pivots should be added to this list.

sentinal - The value which is being pivoted around.

Returns:

null - If a pivot was identified in this expression sentinal - If the current expression represents the sentinal being pivoted any other value - The result of the expression if no pivots are detected

Throws:

UnpivotableExpressionException - If the expression is too complex to pivot

printParseTree

public void printParseTree()

print

public void print(Object o)

hashCode

public int hashCode()

Overrides:

hashCode in class Object