org.jaxen.expr

Interface Predicate

public interface Predicate extends Serializable

Represents an XPath predicate such as [position() = last()]. This is production 8 and 9 in the XPath 1.0 specification:
 [8] Predicate     ::= '[' PredicateExpr ']'   
 [9] PredicateExpr ::= Expr
Method Summary
Objectevaluate(Context context)
Evaluates this predicate's expression and returns the result.
ExprgetExpr()
Returns the expression in this predicate.
StringgetText()
Returns the string form of the predicate, including the square brackets.
voidsetExpr(Expr expr)
Change the expression used by this predicate.
voidsimplify()
Simplify the expression in this predicate.

Method Detail

evaluate

public Object evaluate(Context context)
Evaluates this predicate's expression and returns the result. The result will be a java.lang.Double for expressions that return a number, a java.lang.String for expressions that return a string, a java.lang.Boolean for expressions that return a boolean, and a java.util.List for expressions that return a node-set. In the latter case, the elements of the list are the actual objects from the source document model. Copies are not made.

Parameters: context the context in which the expression is evaluated

Returns: an object representing the result of the evaluation

Throws: JaxenException

See Also: evaluate

getExpr

public Expr getExpr()
Returns the expression in this predicate.

Returns: the expression between the brackets

getText

public String getText()
Returns the string form of the predicate, including the square brackets.

Returns: the bracketed form of this predicate

setExpr

public void setExpr(Expr expr)
Change the expression used by this predicate.

Parameters: the new expression

simplify

public void simplify()
Simplify the expression in this predicate.

See Also: simplify