org.jaxen.expr

Interface Expr

All Superinterfaces:

Serializable

All Known Subinterfaces:

AdditiveExpr, BinaryExpr, EqualityExpr, FilterExpr, FunctionCallExpr, LiteralExpr, LocationPath, LogicalExpr, MultiplicativeExpr, NumberExpr, PathExpr, RelationalExpr, UnaryExpr, UnionExpr, VariableReferenceExpr

All Known Implementing Classes:

DefaultFilterExpr

public interface Expr
extends Serializable

Represents an XPath expression. This is production 14 in the XPath 1.0 specification:

[14]      Expr       ::=      OrExpr

Method Summary

Modifier and Type	Method and Description
Object	evaluate(Context context) Evaluate the expression in the given context, and return the result.
String	getText() Returns a String containing the XPath expression.
Expr	simplify() Simplifies the XPath expression.

Method Detail

getText

String getText()

Returns a String containing the XPath expression.

Returns:

the text form of this XPath expression

simplify

Expr simplify()

Simplifies the XPath expression. For example, the expression //para[1 = 1] could be simplified to //para. In practice, this is usually a noop. Jaxen does not currently perform any simplification.

Returns:

the simplified expression

evaluate

Object evaluate(Context context)
         throws JaxenException

Evaluate the expression in the given context, and return 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