org.jaxen.function

Class BooleanFunction

public class BooleanFunction extends Object implements Function

4.3 boolean boolean(object)

The boolean function converts its argument to a boolean as follows:

Author: bob mcwhirter (bob @ werken.com)

See Also: Section 4.3 of the XPath Specification

Constructor Summary
BooleanFunction()
Create a new BooleanFunction object.
Method Summary
Objectcall(Context context, List args)
Convert the argument to a Boolean
static Booleanevaluate(Object obj, Navigator nav)

Convert the argument obj to a Boolean according to the following rules:

  • Lists are false if they're empty; true if they're not.
  • Booleans are false if they're false; true if they're true.
  • Strings are false if they're empty; true if they're not.
  • Numbers are false if they're 0 or NaN; true if they're not.
  • All other objects are true.

Constructor Detail

BooleanFunction

public BooleanFunction()
Create a new BooleanFunction object.

Method Detail

call

public Object call(Context context, List args)
Convert the argument to a Boolean

Parameters: context the context at the point in the expression when the function is called args a list with exactly one item which will be converted to a Boolean

Returns: the result of evaluating the function; Boolean.TRUE or Boolean.FALSE

Throws: FunctionCallException if args has more or less than one item

evaluate

public static Boolean evaluate(Object obj, Navigator nav)

Convert the argument obj to a Boolean according to the following rules:

Parameters: obj the object to convert to a boolean nav ignored

Returns: Boolean.TRUE or Boolean.FALSE