org.jaxen.function

Class SubstringBeforeFunction

Implemented Interfaces:
Function

public class SubstringBeforeFunction
extends java.lang.Object
implements Function

4.2 string substring-before(string,string)
The substring-before function returns the substring of the first argument string that precedes the first occurrence of the second argument string in the first argument string, or the empty string if the first argument string does not contain the second argument string. For example, substring-before("1999/04/01","/") returns 1999.
Author:
bob mcwhirter (bob @ werken.com)
See Also:
Section 4.2 of the XPath Specification

Constructor Summary

SubstringBeforeFunction()
Create a new SubstringBeforeFunction object.

Method Summary

Object
call(Context context, List args)
Returns the part of the string-value of the first item in args that comes before the string-value of the second item in args; or the empty string if the second string is not a substring of the first string.
static String
evaluate(Object strArg, Object matchArg, Navigator nav)
Returns the part of strArg that precedes the first occurence of matchArg; or the empty string if the strArg does not contain matchArg

Constructor Details

SubstringBeforeFunction

public SubstringBeforeFunction()
Create a new SubstringBeforeFunction object.

Method Details

call

public Object call(Context context,
                   List args)
            throws FunctionCallException
Returns the part of the string-value of the first item in args that comes before the string-value of the second item in args; or the empty string if the second string is not a substring of the first string.
Specified by:
call in interface Function
Parameters:
context - the context at the point in the expression when the function is called
args - a list that contains two items
Returns:
a String containing that part of the string-value of the first item in args that comes before the string-value of the second item in args
Throws:
FunctionCallException - if args does not have length two

evaluate

public static String evaluate(Object strArg,
                              Object matchArg,
                              Navigator nav)
Returns the part of strArg that precedes the first occurence of matchArg; or the empty string if the strArg does not contain matchArg
Parameters:
strArg - the string from which the substring is extracted
matchArg - the string that marks the boundary of the substring
nav - the Navigator used to calculate the string-values of the first two arguments
Returns:
a String containing the part of strArg that precedes the first occurence of matchArg