public class StringFunction extends Object implements Function
4.2 string string(object)
The string function converts an object to a string as follows:
A node-set is converted to a string by returning the string-value of the node in the node-set that is first in document order. If the node-set is empty, an empty string is returned.
A number is converted to a string as follows
NaN is converted to the string
NaN
positive zero is converted to the string
0
negative zero is converted to the string
0
positive infinity is converted to the string
Infinity
negative infinity is converted to the string
-Infinity
if the number is an integer, the number is represented in decimal form as a Number with no decimal point and no leading zeros, preceded by a minus sign (
-
) if the number is negativeotherwise, the number is represented in decimal form as a Number including a decimal point with at least one digit before the decimal point and at least one digit after the decimal point, preceded by a minus sign (
-
) if the number is negative; there must be no leading zeros before the decimal point apart possibly from the one required digit immediately before the decimal point; beyond the one required digit after the decimal point there must be as many, but only as many, more digits as are needed to uniquely distinguish the number from all other IEEE 754 numeric values.The boolean false value is converted to the string
false
. The boolean true value is converted to the stringtrue
.An object of a type other than the four basic types is converted to a string in a way that is dependent on that type.
If the argument is omitted, it defaults to a node-set with the context node as its only member.
Constructor and Description |
---|
StringFunction()
Create a new
StringFunction object. |
Modifier and Type | Method and Description |
---|---|
Object |
call(Context context,
List args)
Returns the string-value of
args.get(0)
or of the context node if args is empty. |
static String |
evaluate(Object obj,
Navigator nav)
Returns the XPath string-value of
obj . |
public Object call(Context context, List args) throws FunctionCallException
args.get(0)
or of the context node if args
is empty.call
in interface Function
context
- the context at the point in the
expression where the function is calledargs
- list with zero or one elementString
FunctionCallException
- if args
has more than one itempublic static String evaluate(Object obj, Navigator nav)
obj
.
This operation is only defined if obj is a node, node-set,
String
, Number
, or
Boolean
. For other types this function
returns the empty string.obj
- the node, node-set, string, number, or boolean
whose string-value is calculatednav
- the navigator used to calculate the string-valueString
. May be empty but is never null.Copyright 2001–2022 The Jaxen Project. All rights reserved.