net.sf.practicalxml.xpath

Class AbstractStringFunction

java.lang.Object

net.sf.practicalxml.xpath.FunctionResolver.AbstractSelfDescribingFunction

net.sf.practicalxml.xpath.AbstractStringFunction

All Implemented Interfaces:

Comparable<FunctionResolver.SelfDescribingFunction>, XPathFunction, FunctionResolver.SelfDescribingFunction

Direct Known Subclasses:

Lowercase, Uppercase, XsiBoolean

public abstract class AbstractStringFunction
extends FunctionResolver.AbstractSelfDescribingFunction

A base class for writing XPath functions that work with string data. Will convert its first argument into a string before calling evaluate(java.util.List), and provides a helper method to convert other arguments.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractStringFunction(String nsUri, String localName) Constructor for a function that takes a single argumment.
protected	AbstractStringFunction(String nsUri, String localName, int numArgs) Constructor for a function that has a fixed number of arguments.
protected	AbstractStringFunction(String nsUri, String localName, int minArgs, int maxArgs) Constructor for a function that has a variable number of arguments.

Method Summary

Methods

Modifier and Type	Method and Description
protected static String	convertToString(Object arg) Converts the passed object to a string, applying the same rules used for the built-in string() function.
Object	evaluate(List args)
abstract Object	evaluate(String value, List<?> args) Subclasses must implement this method.

Methods inherited from class net.sf.practicalxml.xpath.FunctionResolver.AbstractSelfDescribingFunction

compareTo, equals, getMaxArgCount, getMinArgCount, getName, getNamespaceUri, getQName, hashCode, isArityMatch, isMatch

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractStringFunction

protected AbstractStringFunction(String nsUri,
                      String localName)

Constructor for a function that takes a single argumment.

AbstractStringFunction

protected AbstractStringFunction(String nsUri,
                      String localName,
                      int numArgs)

Constructor for a function that has a fixed number of arguments.

AbstractStringFunction

protected AbstractStringFunction(String nsUri,
                      String localName,
                      int minArgs,
                      int maxArgs)

Constructor for a function that has a variable number of arguments.

Method Detail

evaluate

public final Object evaluate(List args)
                      throws XPathFunctionException

Throws:

XPathFunctionException

evaluate

public abstract Object evaluate(String value,
              List<?> args)

Subclasses must implement this method. It is passed the first argument already converted to a string, as well as the original list of arguments.

convertToString

protected static String convertToString(Object arg)

Converts the passed object to a string, applying the same rules used for the built-in string() function.