org.zkoss.zk.ui.metainfo.FunctionMapperInfo Maven / Gradle / Ivy
/* FunctionMapperInfo.java
Purpose:
Description:
History:
Mon May 5 14:41:03 2008, Created by tomyeh
Copyright (C) 2008 Potix Corporation. All Rights Reserved.
{{IS_RIGHT
This program is distributed under LGPL Version 2.1 in the hope that
it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.ui.metainfo;
import java.util.Map;
import org.zkoss.lang.Classes;
import org.zkoss.xel.FunctionMapper;
import org.zkoss.zk.ui.Page;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.xel.Evaluator;
import org.zkoss.zk.xel.ExValue;
/**
* A definition of the function mapper ({@link FunctionMapper}).
*
* Note: we resolve the class by using Classes.forNameByThread.
* In other words, it doesn't support the class defined in zscript.
* Why not? Since there is no way to run zscript before the function-mapper
* directive (and better performance).
*
* Note: it is not serializable.
* @author tomyeh
* @since 3.5.0
*/
public class FunctionMapperInfo extends ArgumentInfo { //directive
/** A class, an ExValue or an FunctionMapper. */
private Object _mapper;
/** Constructs with a class.
* @param args the map of arguments. Ignored if null.
* Notice that, once assigned, the map belongs to this object, and the caller
* shall not access it again
* @since 3.6.1
*/
public FunctionMapperInfo(Class cls, Map args) {
super(args);
checkClass(cls);
_mapper = cls;
}
/** Constructs with a class.
*/
public FunctionMapperInfo(Class cls) {
this(cls, null);
}
private static void checkClass(Class cls) {
if (!FunctionMapper.class.isAssignableFrom(cls))
throw new UiException(FunctionMapper.class + " must be implemented: " + cls);
}
/** Constructs with a class name.
*
* @param clsnm the class name; it could be an EL expression.
*/
public FunctionMapperInfo(String clsnm, Map args) throws ClassNotFoundException {
super(args);
if (clsnm == null || clsnm.length() == 0)
throw new IllegalArgumentException("empty");
if (clsnm.indexOf("${") < 0) {
if (clsnm.indexOf('.') >= 0) { //resolve it now
try {
final Class cls = Classes.forNameByThread(clsnm);
checkClass(cls);
_mapper = cls;
} catch (ClassNotFoundException ex) {
throw new ClassNotFoundException("Class not found: " + clsnm, ex);
}
} else { //it might depend on
_mapper = clsnm;
}
} else {
_mapper = new ExValue(clsnm, String.class);
}
}
/** Constructs with a class name.
*
* @param clsnm the class name; it could be an EL expression.
*/
public FunctionMapperInfo(String clsnm) throws ClassNotFoundException {
this(clsnm, null);
}
/** Constructs with an initiator that will be reuse each time
* {@link #newFunctionMapper} is called.
*/
public FunctionMapperInfo(FunctionMapper mapper) {
super(null);
if (mapper == null)
throw new IllegalArgumentException("null");
_mapper = mapper;
}
/** Creates and returns the function mapper for the specified pagedefinition and page.
*/
public FunctionMapper newFunctionMapper(PageDefinition pgdef, Page page) throws Exception {
return newFunctionMapper(pgdef.getEvaluator(), page);
}
/** Creates and returns the function mapper for the specified evaluator and page.
* @since 3.6.2
*/
public FunctionMapper newFunctionMapper(Evaluator eval, Page page) throws Exception {
if (_mapper instanceof FunctionMapper)
return (FunctionMapper) _mapper;
String clsnm = null;
if (_mapper instanceof ExValue) {
clsnm = (String) ((ExValue) _mapper).getValue(eval, page);
if (clsnm == null || clsnm.length() == 0) {
return null; //ignore it!!
}
} else if (_mapper instanceof String) {
clsnm = (String) _mapper;
}
final Class cls;
if (clsnm != null) {
try {
cls = page != null ? page.resolveClass(clsnm) : Classes.forNameByThread(clsnm);
checkClass(cls);
} catch (ClassNotFoundException ex) {
throw new ClassNotFoundException("Class not found: " + clsnm + " (" + _mapper + ")", ex);
}
if (clsnm.equals(_mapper))
_mapper = cls; //cache it for better performance
} else {
cls = (Class) _mapper;
}
return (FunctionMapper) newInstance(cls, eval, page);
}
//Object//
public String toString() {
return "[function-mapper " + _mapper + "]";
}
}