org.zkoss.bind.xel.zel.PathELResolver Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of zkbind Show documentation
ZK Bind
There is a newer version: 8.6.0.1
/* PathResolver.java

	Purpose:
		
	Description:
		
	History:
		Sep 8, 2011 9:05:13 AM, Created by henrichen

Copyright (C) 2011 Potix Corporation. All Rights Reserved.
*/

package org.zkoss.bind.xel.zel;

import java.beans.FeatureDescriptor;
import java.util.Iterator;
import java.util.LinkedList;

import org.zkoss.bind.impl.Path;
import org.zkoss.lang.Objects;
import org.zkoss.zel.ELContext;
import org.zkoss.zel.ELException;
import org.zkoss.zel.ELResolver;
import org.zkoss.zel.PropertyNotFoundException;
import org.zkoss.zel.PropertyNotWritableException;
import org.zkoss.zel.impl.parser.AstIdentifier;
import org.zkoss.zel.impl.parser.Node;

/**
 * Handle dot series path when evaluating expression.
 * @author henrichen
 * @since 6.0.0
 */
public class PathELResolver extends ELResolver {
	private LinkedList _numOfKids = new LinkedList();
	private LinkedList _paths = new LinkedList();
	
	private String toNodeString(ELContext ctx) {
		final Node node0 = (Node) ctx.getContext(Node.class);
		return BindELContext.toNodeString(node0, new StringBuilder());
	}
	
	
	public Object getValue(ELContext ctx, Object base, Object property)
			throws NullPointerException, PropertyNotFoundException, ELException {
        if (ctx == null) {
            throw new NullPointerException();
        }
		Integer numOfKids;
		Path path;
        if (base == null) { //init
        	numOfKids = (Integer) ctx.getContext(AstIdentifier.class); //Number of siblings of AstIdentifier
			path = new Path();
        } else {
			numOfKids = _numOfKids.removeFirst();
			path = _paths.removeFirst();
		}

		//ZK-2808: numOfKids may be null when calling static method or class constructor
		if (numOfKids != null) {
			//maintain the number of kids
			int nums = numOfKids.intValue() - 1;
			numOfKids = new Integer(nums);
			ctx.putContext(Integer.class, numOfKids);

			//maintain the form path field
			path.add(toNodeString(ctx), Objects.toString(property));
			ctx.putContext(Path.class, path);

			if (nums > 0) { //still more property
				_numOfKids.addFirst(numOfKids);
				_paths.addFirst(path);
			}
		}
        return null;
	}

	
	public Class getType(ELContext ctx, Object base, Object property)
			throws NullPointerException, PropertyNotFoundException, ELException {
        if (ctx == null) {
            throw new NullPointerException();
        }

        // for null object with form binding
        if (!_numOfKids.isEmpty()) {
	        Integer numOfKids = _numOfKids.removeFirst();
	        Path path = _paths.removeFirst();
	        
	    	//maintain the number of kids
	    	int nums = numOfKids.intValue() - 1;
	    	numOfKids = new Integer(nums);
	    	ctx.putContext(Integer.class, numOfKids);
	
	    	//maintain the form path field
	    	path.add(toNodeString(ctx), Objects.toString(property));
	    	ctx.putContext(Path.class, path);
        }
    	return null;

	}

	
	public void setValue(ELContext ctx, Object base, Object property,
			Object value) throws NullPointerException,
			PropertyNotFoundException, PropertyNotWritableException,
			ELException {
        if (ctx == null) {
            throw new NullPointerException();
        }
		
        //#getType() will maintain number of kids and path field, just let go
	}

	
	public boolean isReadOnly(ELContext context, Object base, Object property)
			throws NullPointerException, PropertyNotFoundException, ELException {
		return true;
	}

	
	public Iterator getFeatureDescriptors(ELContext context,
			Object base) {
		return null;
	}

	
	public Class getCommonPropertyType(ELContext context, Object base) {
		return null;
	}
}