package de.toi.bot.cbs.wsp.admin.util;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.opensymphony.xwork.ActionInvocation;
import com.opensymphony.xwork.interceptor.AroundInterceptor;

/**
 * interceptor tweaking boolean parameters. parameters with names 
 * starting by PREFIX will be stripped of it, and if no value is available under 
 * stripped name explicitely set to false. 
 * 
 * this helps to overcome problem with boolean checkboxes ( unchecked value is not sent 
 * by browser ) 
 * @author k.pribluda
 *
 */
public class BooleanTweaker extends AroundInterceptor {
	public final static String PREFIX = "_FALSE_.";
	public final static String FALSE = "false";
	private static final Log LOG = LogFactory.getLog(BooleanTweaker.class);

	protected void after(ActionInvocation arg0, String arg1) throws Exception {
	
	}

	protected void before(ActionInvocation ai) throws Exception {
		final Map parameters = ai.getInvocationContext().getParameters();
		
		String key;
		Map toSet = new HashMap();
		for(Iterator iter = parameters.keySet().iterator(); iter.hasNext();) {
			key = iter.next().toString();
			if(key.startsWith(PREFIX)) {
				key = key.substring(PREFIX.length());
				if(!parameters.containsKey(key)) {
					toSet.put(key,FALSE);
				}
			}
		}
		parameters.putAll(toSet);
	}

}