radiotag.java

一个实用工具类

/*
 * Copyright (C) butor.com. All rights reserved.
 *
 * This software is published under the terms of the GNU Library General
 * Public License (GNU LGPL), a copy of which has been included with this
 * distribution in the LICENSE.txt file. 
 */


package org.butor.web.taglib.html;

import java.lang.reflect.InvocationTargetException;

import javax.servlet.jsp.JspException;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.struts.util.RequestUtils;
import org.apache.struts.util.ResponseUtils;
import org.butor.web.action.IButorActionForm;

/**
 * @author nacroaz
 *
 * To change this generated comment edit the template variable "typecomment":
 * Window>Preferences>Java>Templates.
 */
public class RadioTag extends org.apache.struts.taglib.html.RadioTag {
	
    /**
     * Generate the required input tag.
     * [Indexed property since 1.1]
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {
	   	// Find and check the form bean	  
    	Object o = RequestUtils.lookup(pageContext, name, null);    	
        if (! (o instanceof IButorActionForm)) {
			ResponseUtils.write(pageContext, "The form bean must be an instance of ButorActionForm !!!");  
			return SKIP_BODY;
        }        
        IButorActionForm form = (IButorActionForm) o;
        
        // If property is enable, use super class definition 
        if (form.getEnabled(property)) {
        	return super.doStartTag();
        } else {        
        	// the property is disable, we must render it properly         	        	
	        // Acquire the current value of the appropriate field
    	    Object current = null;
        	Object bean = pageContext.findAttribute(name);
	        if (bean == null){	        	
    	        throw new JspException(messages.getMessage("getter.bean", name));
	        }
                		
	        try {
    	        current = BeanUtils.getProperty(bean, property);
        	    if (current == null) {
            	    current = "";
        	    }
            } catch (IllegalAccessException e) {
                throw new JspException(messages.getMessage("getter.access", property, name));
            } catch (InvocationTargetException e) {
                Throwable t = e.getTargetException();
                throw new JspException(messages.getMessage("getter.result", property, t.toString()));
	        } catch (NoSuchMethodException e) {
    	        throw new JspException(messages.getMessage("getter.method", property, name));
	        }              		

            // If current value match the tag value, then render this property as checked
			if (current.equals(value)) {        	  
				//  Add the checked image
				TagLibHelper.renderText(pageContext, "<img src=\"/_images/radio_on.gif\">", false);
	            
				// Add an hidden field for this property
				TagLibHelper.renderHiddenField(pageContext, property, current.toString());	
			} else {
				//  Add the checked image
				TagLibHelper.renderText(pageContext, "<img src=\"/_images/radio_off.gif\">", false);
			}
        }
        
        this.text = null;
        return EVAL_BODY_BUFFERED;
    }    
}