radiotag.java

这是一个轻便的j2ee的web应用框架,是一个在多个项目中运用的实际框架,采用struts,hebinate,xml等技术,有丰富的tag,role,navigation,session,dictio

/*
 * $Header: /sfroot/cvs/esimple/src/core/com/esimple/framework/web/taglib/html/RadioTag.java,v 1.1.1.1 2004/09/08 06:38:19 lava Exp $
 * $Revision: 1.1.1.1 $
 * $Date: 2004/09/08 06:38:19 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Struts", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package com.esimple.framework.web.taglib.html;

import javax.servlet.jsp.JspException;

import org.apache.struts.util.MessageResources;
import org.apache.struts.util.ResponseUtils;

/**
 * Tag for input fields of type "radio".
 *
 * @author Craig R. McClanahan
 * @author Ted Husted
 * @author David Graham
 * @version $Revision: 1.1.1.1 $ $Date: 2004/09/08 06:38:19 $
 */
public class RadioTag extends BaseHandlerTag {


    // ----------------------------------------------------- Instance Variables


    /**
     * The message resources for this package.
     */
    protected static MessageResources messages =
     MessageResources.getMessageResources(Constants.Package + ".LocalStrings");


    /**
     * The name of the bean containing our underlying property.
     */
    protected String name = Constants.BEAN_KEY;

    public String getName() {
        return (this.name);
    }

    public void setName(String name) {
        this.name = name;
    }


    /**
     * The property name for this field.
     */
    protected String property = null;


    /**
     * The body content of this tag (if any).
     */
    protected String text = null;


    /**
     * The server value for this option.
     */
    protected String value = null;


    /**
     * Name of the bean (in some scope) that will return the
     * value of the radio tag.
     * <p>
     * If an iterator is used to render a series of radio tags,
     * this field may be used to specify the name of the bean
     * exposed by the iterator. In this case, the value attribute is
     * used as the name of a property on the <code>idName</code> bean
     * that returns the value of the radio tag in this iteration.
     */
    protected String idName = null;


    // ------------------------------------------------------------- Properties


    /**
     * Return the property name.
     */
    public String getProperty() {

        return (this.property);

    }

    /**
     * Set the property name.
     *
     * @param property The new property name
     */
    public void setProperty(String property) {

        this.property = property;

    }

    /**
     * Return the server value.
     */
    public String getValue() {

        return (this.value);

    }

    /**
     * Set the server value.
     *
     * @param value The new server value
     */
    public void setValue(String value) {

        this.value = value;

    }

    /**
     * Return the idName.
     * @since Struts 1.1
     */
    public String getIdName() {

        return (this.idName);

    }

    /**
     * Set the idName.
     * @since Struts 1.1
     *
     * @param idName The new idName
     */
    public void setIdName(String idName) {

        this.idName=idName;

    }


    // --------------------------------------------------------- Public Methods


    /**
     * Generate the required input tag.
     * [Indexed property since Struts 1.1]
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {

        String radioTag = renderRadioElement(serverValue(), currentValue());

        ResponseUtils.write(pageContext, radioTag);

        this.text = null;
        return (EVAL_BODY_TAG);
    }

    /**
     * Return the String to be used in the radio tag's <code>value</code> attribute 
     * that gets sent to the server on form submission.
     * @throws JspException
     */
    private String serverValue() throws JspException {

        // Not using indexed radio buttons
        if (this.idName == null) {
            return this.value;
        }
        
        String serverValue = this.lookupProperty(this.idName, this.value);
        
        return (serverValue == null) ? "" : serverValue;
    }

    /**
     * Acquire the current value of the bean specified by the <code>name</code> 
     * attribute and the property specified by the <code>property</code> attribute.
     * This radio button with this value will be checked.
     * @throws JspException
     */
    private String currentValue() throws JspException {
        String current = this.lookupProperty(this.name, this.property);
        
        return (current == null) ? "" : current;
    }
    
    /**
     * Renders an HTML &lt;input type="radio"&gt; element.
     * @param serverValue The data to be used in the tag's <code>value</code> 
     * attribute and sent to the server when the form is submitted.
     * @param checkedValue If the serverValue equals this value the radio button 
     * will be checked.
     * @return A radio input element.
     * @throws JspException
     * @since Struts 1.1
     */
    protected String renderRadioElement(String serverValue, String checkedValue)
        throws JspException {
            
        StringBuffer results = new StringBuffer("<input type=\"radio\"");
        results.append(" name=\"");
        // @since Struts 1.1
        if (indexed) {
            prepareIndex(results, name);
        }
        results.append(this.property);
        results.append("\"");
        if (accesskey != null) {
            results.append(" accesskey=\"");
            results.append(accesskey);
            results.append("\"");
        }
        if (tabindex != null) {
            results.append(" tabindex=\"");
            results.append(tabindex);
            results.append("\"");
        }
        results.append(" value=\"");
        results.append(serverValue);
        results.append("\"");
        if (serverValue.equals(checkedValue)) {
            results.append(" checked=\"checked\"");
        }
        results.append(prepareEventHandlers());
        results.append(prepareStyles());
        results.append(getElementClose());
        return results.toString();
    }

    /**
     * Save the associated label from the body content.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doAfterBody() throws JspException {

        if (this.bodyContent != null) {
            String value = this.bodyContent.getString().trim();
            if (value.length() > 0) {
                this.text = value;
            }
        }
        
        return (SKIP_BODY);
    }

    /**
     * Optionally render the associated label from the body content.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doEndTag() throws JspException {

        // Render any description for this radio button
        if (this.text != null) {
            ResponseUtils.write(pageContext, text);
        }
        
        return (EVAL_PAGE);

    }

    /**
     * Release any acquired resources.
     */
    public void release() {

        super.release();
        name = Constants.BEAN_KEY;
        property = null;
        text = null;
        value = null;

    }

}