formtag.java

sun公司的petstore,一个J2ee的示例应用程序.

/*
 * Copyright 2002 Sun Microsystems, Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistribution 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.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN
 * OR ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR
 * FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR
 * PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF
 * LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that Software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of
 * any nuclear facility.
 */

package com.sun.j2ee.blueprints.waf.view.taglibs.smart;

import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.tagext.BodyTagSupport;
import javax.servlet.jsp.tagext.BodyContent;

import java.io.IOException;
import java.util.*;

/**
 * A smart form.
 */
public class FormTag extends BodyTagSupport {

    Map validatedFields = new TreeMap();
    String name;
    String action;
    String method;
    String formHTML;

    public void putValidatedField(String fieldName, String fieldType) {
        validatedFields.put(fieldName, fieldType);
    }

    public void setName(String n) { name = n; }

    public void setAction(String a) { action = a; }

    public void setMethod(String m) { method = m; }

    public int doStartTag() throws JspTagException {
        return EVAL_BODY_BUFFERED;
    }

    public int doAfterBody() throws JspTagException {
        BodyContent bc = getBodyContent();
        formHTML = bc.getString();
        bc.clearBody();
        return SKIP_BODY;
    }

    public int doEndTag() throws JspTagException {
        try {
            StringBuffer html = new StringBuffer();
            StringBuffer javaScript = new StringBuffer();

            javaScript.append("<script language=\"JavaScript\">\n");
            javaScript.append("function validate_" + name +"() {\n");
            javaScript.append("    var ret = true;\n");
            for (Iterator it = validatedFields.keySet().iterator();
                 it.hasNext(); ) {
                String fieldName = (String) it.next();
                String fieldType = (String) validatedFields.get(fieldName);
                javaScript.append("    if (window.document.");
                javaScript.append(name + ".");
                javaScript.append(fieldName + ".");
                javaScript.append("value");
                javaScript.append(" ==");
                javaScript.append(" \"\"");
                javaScript.append(") {\n");
                javaScript.append("        alert(\"" + fieldName
                                  + " is empty.\");\n");
                javaScript.append("        ret = false;\n");
                javaScript.append("    }\n");
            }
            javaScript.append("    return ret;\n");
            javaScript.append("}\n");
            javaScript.append("</script>\n");

            html.append("<form");
            html.append(" name=\"" + name +"\"");
            html.append(" action=\"" + action + "\"");
            html.append(" method=\"" + method + "\"");
            html.append(" onSubmit=\"return validate_" + name + "();\"");
            html.append(">\n");
            html.append(formHTML);
            html.append("</form>");
            pageContext.getOut().print(javaScript.toString());
            pageContext.getOut().print(html.toString());
            return EVAL_PAGE;
        }
        catch (IOException e) {
            throw new JspTagException("FormTag: " + e.getMessage());
        }
    }
}