/*
* $Id: PresentTag.java 471754 2006-11-06 14:55:09Z husted $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.struts.taglib.logic;
import org.apache.struts.taglib.TagUtils;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import java.security.Principal;
import java.util.StringTokenizer;
/**
* Evalute the nested body content of this tag if the specified value is
* present for this request.
*
* @version $Rev: 471754 $ $Date: 2004-10-16 12:38:42 -0400 (Sat, 16 Oct 2004)
* $
*/
public class PresentTag extends ConditionalTagBase {
public static final String ROLE_DELIMITER = ",";
// ------------------------------------------------------ Protected Methods
/**
* Evaluate the condition that is being tested by this particular tag, and
* return <code>true</code> if the nested body content of this tag should
* be evaluated, or <code>false</code> if it should be skipped. This
* method must be implemented by concrete subclasses.
*
* @throws JspException if a JSP exception occurs
*/
protected boolean condition()
throws JspException {
return (condition(true));
}
/**
* Evaluate the condition that is being tested by this particular tag, and
* return <code>true</code> if the nested body content of this tag should
* be evaluated, or <code>false</code> if it should be skipped. This
* method must be implemented by concrete subclasses.
*
* @param desired Desired outcome for a true result
* @throws JspException if a JSP exception occurs
*/
protected boolean condition(boolean desired)
throws JspException {
// Evaluate the presence of the specified value
boolean present = false;
HttpServletRequest request =
(HttpServletRequest) pageContext.getRequest();
if (cookie != null) {
present = this.isCookiePresent(request);
} else if (header != null) {
String value = request.getHeader(header);
present = (value != null);
} else if (name != null) {
present = this.isBeanPresent();
} else if (parameter != null) {
String value = request.getParameter(parameter);
present = (value != null);
} else if (role != null) {
StringTokenizer st =
new StringTokenizer(role, ROLE_DELIMITER, false);
while (!present && st.hasMoreTokens()) {
present = request.isUserInRole(st.nextToken());
}
} else if (user != null) {
Principal principal = request.getUserPrincipal();
present = (principal != null) && user.equals(principal.getName());
} else {
JspException e =
new JspException(messages.getMessage("logic.selector"));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
return (present == desired);
}
/**
* Returns true if the bean given in the <code>name</code> attribute is
* found.
*
* @since Struts 1.2
*/
protected boolean isBeanPresent() {
Object value = null;
try {
if (this.property != null) {
value =
TagUtils.getInstance().lookup(pageContext, name,
this.property, scope);
} else {
value = TagUtils.getInstance().lookup(pageContext, name, scope);
}
} catch (JspException e) {
value = null;
}
return (value != null);
}
/**
* Returns true if the cookie is present in the request.
*
* @since Struts 1.2
*/
protected boolean isCookiePresent(HttpServletRequest request) {
Cookie[] cookies = request.getCookies();
if (cookies == null) {
return false;
}
for (int i = 0; i < cookies.length; i++) {
if (this.cookie.equals(cookies[i].getName())) {
return true;
}
}
return false;
}
}