1 /**
2 * This file Copyright (c) 2003-2010 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.cms.taglibs.util;
35
36 import info.magnolia.cms.beans.config.ServerConfiguration;
37 import info.magnolia.cms.core.Content;
38 import info.magnolia.cms.security.Permission;
39 import info.magnolia.context.MgnlContext;
40 import org.apache.commons.lang.StringUtils;
41 import org.slf4j.Logger;
42 import org.slf4j.LoggerFactory;
43
44 import javax.servlet.http.HttpServletRequest;
45 import javax.servlet.http.HttpServletResponse;
46 import javax.servlet.jsp.JspException;
47 import javax.servlet.jsp.tagext.BodyTagSupport;
48 import javax.servlet.jsp.tagext.Tag;
49 import java.io.IOException;
50 import java.util.Iterator;
51
52
53 /**
54 * Redirects to the first child page. If the server is an authoring instance or magnolia and the preview mode is not
55 * active the tag will simply add to the pagecontext a variable named from the <code>var</code> attribute containing
56 * the path of the child page.
57 * <p>
58 * A typical requirement is to have pages with no content which will simply redirect to a child page: using this tag you
59 * can easily build a "redirect" template and use it for empty pages:
60 * </p>
61 *
62 * <pre>
63 * Title Template Mod. Date
64 * -----------------------^----------------^-------^----------------------^---------------
65 * - siteroot - o redirect 05-01-01
66 * - it - o redirect 05-01-01
67 * + home Home page o home 05-01-01
68 *
69 * </pre>
70 *
71 * <p>
72 * This tag should be put <strong>before</strong> any other tag or include in the page, since response should not be
73 * committed yet for it to work.
74 * </p>
75 * <p>
76 * Example:
77 * </p>
78 *
79 * <pre>
80 * <cmsu:redirect var="destpage" />
81 *
82 * This page has no content and it will redirect to
83 * <a href="${pageContext.request.contextPath}${destpage}">${destpage}</a> in a public instance.
84 * </pre>
85 *
86 * @jsp.tag name="redirect" body-content="empty"
87 * @jsp.tag-example
88 * <cmsu:redirect var="destpage" />
89 * This page has no content and it will redirect to
90 * <a href="${pageContext.request.contextPath}${destpage}">${destpage}</a> in a public instance.
91 *
92 * @author Fabrizio Giustina
93 * @version $Id: RedirectTag.java 32667 2010-03-13 00:37:06Z gjoseph $
94 * @since 2.2
95 */
96 public class RedirectTag extends BodyTagSupport {
97
98 /**
99 * Stable serialVersionUID.
100 */
101 private static final long serialVersionUID = 222L;
102
103 /**
104 * Logger.
105 */
106 private static Logger log = LoggerFactory.getLogger(RedirectTag.class);
107
108 private String var;
109
110 /**
111 * Name for the variable which will contain the URL of the page this tag will redirect to.
112 * @jsp.attribute required="false" rtexprvalue="true"
113 */
114 public void setVar(String var) {
115 this.var = var;
116 }
117
118 /**
119 * @see javax.servlet.jsp.tagext.Tag#doStartTag()
120 */
121 public int doStartTag() throws JspException {
122 HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
123 String location = getRedirectLocation(request);
124
125 Content activePage = MgnlContext.getAggregationState().getMainContent();
126
127 // on public servers, during preview or when the user can't edit the page, just send the redirect
128 if (!ServerConfiguration.getInstance().isAdmin() || MgnlContext.getAggregationState().isPreviewMode() || !activePage.isGranted(Permission.SET)) {
129 if (location != null) {
130 try {
131 ((HttpServletResponse) pageContext.getResponse()).sendRedirect(request.getContextPath() + location);
132 }
133 catch (IOException e) {
134 log.error("Could not redirect to first child HTML page: " + e.getMessage()); //$NON-NLS-1$
135 }
136 return Tag.SKIP_PAGE;
137 }
138 }
139 else if (StringUtils.isNotBlank(var)) {
140 request.setAttribute(var, location);
141 }
142 return super.doStartTag();
143 }
144
145 /**
146 * @see javax.servlet.jsp.tagext.Tag#release()
147 */
148 public void release() {
149 this.var = null;
150 super.release();
151 }
152
153 /**
154 * Returns the locationto which we intend to redirect.
155 * @param request The HTTP request.
156 * @return A URI if a child page is available, or null.
157 */
158 private String getRedirectLocation(HttpServletRequest request) {
159 Content page = MgnlContext.getAggregationState().getMainContent();
160 Iterator it = page.getChildren().iterator();
161 if (it.hasNext()) {
162 Content c = (Content) it.next();
163 return c.getHandle() + '.' + ServerConfiguration.getInstance().getDefaultExtension();
164 }
165
166 return null;
167 }
168
169 }