/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
*
* Portions Copyright Apache Software Foundation.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can obtain
* a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
* or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
* Sun designates this particular file as subject to the "Classpath" exception
* as provided by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the License
* Header, with the fields enclosed by brackets [] replaced by your own
* identifying information: "Portions Copyrighted [year]
* [name of copyright owner]"
*
* Contributor(s):
*
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package org.apache.taglibs.standard.tlv;
import java.util.Set;
import java.util.Stack;
import javax.servlet.jsp.tagext.PageData;
import javax.servlet.jsp.tagext.ValidationMessage;
import org.apache.taglibs.standard.resources.Resources;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;
/**
* <p>A SAX-based TagLibraryValidator for the JSTL i18n-capable formatting
* library. Currently implements the following checks:</p>
*
* <ul>
* <li>Expression syntax validation.
* <li>Tag bodies that must either be empty or non-empty given
* particular attributes.</li>
* </ul>
*
* @author Shawn Bayern
* @author Jan Luehe
*/
public class JstlFmtTLV extends JstlBaseTLV {
//*********************************************************************
// Implementation Overview
/*
* We essentially just run the page through a SAX parser, handling
* the callbacks that interest us. We collapse <jsp:text> elements
* into the text they contain, since this simplifies processing
* somewhat. Even a quick glance at the implementation shows its
* necessary, tree-oriented nature: multiple Stacks, an understanding
* of 'depth', and so on all are important as we recover necessary
* state upon each callback. This TLV demonstrates various techniques,
* from the general "how do I use a SAX parser for a TLV?" to
* "how do I read my init parameters and then validate?" But also,
* the specific SAX methodology was kept as general as possible to
* allow for experimentation and flexibility.
*
* Much of the code and structure is duplicated from JstlCoreTLV.
* An effort has been made to re-use code where unambiguously useful.
* However, splitting logic among parent/child classes isn't
* necessarily the cleanest approach when writing a parser like the
* one we need. I'd like to reorganize this somewhat, but it's not
* a priority.
*/
//*********************************************************************
// Constants
// tag names
private final String SETLOCALE = "setLocale";
private final String SETBUNDLE = "setBundle";
private final String SETTIMEZONE = "setTimeZone";
private final String BUNDLE = "bundle";
private final String MESSAGE = "message";
private final String MESSAGE_PARAM = "param";
private final String FORMAT_NUMBER = "formatNumber";
private final String PARSE_NUMBER = "parseNumber";
private final String PARSE_DATE = "parseDate";
// private final String EXPLANG = "expressionLanguage";
private final String JSP_TEXT = "jsp:text";
// attribute names
private final String EVAL = "evaluator";
private final String MESSAGE_KEY = "key";
private final String BUNDLE_PREFIX = "prefix";
private final String VALUE = "value";
//*********************************************************************
// set its type and delegate validation to super-class
public ValidationMessage[] validate(
String prefix, String uri, PageData page) {
return super.validate( TYPE_FMT, prefix, uri, page );
}
//*********************************************************************
// Contract fulfillment
protected DefaultHandler getHandler() {
return new Handler();
}
//*********************************************************************
// SAX event handler
/** The handler that provides the base of our implementation. */
private class Handler extends DefaultHandler {
// parser state
private int depth = 0;
private Stack messageDepths = new Stack();
private String lastElementName = null;
private boolean bodyNecessary = false;
private boolean bodyIllegal = false;
// process under the existing context (state), then modify it
public void startElement(
String ns, String ln, String qn, Attributes a) {
// substitute our own parsed 'ln' if it's not provided
if (ln == null)
ln = getLocalPart(qn);
// for simplicity, we can ignore <jsp:text> for our purposes
// (don't bother distinguishing between it and its characters)
if (qn.equals(JSP_TEXT))
return;
// check body-related constraint
if (bodyIllegal)
fail(Resources.getMessage("TLV_ILLEGAL_BODY",
lastElementName));
// validate expression syntax if we need to
Set expAtts;
if (qn.startsWith(prefix + ":")
&& (expAtts = (Set) config.get(ln)) != null) {
for (int i = 0; i < a.getLength(); i++) {
String attName = a.getLocalName(i);
if (expAtts.contains(attName)) {
String vMsg =
validateExpression(
ln,
attName,
a.getValue(i));
if (vMsg != null)
fail(vMsg);
}
}
}
// validate attributes
if (qn.startsWith(prefix + ":") && !hasNoInvalidScope(a))
fail(Resources.getMessage("TLV_INVALID_ATTRIBUTE",
SCOPE, qn, a.getValue(SCOPE)));
if (qn.startsWith(prefix + ":") && hasEmptyVar(a))
fail(Resources.getMessage("TLV_EMPTY_VAR", qn));
if (qn.startsWith(prefix + ":")
&& !isFmtTag(ns, ln, SETLOCALE)
&& !isFmtTag(ns, ln, SETBUNDLE)
&& !isFmtTag(ns, ln, SETTIMEZONE)
&& hasDanglingScope(a))
fail(Resources.getMessage("TLV_DANGLING_SCOPE", qn));
/*
* Make sure <fmt:param> is nested inside <fmt:message>. Note that
* <fmt:param> does not need to be a direct child of <fmt:message>.
* Otherwise, the following would not work:
*
* <fmt:message key="..." bundle="...">
* <c:forEach var="arg" items="...">
* <fmt:param value="${arg}"/>
* </c:forEach>
* </fmt:message>
*/
if (isFmtTag(ns, ln, MESSAGE_PARAM) && messageDepths.empty()) {
fail(Resources.getMessage("PARAM_OUTSIDE_MESSAGE"));
}
// now, modify state
// If we're in a <message>, record relevant state
if (isFmtTag(ns, ln, MESSAGE)) {
messageDepths.push(Integer.valueOf(depth));
}
// set up a check against illegal attribute/body combinations
bodyIllegal = false;
bodyNecessary = false;
if (isFmtTag(ns, ln, MESSAGE_PARAM)
|| isFmtTag(ns, ln, FORMAT_NUMBER)
|| isFmtTag(ns, ln, PARSE_NUMBER)
|| isFmtTag(ns, ln, PARSE_DATE)) {
if (hasAttribute(a, VALUE))
bodyIllegal = true;
else
bodyNecessary = true;
} else if (isFmtTag(ns, ln, MESSAGE)
&& !hasAttribute(a, MESSAGE_KEY)) {
bodyNecessary = true;
} else if (isFmtTag(ns, ln, BUNDLE)
&& hasAttribute(a, BUNDLE_PREFIX)) {
bodyNecessary = true;
}
// record the most recent tag (for error reporting)
lastElementName = qn;
lastElementId = a.getValue(JSP, "id");
// we're a new element, so increase depth
depth++;
}
public void characters(char[] ch, int start, int length) {
bodyNecessary = false; // body is no longer necessary!
// ignore strings that are just whitespace
String s = new String(ch, start, length).trim();
if (s.equals(""))
return;
// check and update body-related constraints
if (bodyIllegal)
fail(Resources.getMessage("TLV_ILLEGAL_BODY",
lastElementName));
}
public void endElement(String ns, String ln, String qn) {
// consistently, we ignore JSP_TEXT
if (qn.equals(JSP_TEXT))
return;
// handle body-related invariant
if (bodyNecessary)
fail(Resources.getMessage("TLV_MISSING_BODY",
lastElementName));
bodyIllegal = false; // reset: we've left the tag
// update <message>-related state
if (isFmtTag(ns, ln, MESSAGE)) {
messageDepths.pop();
}
// update our depth
depth--;
}
}
}
|
