2009/05/20 - Apache Shale has been retired.

 /*

  * 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.

  */

 /*

  * $Id: ClayTagValidator.java 464373 2006-10-16 04:21:54Z rahul $

  */

 package org.apache.shale.clay.taglib;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.ArrayList;

 import java.util.List;

 import javax.servlet.jsp.tagext.PageData;

 import javax.servlet.jsp.tagext.TagLibraryValidator;

 import javax.servlet.jsp.tagext.ValidationMessage;

 import org.apache.shale.clay.parser.Node;

 import org.apache.shale.clay.parser.Parser;

 import org.apache.shale.util.Messages;

 /**

  * <p>Validates the JSP page for the clay namespace,

  * "http://shale.apache.org/shale/clay-plugin".  This tag

  * validator checks to make sure that there are not any nested

  * tags under the {@link ClayTag} with the exception of the

  * {@link SymbolTag}.</p>

  */

 public class ClayTagValidator extends TagLibraryValidator {

     /**

      * <p>URI Namespace for the clay tag lib.</p>

      */

     private static final String CLAY_URI_NAMESPACE = "http://shale.apache.org/clay";

     /**

      * <p>Message resources for this class.</p>

      */

     private static Messages messages = new Messages("org.apache.shale.clay.Bundle",

             ClayTagValidator.class.getClassLoader());

     /**

      * <p>Loads the <code>page</code> content into a <code>StringBuffer</code>.</p>

      *

      * @param page tag page data

      * @return document in a string buffer

      * @exception IOException error reading page data

      */

     protected StringBuffer loadTemplate(PageData page) throws IOException {

         StringBuffer buff = new StringBuffer();

         InputStream inputStream = page.getInputStream();

             int c = 0;

             done: while (true) {

                 c = inputStream.read();

                 if (c > -1) {

                     buff.append((char) c);

                 } else {

                     break done;

                 }

             }

             return buff;

     }

     /**

      * <p>Creates a <code>ValidationMessage</code> for a {@link ClayTag} containing

      * a child of anything other than the {@link SymbolTag}.</p>

      *

      * @param prefix qname

      * @param clayNode markup

      * @param childNode child markup

      *

      * @return message for the JSP compiler

      */

     private ValidationMessage getMessage(String prefix, Node clayNode, Node childNode) {

        Object[] args = {clayNode.getToken().getRawText(),

                         childNode.getToken().getRawText(),

                         prefix};

        String jspid = (String) childNode.getAttributes().get("jsp:id");

        String message = messages.getMessage("invalid.nested.tag", args);

        return new ValidationMessage(jspid, message);

     }

     /**

      * <p>Checks the child nodes of the <code>clayNode</code> verifying that

      * only the symbol node is present.</p>

      *

      * @param prefix qname

      * @param clayNode markup

      * @param messages error messages

      */

     private void checkForInvalidNestedTags(String prefix, Node clayNode, List messages) {

         List children = clayNode.getChildren();

         next: for (int i = 0; i < children.size(); i++) {

             Node child = (Node) children.get(i);

             if ((!child.isComment() && !child.isCdata()) && child.isWellFormed()) {

                 if (child.getQname() != null && child.getName() != null) {

                     if (child.getQname().equals("jsp") && child.getName().equals("text")) {

                         continue next;

                     }  else if (!child.getName().equals("symbol") || !prefix.equals(child.getQname())) {

                         messages.add(getMessage(prefix, clayNode, child));

                     }

                 }

             }

         }

     }

     /**

      * <p>Recursively walks the parsed document looking for clay component nodes.  The children

      * are checked to make sure the symbol tag is the only valid child tag.</p>

      *

      * @param prefix qname

      * @param node markup

      * @param messages list of errors

      */

     private void validateClayTags(String prefix, Node node, List messages) {

        if ((!node.isComment() && !node.isCdata()) && node.isWellFormed()

            && node.getName() != null && node.getName().equals("clay")

            && node.getQname() != null && node.getQname().equals(prefix)) {

            checkForInvalidNestedTags(prefix, node, messages);

            return;

        }

        List children = node.getChildren();

        for (int i = 0; i < children.size(); i++) {

           Node child = (Node) children.get(i);

           validateClayTags(prefix, child, messages);

        }

     }

     /**

      * <p>Validates the page for a directive with a uri of

      * "<strong>http://shale.apache.org/shale/clay-plugin</strong>".

      *

      * @param prefix namespace

      * @param uri namespace

      * @param page normalized jsp page into XML

      * @return error messages

      */

     public ValidationMessage[] validate(String prefix, String uri, PageData page) {

         List messages = new ArrayList();

         if (uri != null && CLAY_URI_NAMESPACE.equals(uri)) {

             try {

                 StringBuffer buff = loadTemplate(page);

                 Parser p = new Parser();

                 List roots = p.parse(buff);

                 for (int i = 0;  i < roots.size(); i++) {

                     Node node = (Node) roots.get(i);

                     validateClayTags(prefix, node, messages);

                 }

             } catch (IOException e) {

                 messages.add(new ValidationMessage(null, e.getMessage()));

             }

         }

         if (messages.isEmpty()) {

             return null;

         } else {

             ValidationMessage[] validationMessages = new ValidationMessage[messages.size()];

             messages.toArray(validationMessages);

             return validationMessages;

         }

     }

 }