MessagesPresentTag xref

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    1   /*
    2    * $Id: MessagesPresentTag.java 471754 2006-11-06 14:55:09Z husted $
    3    *
    4    * Licensed to the Apache Software Foundation (ASF) under one
    5    * or more contributor license agreements.  See the NOTICE file
    6    * distributed with this work for additional information
    7    * regarding copyright ownership.  The ASF licenses this file
    8    * to you under the Apache License, Version 2.0 (the
    9    * "License"); you may not use this file except in compliance
    10   * with the License.  You may obtain a copy of the License at
    11   *
    12   *  http://www.apache.org/licenses/LICENSE-2.0
    13   *
    14   * Unless required by applicable law or agreed to in writing,
    15   * software distributed under the License is distributed on an
    16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    17   * KIND, either express or implied.  See the License for the
    18   * specific language governing permissions and limitations
    19   * under the License.
    20   */
    21  package org.apache.struts.taglib.logic;
    22
    23  import org.apache.struts.Globals;
    24  import org.apache.struts.action.ActionMessages;
    25  import org.apache.struts.taglib.TagUtils;
    26
    27  import javax.servlet.jsp.JspException;
    28
    29  import java.util.Iterator;
    30
    31  /**
    32   * Evalute to <code>true</code> if an <code>ActionMessages</code> class or a
    33   * class that can be converted to an <code>ActionMessages</code> class is in
    34   * request scope under the specified key and there is at least one message in
    35   * the class or for the property specified.
    36   *
    37   * @version $Rev: 471754 $ $Date: 2005-11-19 12:36:20 -0500 (Sat, 19 Nov 2005)
    38   *          $
    39   * @since Struts 1.1
    40   */
    41  public class MessagesPresentTag extends ConditionalTagBase {
    42      /**
    43       * If this is set to 'true', then the <code>Globals.MESSAGE_KEY</code>
    44       * will be used to retrieve the messages from scope.
    45       */
    46      protected String message = null;
    47
    48      public MessagesPresentTag() {
    49          name = Globals.ERROR_KEY;
    50      }
    51
    52      public String getMessage() {
    53          return (this.message);
    54      }
    55
    56      public void setMessage(String message) {
    57          this.message = message;
    58      }
    59
    60      /**
    61       * Evaluate the condition that is being tested by this particular tag, and
    62       * return <code>true</code> if the nested body content of this tag should
    63       * be evaluated, or <code>false</code> if it should be skipped.
    64       *
    65       * @throws JspException if a JSP exception occurs
    66       */
    67      protected boolean condition()
    68          throws JspException {
    69          return (condition(true));
    70      }
    71
    72      /**
    73       * Evaluate the condition that is being tested by this particular tag, and
    74       * return <code>true</code> if there is at least one message in the class
    75       * or for the property specified.
    76       *
    77       * @param desired Desired outcome for a true result
    78       * @throws JspException if a JSP exception occurs
    79       */
    80      protected boolean condition(boolean desired)
    81          throws JspException {
    82          ActionMessages am = null;
    83
    84          String key = name;
    85
    86          if ((message != null) && "true".equalsIgnoreCase(message)) {
    87              key = Globals.MESSAGE_KEY;
    88          }
    89
    90          try {
    91              am = TagUtils.getInstance().getActionMessages(pageContext, key);
    92          } catch (JspException e) {
    93              TagUtils.getInstance().saveException(pageContext, e);
    94              throw e;
    95          }
    96
    97          Iterator iterator = (property == null) ? am.get() : am.get(property);
    98
    99          return (iterator.hasNext() == desired);
    100     }
    101
    102     /**
    103      * Release all allocated resources.
    104      */
    105     public void release() {
    106         super.release();
    107         name = Globals.ERROR_KEY;
    108         message = null;
    109     }
    110 }