src/web/org/codehaus/groovy/grails/web/taglib/GroovyDefTag.java

   1 /* Copyright 2004-2005 the original author or authors.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at
   6  *
   7  *      http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 package org.codehaus.groovy.grails.web.taglib;
  16
  17 import org.apache.commons.lang.StringUtils;
  18 import org.codehaus.groovy.grails.web.taglib.exceptions.GrailsTagException;
  19 import grails.util.GrailsUtil;
  20
  21 /**
  22  * Allows defining of variables within the page context
  23  *
  24  * @author Graeme Rocher
  25  * @since 23-Feb-2006
  26  */
  27 public class GroovyDefTag extends GroovySyntaxTag {
  28     public static final String TAG_NAME = "def";
  29     private static final String ATTRIBUTE_VALUE = "value";
  30     public void doStartTag() {
  31         String expr = (String) attributes.get(ATTRIBUTE_VALUE);
  32         String var = (String) attributes.get(ATTRIBUTE_VAR);
  33
  34         if(StringUtils.isBlank(var))
  35             throw new GrailsTagException("Tag ["+TAG_NAME+"] missing required attribute ["+ATTRIBUTE_VAR+"]");
  36         if(StringUtils.isBlank(expr))
  37             throw new GrailsTagException("Tag ["+TAG_NAME+"] missing required attribute ["+ATTRIBUTE_VALUE +"]");
  38
  39         GrailsUtil.deprecated("The tag <g:def> is deprecated and will be removed in a future release. Use <g:set> instead.");
  40         out.print("def ");
  41         out.print(var.substring(1,var.length() -1));
  42         out.print('=');
  43         out.println(expr);
  44     }
  45
  46     public void doEndTag() {
  47         // do nothing
  48     }
  49
  50     public String getName() {
  51         return TAG_NAME;
  52     }
  53
  54     public boolean isBufferWhiteSpace() {
  55         return false;
  56     }
  57
  58     public boolean hasPrecedingContent() {
  59         return true;
  60     }
  61 }