content: /*
   * Text.java April 2007
   *
   * Copyright (C) 2007, Niall Gallagher <niallg@users.sf.net>
   *
   * Licensed 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.
   */
  
  package com.aliyun.odps.simpleframework.xml;
  
  import com.aliyun.odps.simpleframework.xml.transform.Transformer;
  import java.lang.annotation.RetentionPolicy;
  import java.lang.annotation.Retention;
  
  /**
   * The <code>Text</code> annotation is used to represent a field or
   * method that appears as text within an XML element. Methods and
   * fields annotated with this must represent primitive values, which
   * means that the type is converted to and from an XML representation
   * using a <code>Transform</code> object. For example, the primitive 
   * types typically annotated could be strings, integers, or dates.  
   * <p>
   * One restriction on this annotation is that it can only appear once 
   * within a schema class, and it can not appear with the another XML 
   * element annotations, such as the <code>Element</code> annotation. 
   * It can however appear with any number of <code>Attribute</code> 
   * annotations.
   * <pre>
   * 
   *    &lt;example one="value" two="value"&gt;
   *       Example text value       
   *    &lt;/example&gt;
   * 
   * </pre>
   * Text values are used when an element containing attributes is
   * used to wrap a text value with no child elements. This can be
   * used in place of an element annotation to represent a primitive
   * which is wrapped in a surrounding XML element.
   * 
   * @author Niall Gallagher
   * 
   * @see Transformer
   */ 
  @Retention(RetentionPolicy.RUNTIME)
  public @interface Text {
     
     /**
      * This is used to provide a default value for the text data if
      * the annotated field or method is null. This ensures the the
      * serialization process writes the text data with a value even
      * if the value is null, and allows deserialization to determine
      * whether the value within the object was null or not.
      * 
      * @return this returns the default attribute value to use
      */
     String empty() default "";
     
     /**
      * This is used to determine whether the text is written within 
      * CDATA block or not. If this is set to true then the text is
      * written within a CDATA block, by default the text is output
      * as escaped XML. Typically this is used for large text values.
      * 
      * @return true if the data is to be wrapped in a CDATA block
      */
     boolean data() default false;
     
     /**
      * Determines whether the text value is required within the XML
      * document. Any field marked as not required may not have its
      * value set when the object is deserialized. If an object is to
      * be serialized only a null attribute will not appear in XML.
      * 
      * @return true if the element is required, false otherwise
      */
     boolean required() default true; 
  }