cvs commit: cocoon-2.1/src/blocks/forms/java/org/apache/cocoon/forms/datatype/convertor ConversionResult.java

[bruno]

bruno       2004/05/06 08:12:13

  Added:       src/blocks/forms/java/org/apache/cocoon/forms/datatype/convertor
                        ConversionResult.java
  Log:
  Made Convertor.convertFromString contract more solid by letting it
  return a ConversionResult object (instead of null/not-null to indicate
  successful conversion). This also moves the responsibility
  of creating the ValidationError to the Convertor, allowing convertors
  to set more specialised messages in them.
  
  Revision  Changes    Path
  1.1                  
cocoon-2.1/src/blocks/forms/java/org/apache/cocoon/forms/datatype/convertor/ConversionResult.java
  
  Index: ConversionResult.java
  ===================================================================
  /*
   * Copyright 1999-2004 The Apache Software Foundation.
   *
   * 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 org.apache.cocoon.forms.datatype.convertor;
  
  import org.apache.cocoon.forms.validation.ValidationError;
  import org.apache.cocoon.forms.util.I18nMessage;
  import org.apache.cocoon.forms.Constants;
  
  /**
   * Object returned as result of [EMAIL PROTECTED] 
Convertor#convertFromString(java.lang.String, java.util.Locale, 
org.apache.cocoon.forms.datatype.convertor.Convertor.FormatCache)}.
   */
  public class ConversionResult {
      private ValidationError validationError;
      private boolean successful;
      private Object result;
  
      /**
       * Constructs a successful ConversionResult.
       */
      public ConversionResult(Object result) {
          this.successful = true;
          this.result = result;
      }
  
      /**
       * Constructs an unsuccessful ConversionResult.
       */
      public ConversionResult(ValidationError validationError) {
          this.successful = false;
          this.validationError = validationError;
      }
  
      /**
       * Constructs an unsuccessful ConversionResult. Will create
       * a default ValidationError message using the given
       * datatypeName.
       *
       * <p>Note: this is not done as a constructor because
       * it would conflict with the constructor which takes
       * an Object as argument.
       */
      public static ConversionResult create(String datatypeName) {
          ValidationError validationError = new ValidationError(new I18nMessage(
              "datatype.conversion-failed",
              new String[] {"datatype." + datatypeName},
              new boolean[] { true },
              Constants.I18N_CATALOGUE
          ));
          return new ConversionResult(validationError);
      }
  
      public boolean isSuccessful() {
          return successful;
      }
  
      public ValidationError getValidationError() {
          if (successful)
              throw new IllegalStateException("Cannot call getValidationError() 
if conversion is successful.");
  
          return validationError;
      }
  
      public Object getResult() {
          if (!successful)
              throw new IllegalStateException("Cannot call getResult() if 
conversion is not successful.");
  
          return result;
      }
  }