Validator.java

/*
 * Copyright (C) 2011 Google Inc.
 *
 * 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.google.api.explorer.client.editors;

import java.util.List;

/**
 * Represents a validator that will check if the value(s) of a parameter are
 * valid based on some criteria.
 *
 * @author jasonhall@google.com (Jason Hall)
 */
public interface Validator {

  /**
   * A single result that encapsulates the results of validation.
   */
  public interface ValidationResult {
    /**
     * A descriptive type for a validation result.
     */
    public enum Type {
      VALID, INFO, ERROR
    }

    /**
     * Returns which type of validation result this is.
     */
    Type getType();

    /**
     * Returns a message associated with the result, if the result type is not
     * VALID.
     */
    String getMessage();
  }

  /**
   * Returns true if all the values for this {@link Editor} are valid based on
   * this validator's requirements.
   */
  ValidationResult isValid(List<String> value);
}