TokenFormatter.java

/*
 * Copyright 2012 Cedric Hauber
 *
 *    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.jboss.errai.mvp.client.places;

import java.util.List;

/**
 * Formats tokens from {@code String} values to {@link PlaceRequest} and {@link PlaceRequest}
 * hierarchies and vice-versa. An implementation is provided in {@link ParameterTokenFormatter}, see
 * the documentation of this class for details.
 */
public interface TokenFormatter {

  /**
   * Converts a place request hierarchy (a list of {@link PlaceRequest}) into a history token. The
   * history token will not be fully query encoded, it may still contain some unescaped separators.
   * However, these separators can be encoded and it will still work, making the scheme robust to
   * systems that force encoding these characters like some email apps.
   *
   * @param placeRequestHierarchy The place request hierarchy.
   * @return The history token, URL encoded.
   * @throws TokenFormatException if there is an error converting.
   */
  String toHistoryToken(List<PlaceRequest> placeRequestHierarchy)
      throws TokenFormatException;

  /**
   * Converts a place token into a {@link PlaceRequest}. A place token is different than a history
   * token, since the history token can contain a hierarchy of different place requests.
   *
   * @param placeToken The place token.
   * @return The place request.
   * @throws TokenFormatException if there is an error converting.
   */
  PlaceRequest toPlaceRequest(String placeToken) throws TokenFormatException;

  /**
   * Converts a history token into a place request hierarchy (a list of {@link PlaceRequest}).
   *
   * @param historyToken The history token.
   * @return The place request hierarchy.
   * @throws TokenFormatException if there is an error converting.
   */
  List<PlaceRequest> toPlaceRequestHierarchy(String historyToken)
      throws TokenFormatException;

  /**
   * Converts a {@link PlaceRequest} into a place token. A place token is different than a history
   * token, since the history token can contain a hierarchy of different place requests. The history
   * token will not be fully query encoded, it may still contain some unescaped separators.
   * However, these separators can be encoded and it will still work, making the scheme robust to
   * systems that force encoding these characters like some email apps.
   *
   * @param placeRequest The place request.
   * @return The place token, URL encoded.
   * @throws TokenFormatException if there is an error converting.
   */
  String toPlaceToken(PlaceRequest placeRequest) throws TokenFormatException;

}