text: /*****************************************************************************
   * Open MCT Web, Copyright (c) 2014-2015, United States Government
   * as represented by the Administrator of the National Aeronautics and Space
   * Administration. All rights reserved.
   *
   * Open MCT Web is 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.
   *
   * Open MCT Web includes source code licensed under additional open source
   * licenses. See the Open Source Licenses file (LICENSES.md) included with
   * this source code distribution or the Licensing information page available
   * at runtime from the About dialog for additional information.
   *****************************************************************************/
  
  define(
      [],
      function () {
  
          /**
           * Handles actual persistence invocations for queeud persistence
           * attempts, in a group. Handling in a group in this manner
           * also allows failure to be handled in a group (e.g. in a single
           * summary dialog.)
           * @param $q Angular's $q, for promises
           * @param {PersistenceFailureHandler} handler to invoke in the event
           *        that a persistence attempt fails.
           * @constructor
           * @memberof platform/persistence/queue
           */
          function PersistenceQueueHandler($q, failureHandler) {
              this.$q = $q;
              this.failureHandler = failureHandler;
          }
  
          /**
           * Invoke the persist method on the provided persistence
           * capabilities.
           * @param {Object.<string,PersistenceCapability>} persistences
           *        capabilities to invoke, in id->capability pairs.
           * @param {Object.<string,DomainObject>} domainObjects
           *        associated domain objects, in id->object pairs.
           * @param {PersistenceQueue} queue the persistence queue,
           *        to requeue as necessary
           * @memberof platform/persistence/queue.PersistenceQueueHandler#
           */
          PersistenceQueueHandler.prototype.persist = function (persistences, domainObjects, queue) {
              var ids = Object.keys(persistences),
                  $q = this.$q,
                  failureHandler = this.failureHandler;
  
              // Handle a group of persistence invocations
              function persistGroup(ids, persistences, domainObjects, queue) {
                  var failures = [];
  
                  // Try to persist a specific domain object
                  function tryPersist(id) {
                      // Look up its persistence capability from the provided
                      // id->persistence object.
                      var persistence = persistences[id],
                          domainObject = domainObjects[id];
  
                      // Put a domain object back in the queue
                      // (e.g. after Overwrite)
                      function requeue() {
                          return queue.put(domainObject, persistence);
                      }
  
                      // Handle success
                      function succeed(value) {
                          return value;
                      }
  
                      // Handle failure (build up a list of failures)
                      function fail(error) {
                          failures.push({
                              id: id,
                              persistence: persistence,
                              domainObject: domainObject,
                              requeue: requeue,
                              error: error
                          });
                          return false;
                      }
  
                      // Invoke the actual persistence capability, then
                      // note success or failures
                      return persistence.persist().then(succeed, fail);
                  }
  
                  // Handle any failures from the full operation
                  function handleFailure(value) {
                      return failures.length > 0 ?
                          failureHandler.handle(failures) :
                          value;
                  }
  
                  // Try to persist everything, then handle any failures
                  return $q.all(ids.map(tryPersist)).then(handleFailure);
              }
  
              return persistGroup(ids, persistences, domainObjects, queue);
          };
  
          return PersistenceQueueHandler;
      }
  );
  