我用两个实体管理器实现了存储库模式,mainManager 用于只读和删除,updateManager 用于编辑和添加新实体。我使用 createEmptyCopy() 创建 updateManager。
在我更新实体之前,我从 mainManager 导出实体并导入到 updateManager,在更改之后我调用 updateManager.saveChanges() 方法。
我注意到我在承诺响应中取回了更新的实体。我想知道将这些实体导入 mainManager 的最佳做法是什么?
这是我的代码:
function ($q, $http, entityManagerFactory) {
var self = this;
self.mainManager = entityManagerFactory.newManager();
self.updateManager = entityManagerFactory.newManager();
self.saveChanges = function () {
return self.updateManager.saveChanges();
};
self.rejectChanges = function() {
self.updateManager.rejectChanges();
};
self.getDomains = function () {
self.mainManager.clear();
var query = new breeze.EntityQuery()
.from('Domains')
.orderBy('name');
return self.mainManager.executeQuery(query);
};
self.createEmptyDomain = function () {
var domain = self.updateManager.createEntity('Domain');
return domain;
};
self.editDomain = function(domain) {
var exported = self.mainManager.exportEntities([domain]);
return self.updateManager.importEntities(exported).entities[0];
}
self.addDomain = function (domain) {
self.updateManager.addEntity(domain);
return self.updateManager.saveChanges();
};
self.deleteDomain = function (domain) {
domain.entityAspect.setDeleted();
var deferred = $q.defer();
self.mainManager.saveChanges().then(
function(data) {
deferred.resolve(data);
},
function (reason) {
console.log(reason);
self.mainManager.rejectChanges();
deferred.reject(reason);
});
return deferred.promise;
};
}
现在我正在调用 mainManager.clear() 并再次从服务器获取数据,正如您在上面的 getDomains 函数中看到的那样。但我认为这太过分了,如果我已经拥有 saveChanges 承诺中的更新实体,为什么还要调用服务器?
我还尝试使用以下方法将这些实体导入回 mainManager:
mainManager.importEntities(data.entities, { mergeStrategy: breeze.MergeStrategy.OverwriteChanges });
但我得到一个内部空微风异常:
TypeError: Cannot read property 'forEach' of undefined
at EntityManager.proto.importEntities (breeze.debug.js:13081)
at self.importEntities (domain-list.service.js:22)
at domain-list.controller.js:70
at processQueue (angular.js:13170)
at angular.js:13186
at Scope.promises.$get.Scope.$eval (angular.js:14383)
at Scope.promises.$get.Scope.$digest (angular.js:14199)
at Scope.promises.$get.Scope.$apply (angular.js:14488)
at done (angular.js:9646)
at completeRequest (angular.js:9836)
错误来自这一行微风.debug.js:13081
13080: var tempKeyMap = {};
13081: json.tempKeys.forEach(function (k) {
13082: var oldKey = EntityKey.fromJSON(k, that.metadataStore);
13083: // try to use oldKey if not already used in this keyGenerator. 13084: tempKeyMap[oldKey.toString()] = new EntityKey(oldKey.entityType,
13085: that.keyGenerator.generateTempKeyValue(oldKey.entityType, oldKey.values[0]));
13086: });