我的 AngularJS CRUD 应用程序通过 WebSocket 服务器处理它的信息。（这主要是为了让一个用户的更新自动推送给所有用户，而不需要大量的 HTTP 轮询）
我很早就意识到，我必须以不同于通常使用 HTTP 服务的方式设置我的服务。通常，对于我正在使用的每个模型，我都会为他们提供自己的服务来填充该特定模型。但是，这对于 Websocket 连接是不可行的，因为我不希望每个服务都有单独的连接。因此，有几个解决方案。
1）设置一个建立连接的服务，然后与将使用该服务进行特定查询的其他服务共享该连接
2）创建一个单一的、类型不可知的服务，所有需要访问连接和数据的控制器都将使用该服务。
选项 2 似乎更容易管理，并且可以跨应用程序重用，所以我开始了。那时我意识到这实际上是一个机会。我可以创建一个主对象，并在数据从请求流入时根据需要data动态创建子对象，而不是为客户端可以接收的每种类型的数据显式创建模型。myService.data因此，如果我需要更新我的模型，我只需在服务器级别更新模型，客户端已经知道如何接收它；它只需要一个知道如何使用它的控制器。
然而，这个机会带来了一个缺点。显然，因为myService.Data在创建时是一个空的、无子对象，任何想要引用其未来子对象的 Scope 都必须简单地引用对象本身。
例如，$scope.user = myService.data.user 抛出一个错误，因为该对象在声明时不存在。看来我唯一的选择是让每个控制器简单地拥有$scope.data = myservice.data，并且每个控制器的视图都必须使用
< ng-model='data'>，声明类似于{{data.user.username}}。我已经测试过了，这确实有效。
我的问题是这个；有什么方法可以让我两全其美？我可以让我的服务动态更新它的数据模型，但仍然让我的控制器只访问他们需要的部分吗？一世？直到我意识到我的所有控制器都可以访问整个数据模型之前，我感觉自己很聪明……但老实说，我无法确定这是否是一个大问题。
这是我的服务：
app.factory('WebSocketService', ['$rootScope', function ($rootScope) {
var factory = {
socket: null,
data: {},
startConnection: function () {
//initialize Websocket
socket = new WebSocket('ws://localhost:2012/')
socket.onopen = function () {
//todo: Does anything need to happen OnOpen?
}
socket.onclose = function () {
//todo: Does anything need to happen OnClose?
}
socket.onmessage = function (event) {
var packet = JSON.parse(event.data);
////Model of Packet:
////packet.Data: A serialised Object that contains the needed data
////packet.Operation: What to do with the Data
////packet.Model: which child object of Factory.data to use
////packet.Property: used by Update and Delete to find a specific object with a property who's name matches this string, and who's value matches Packet.data
//Deserialize Data
packet.Data = JSON.parse(packet.Data);
//"Refresh" is used to completely reload the array
// of objects being stored in factory.data[packet.Model]
// Used for GetAll commands and manual user refreshes
if (packet.Operation == "Refresh") {
factory.data[packet.Model] = packet.Data
}
//Push is used to Add an object to an existing array of objects.
//The server will send this after somebody sends a successful POST command to the WebSocket Server
if (packet.Operation == "Push") {
factory.data[packet.Model].push(packet.Data)
}
if (packet.Operation == "Splice") {
for (var i = 0; i < factory.data[packet.Model].length; i++) {
for (var j = 0; j < packet.Data.length; j++){
if (factory.data[packet.Model][i][packet.Property] == packet.Data[j][packet.Property]) {
factory.data[packet.Model].splice(i, 1);
i--;
}
}
}
}
// Used to update existing objects within the Array. Packet.Data will be an array, although in most cases it will usually only have one value.
if (packet.Operation == "Update") {
for (var i = 0; i < factory.data[packet.Model].length; i++) {
for (var j = 0; j < packet.Data.length; j++) {
if (factory.data[packet.Model][i][packet.Property] == packet.Data[j][packet.Property]) {
factory.data[packet.Model][i] = packet.Data[j]
i--;
}
}
}
}
//Sent by WebSocket Server after it has properly authenticated the user, sending the user information that it has found.
if (packet.Operation == "Authentication") {
if (packet.Data == null) {
//todo: Authentication Failed. Alert User Somehow
}
else {
factory.data.user = packet.Data;
factory.data.isAuthenticated = true;
}
}
$rootScope.$digest();
}
},
stopConnection: function () {
if (socket) {
socket.close();
}
},
//sends a serialised command to the Websocket Server according to it's API.
//The DataObject must be serialised as a string before it can be placed into Packet object,which will also be serialised.
//This is because the Backend Framework is C#, which must see what Controller and Operation to use before it knows how to properly Deserialise the DataObject.
sendPacket: function (Controller, Operation, DataObject) {
if (typeof Controller == "string" && typeof Operation == "string") {
var Data = JSON.stringify(DataObject);
var Packet = { Controller: Controller, Operation: Operation, Data: Data };
var PacketString = JSON.stringify(Packet);
socket.send(PacketString);
}
}
}
return factory
}]);
这是一个访问用户信息的简单控制器。它实际上用在<div>Index.html 中的永久标题中，在动态之外<ng-view>。它负责启动 Websocket 连接。
App.controller("AuthenticationController", function ($scope, WebSocketService) {
init();
function init() {
WebSocketService.startConnection();
}
//this is the ONLY way that I have found to access the Service Data.
//$scope.user = WebSocketService.data.user doesn't work
//$scope.user = $scope.data.user doesn't even work
$scope.data = WebSocketService.data
});
这是使用该控制器的 HTML
<div data-ng-controller="AuthenticationController">
<span data-ng-model="data">{{data.user.userName}}</span>
</div>