Angular.js和ng-switch-when-emulating枚举 [英] Angular.js and ng-switch-when - emulating enum

问题描述

我想在某些类型的安全性中为我的控制器逻辑引入一些枚举，所以例如我创建了一些这样的东西：

I wanted to introduce some enum to my controller logic for some type safety, so for example I created something like this:

var app = angular.module('myApp', []);
var StateEnum = Object.freeze({"login":1, "logout":2})
function LoginCheckCtrl($scope) {
    $scope.stateEnum = StateEnum
    $scope.loginData = StateEnum.login
    $scope.login = function() {
        console.log($scope.loginData  ? 'logged in' : 'not logged in');
        $scope.loginData = StateEnum.logout;
    };
    $scope.logout = function() {
        console.log($scope.loginData ? 'logged in' : 'not logged in');
        $scope.loginData = StateEnum.login;
    };
}

在我的示例页面中，我会有这样的：

and in my example page I would have something like this:

<div ng-controller="LoginCheckCtrl">
   <div ng-switch on="loginData"> 
      <div ng-switch-when="stateEnum.login" ng-include="'login'"></div>
      <div ng-switch-when="stateEnum.logout" ng-include="'logout'"></div>
   </div>
</div>

<script type="text/ng-template" id="login">
    <button ng-click="login()">Login</button>
</script>

<script type="text/ng-template" id="logout">
    <button ng-click="logout()">Logout</button>
</script>

但 ng-switch-when 想工作只有当我用 ng-swith-when 手动替换整数时的值，例如1,2。

but ng-switch-when does not want to work. It only works if I substitute values in ng-swith-when manually with integers, for example 1,2.

以下是演示文稿的小费：

Here are fiddles to demonstrate this:

http： //jsfiddle.net/jNxyE/3/

http://jsfiddle.net/4Jg7M/2/

现在，你可以看到，第一个显然不起作用，第二个工作 - 意思是当按钮被点击时，它会改变按钮。

now, as you can see, the first one clearly does not work, and second one works - meaning it changes button when button is clicked.

我认为的问题是这个 var StateEnum = Object.freeze（{登录：1，注销：2}）。

是否可以在我的html中使用我的枚举，所以 ng-switch-when 将正常工作（如第二个小提琴）？

Is is possible to use my enum in my html so ng-switch-when will work properly (as in second fiddle)?

推荐答案

认为我会创建一个可以拥有所有枚举的服务：

I think I would create a service that could have all your enums:

angular.module('Enums', []).
   factory('Enum', [ function () {

      var service = {
        freeze: {login:1, logout:2 },
          somethingelse: {abc:1,def:2}
      };

     return service;

    }]);

您的应用定义如下：

var app = angular.module('myApp', ['Enums']);

然后您的控制器可以在需要时注入它们：

Then your controllers you could inject them when you need them:

function LoginCheckCtrl($scope, Enum) {
    if (1==Enum.freeze.login) // as an example
    if (1==Enum.somethingelse.abc)  // another example

服务是单身，所以这样会有效地你可以定义一组枚举。

Services are singletons so this effectively will give you a set of enums you could define.

对于指令中的ngSwitch，我相信它需要一个字符串（如果我错了，请更正我）。一对夫妇参考：

As for the ngSwitch when directive, I believe it requires a string (please correct me if I'm wrong). A couple references:

https：/ /groups.google.com/forum/?fromgroups#!topic/angular/EH4W0y93ZAA
https://github.com/angular/angular.js/blob/master/src/ng/directive/ngSwitch.js#L171

另一种实现想要的方法是使用 ng-show / ng-hide

An alternate way to achieve what you want would be to use ng-show/ng-hide

<div ng-include="'login'" ng-show='stateEnum.login==loginData' ...>

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