我需要AngularJS $ http服务还是什么的两个实例？ [英] I need two instances of AngularJS $http service or what?

问题描述

我要响应拦截器添加到我的$ http服务的错误处理的目的。拦截器逻辑包括在必要的情况下使用$ HTTP发送错误信息到服务器，的但的我不想发送错误消息有关错误邮件的服务器，我的意思是，我想禁用我的拦截器在发送错误消息给服务器

I want add a response interceptor to my $http service for error handling purposes. The interceptor logic include send errors messages to server using $http in case necessary, BUT I don't want send errors messages to the server about errors messages, I mean, I want disable my interceptor while sending error message to the server.

我的想法是创建一个名为remote_log，并把它里面的所有发送错误到服务器所需的code服务。当然，这服务将使用$ HTTP服务，有它在的依赖列表中。

My idea was create a service named 'remote_log' and put inside it all the code needed to send error to server. That service of course will use the $http service and have it in its dependency list.

然后添加为拦截到remote_log服务的依赖，并且需要将错误发送到服务器时使用了remote_log拦截器内。的问题之一是：

Then add as dependency of the interceptor to the 'remote_log' service, and use the 'remote_log' inside the interceptor when need send errors to the server. The problems is that:

拦截器必须使用被定义的$ httpProvider当$ HTTP服务仍无法实例化/访问，因此，拦截器code里面不能成为一种依赖，将$ HTTP服务，因为一个循环依赖错误发生。

Interceptors must be defined using the $httpProvider when the $http service still is not instantiated/accessible, so, inside the interceptor code can't be a dependency to that the $http service because a "Circular dependency" error happen.

我想我唯一的选择就是创建我的'remote_log'，不使用$ httpProvider配置，同时创造了拦截我设置一个实例里面的$ http服务的一个单独的实例。我的问题是：我怎样才能做到这一点？任何其他的想法？

I think my only option is create a separate instance of the $http service inside my 'remote_log', an instance that don't uses the $httpProvider configuration I set while creating the interceptor. My question is: How can I do that? Any other ideas?

推荐答案

那么，为什么会出现错误？下面是该过程的简要概述：

1. Circular dependency problem.

So, why does the error appear? Here is a quick overview of the process:

1. $ HTTP服务请求。


2. $ httpProvider被要求来构建它。


3. 在施工过程中您注册拦截器，请求$ http服务不存在呢。


4. 您获得循环依赖的错误。

创建您的使用依赖angular.injector（）。请注意，你将创造另一个$ http服务，独立于您的应用程序。

Create your dependency using angular.injector(). Notice, that you will create another $http service, independent from your app.

$httpProvider.interceptors.push(function($q) {
    $injector = angular.injector();
    return {
        response: function(response): {
            $injector.invoke(function($http) { 
                // This is the exterior $http service!
                // This interceptor will not affect it.
            }
        }
    };
});

$注入注射器在你的拦截器，并使用它$ HTTP初始化后检索的依赖，就在你需要他们的时候。这些依赖注册您的应用程序的服务，并不会重新建立！

Inject $injector in your interceptor and use it to retrieve dependencies after $http initialization, right at the time you need them. These dependencies are registered services of your app and will not be created anew!

$httpProvider.interceptors.push(function($q, $injector) {
    return {
        response: function(response): {
            $injector.invoke(function($http, someService) {
                // $http is already constructed at the time and you may
                // use it, just as any other service registered in your
                // app module and modules on which app depends on.
            }
        }
    };
});

如果你使用第二个解决方案，实际上有两个问题：

If you use the second solution, there are actually two problems:

1. 如果您使用在$ http服务的
   拦截器，你可能最终与无限的拦截：你送
   请求拦截器捕获它，发送另一个，另一个捕捉，
   再次发送，等等。


2. 有时候，你只想prevent请求被截取。

$ HTTP服务的'配置'参数只是一个对象。您可以创建一个惯例，提供自定义参数，并在你的拦截器识别它们。

The 'config' parameter of $http service is just an object. You may create a convention, providing custom parameters and recognizing them in your interceptors.

例如，让我们添加nointercept属性来配置，并尝试复制每个用户的请求。这是一个愚蠢的申请，但有用的例子来理解的行为：

For example, let's add "nointercept" property to config and try duplicate every user request. This is a silly application, but useful example to understand the behavior:

$httpProvider.interceptors.push(function($q, $injector) {
    return {
        response: function(response): {
            if (response.config.nointercept) {
                return $q.when(response); // let it pass
            } else {
                var defer = $q.defer();
                $injector.invoke(function($http) {
                    // This modification prevents interception:
                    response.config.nointercept = true;
                    // Reuse modified config and send the same request again:
                    $http(response.config)
                        .then(function(resp) { defer.resolve(resp); },
                              function(resp) { defer.reject(resp); });
                }
                return defer.promise;
            }
        }
    };
});

具有拦截财产的测试，您可能prevent在控制器和服务截取：

Having the testing for property in interceptor, you may prevent the interception in controllers and services:

app.controller('myController', function($http) {
    // The second parameter is actually 'config', see API docs.
    // This query will not be duplicated by the interceptor.
    $http.get('/foo/bar', {nointercept: true})
        .success(function(data) {
            // ...
        });

});

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