Angular $http:在“超时"配置上设置承诺 [英] Angular $http : setting a promise on the 'timeout' config

问题描述

在 Angular $http 文档中，它提到你可以将超时"配置设置为数字或承诺.

In the Angular $http docs, it mentions that you can set the 'timeout' config to either a number or a promise.

timeout – {number|Promise} – 以毫秒为单位的超时，或承诺解决后应中止请求.

timeout – {number|Promise} – timeout in milliseconds, or promise that should abort the request when resolved.

但我不确定如何使用承诺来完成这项工作.我如何设置一个数字和一个承诺?基本上，我希望能够知道 http 调用(承诺)是否由于超时"或其他原因而出错.我需要能够分辨出差异.感谢您的帮助！！！

But I am not sure how to make this work using a promise. how do i set a number and a promise ? Basically I want to be able to know whether an http call (promise) errored due to a 'timeout' or something else. I need to be able to tell the difference. Thanks for any help !!!

推荐答案

此代码来自 $httpBackend 源代码:

if (timeout > 0) {
  var timeoutId = $browserDefer(timeoutRequest, timeout);
} else if (timeout && timeout.then) {
  timeout.then(timeoutRequest);
}

function timeoutRequest() {
  status = ABORTED;
  jsonpDone && jsonpDone();
  xhr && xhr.abort();
}

timeout.then(timeoutRequest) 表示当promise被解析(不是拒绝)timeoutRequest被调用，xhr请求被中止.

timeout.then(timeoutRequest) means that when the promise is resolved (not rejected) timeoutRequest is invoked and xhr request is aborted.

如果请求超时，则reject.status === 0(注意:在网络故障的情况下，reject.status 也将是等于 0)，示例:

If the request was timeout then reject.status === 0 (Note: in case of a network failure, then reject.status will also be equals to 0), An example:

app.run(function($http, $q, $timeout){

  var deferred = $q.defer();

  $http.get('/path/to/api', { timeout: deferred.promise })
    .then(function(){
      // success handler
    },function(reject){
      // error handler            
      if(reject.status === 0) {
         // $http timeout
      } else {
         // response error status from server 
      }
    });

  $timeout(function() {
    deferred.resolve(); // this aborts the request!
  }, 1000);
});

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