在 AngularJS 中使用带有 Promises 的成功/错误/最终/捕获

问题描述：

我在 AngularJs 中使用 $http，但我不确定如何使用返回的承诺和处理错误.

I'm using $http in AngularJs, and I'm not sure on how to use the returned promise and to handle errors.

我有这个代码:

$http
    .get(url)
    .success(function(data) {
        // Handle data
    })
    .error(function(data, status) {
        // Handle HTTP error
    })
    .finally(function() {
        // Execute logic independent of success/error
    })
    .catch(function(error) {
        // Catch and handle exceptions from success/error/finally functions
    });

这是一个很好的方法，还是有更简单的方法?

Is this a good way to do it, or is there an easier way?

答

Promise 是对语句的抽象，允许我们用异步代码同步表达自己.它们代表一次性任务的执行.

Promises are an abstraction over statements that allow us to express ourselves synchronously with asynchronous code. They represent a execution of a one time task.

它们还提供异常处理，就像普通代码一样，您可以从承诺返回，也可以抛出.

They also provide exception handling, just like normal code, you can return from a promise or you can throw.

您想要的同步代码是:

try{
  try{
      var res = $http.getSync("url");
      res = someProcessingOf(res);
  } catch (e) {
      console.log("Got an error!",e);
      throw e; // rethrow to not marked as handled
  }
  // do more stuff with res
} catch (e){
     // handle errors in processing or in error.
}

promisified 版本非常相似:

The promisified version is very similar:

$http.get("url").
then(someProcessingOf).
catch(function(e){
   console.log("got an error in initial processing",e);
   throw e; // rethrow to not marked as handled, 
            // in $q it's better to `return $q.reject(e)` here
}).then(function(res){
    // do more stuff
}).catch(function(e){
    // handle errors in processing or in error.
});

在 AngularJS 中使用带有 Promises 的成功/错误/最终/捕获

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