在$ http拦截器中重新调用$ http请求

Question

So I am intercepting an angular $http request and response. Lets say that if I had a response error, I want to reinvoke my $http call. The issue is that I need to inject $http service into my interceptor and it creates a circular dependency. This is the simplified version of my code in coffeescript:

retryModule = angular.module('retry-call', [])

retryModule.factory 'RetryCall', ($q, $http)->
  # More object keys
  'responseError': (response)=>
    # Retry request if failed
    # I need a different way of invoking $http() to avoid circular dependency
    $http(response.config)
    $q.reject(response)

retryModule.config ['$httpProvider', ($httpProvider)->
    $httpProvider.interceptors.push('RetryCall');
]

Thanks

Answer 1

To avoid the circular dependency you could always just decorate the $http service to handle this functionality. Here is an example of a decorator.

You would basically do something like this pseudocode:

var old_post = $delegate.post;
$delegate.post = function(post_stuff) {
    var def = $q.defer();
    old_post(post_stuff).then(function(data) {
        if (data.error) {
            $delegate.post(post_stuff).then(function(data) {
                 def.resolve(data);
            }
        } else {
            def.resolve(data)
        }
    }, function(err_data) {
        // Also retry here
    });
};
return $delegate;

This basically wraps the original $http call in your retry functionality. The code is untested as it's just a basic idea of how to do it. Also you should be careful, since this could create an infinite loop.

Hope this helps!

Answer 2

After reviewing the Angular source code the better answer is such. $http method is accessible without dependency injection so the trick is to NOT INJECT $http and to simply use it. Like such:

Right Way

retryModule = angular.module('retry-call', [])

# Do not inject $http
retryModule.factory 'RetryCall', ($q)->
  # More object keys
  'responseError': (response)=>
    # Just use $http without injecting it
    $http(response.config)
    $q.reject(response)

retryModule.config ['$httpProvider', ($httpProvider)->
    $httpProvider.interceptors.push('RetryCall');
]

Wrong Way

# Do not do it this way.
retryModule.factory 'RetryCall', ($q,$http)->