鏈2 HTTP請求並返回第二個承諾

Question

在發出HTTP請求之前，我需要檢查我擁有的訪問憑證是否有效。如果它們無效，我需要發出第一個HTTP請求來重新驗證它們，然後在完成之後再發出第二個HTTP請求（原始請求）。函數調用需要從第二個HTTP請求返回Angular的$http承諾。這裏是我的功能：

var makeRequest = function (scope, address, request, basic, form) { 

     startLoad(scope); 

     // Check if user is logged in and needs a new session token... 
     if (ready() && (now() > getSessionExpires()-20)) { 

      // Setup auth.session.refresh request 
      var refreshRequest = { 
       "refreshToken": getRefreshToken(), 
       "clientID": getClientID(), 
      }; 

      // Make auth.session.refresh request 
      $http.post(API + 'auth.session.refresh', format(refreshRequest)) 
       .error(function (data) { 
        // If refresh request fails, logout and redirect to expired message 
        stopLoad(scope); logoff(); 
        $window.location.href = '/error/expired'; 
        return; 
       }) 
       .success(function (data) { 
        // If refresh request succeeds, makeRequest is called recursively and the else condition runs 
        process(data, true); 
        return makeRequest(scope, address, request, basic, form); 
       }); 

     } else { // if not logged in, or if session token is valid, run request function as usual 

      // Add Authorization header with valid sessionToken 
      if (ready()) $http.defaults.headers.post['Authorization'] = 'Bearer ' + getSessionToken(); 

      // Basic Request: returns promise (if next context not set, can chain other action) 
      if (basic) { 
       return $http.post(API + address, request) 
        .error(function(data) { 

         if (data && scope) stopLoad(scope, data.message); 
         else if (scope) stopLoad(scope, Defaults.serverError); 
         else stopLoad(); 

         if (form) resetForm(form); 
        }) 
        .success(function(data) { 
         process(data); 

         if (scope) { 
          stopLoad(scope); 
          if (scope.context.next) $location.path(scope.context.next); 
         } else stopLoad(); 

         if (form) resetForm(form); 
        }); 
      } 

      // Custom Request: returns promise (can chain .error, .success) 
      else return $http.post(API + address, request); 
     } 
    }; 

當令牌被發現是無效的，但是，該函數返回undefined，我感到我不能運行.success（）錯誤或.error（）。其他功能運行，但我想知道如何確保我不會得到這個錯誤。謝謝！

Answer 1

只返回上$http.post(/*...*/)，讓承諾鏈接做它的神奇：

return $http.post(API + 'auth.session.refresh', format(refreshRequest)) 
        .catch(function (response) { 
         // If refresh request fails, logout and redirect to expired message 
         stopLoad(scope); logoff(); 
         $window.location.href = '/error/expired'; 
        }) 
        .then(function (response) { 
         // If refresh request succeeds, makeRequest is called recursively and the else condition runs 
         process(response.data, true); 
         return makeRequest(scope, address, request, basic, form); 
        }); 

UPDATE：因爲.success/.error功能沒有可鏈接（並已被標記deprecated），你應該使用.then和.catch代替。

$http.post(/*...*/) 
    .success(function(data) { 
     /* do something with data */ 
    }) 
    .error(function(err) { 
     /*...*/ 
    }); 

成爲

$http.post(/*...*/) 
    .then(function(response) { 
     /*do something with response.data */ 
    }) 
    .catch(function(response) { 
     /*...*/ 
    });