javascript - 如何从多个 Promise 返回 Promise

Question

我总是在控制台中看到:

1. 团队更新2
2. 添加用户到项目
3. 从项目中删除用户

但蜜蜂的顺序应该不同

var result = teamService.addOrDeleteUser(userId, newTeams, deleteTeams);
result.then(function () {
     console.log("teamsUpdated2");          
     });

具有多个 promise 的函数:

var _addOrDeleteUser = function (userId, addToProjects, removeFromProjects) {
    var deferred = $q.defer();
    var promises = [];

    promises.push(projectResource.addUserToProjects({ userId: userId }, addToProjects, function (result) {
        console.log("addUserToProjects");
        deferred.resolve();
        return result;
    }));

    promises.push(projectResource.deleteUserFromProjects({ userId: userId }, removeFromProjects, function (result) {
        console.log("deleteUserFromProjects");
        deferred.resolve();
        return result;
    }));

    return $q.all(promises);
}

Answer 1

你可以使用 promise 链 -

travelService
       .getDeparture( user )                                           // Request #1
       .then( function( departure ){
            $scope.departure = departure;                            // Response Handler #1
            return travelService.getFlight( departure.flightID );       // Request #2
        })
        .then( function( flight ){
             $scope.flight = flight;                                // Response Handler #2
             return weatherService.getForecast( $scope.departure.date ); // Request #3
        })
        .then( function( weather ){
            $scope.weather = weather;                               // Response Handler #3
        });

更多引用请参见this