Javascript/Parse.com - 承诺，调用response.success（）承诺

Question

我有一个承诺链执行查询，检查结果，如果我找到我需要它调用response.success（），如果不，它移动到下一个查询...由于某种原因，但是当我调用response.success（）时，下一个promise会被执行。不response.success（）结束函数？

此代码实质上检查我的每个角色，以查看请求用户属于哪一个。

当我调用response.success（）时，如何停止承诺链？

Parse.Cloud.define('getUserRole', function (request, response) { 

    Parse.Cloud.useMasterKey(); 

    const NAME = "name"; 
    const USER = "user"; 
    const USERNAME = "username"; 
    const CUSTOMER_ROLE = "Customer"; 
    const BARBER_ROLE = "Barber"; 
    const ADMIN_ROLE = "Admin"; 

    var user = request[USER]; 
    if (user == null){ 
     console.log("@Null Check for user"); 
     response.success(CUSTOMER_ROLE); 
     return; 
    } else { 
     console.log("Username: " + user.get(USERNAME)); 
    } 

    //Query customers first because that is the most likely role for most cases 
    var customerRoleQuery = new Parse.Query(Parse.Role); 
    customerRoleQuery.equalTo(NAME, CUSTOMER_ROLE); 
    customerRoleQuery.first().then(function (role) { 
     console.log("@query customer Role: " + JSON.stringify(role)); 

     //Customer Role 

     var customerQuery = role.getUsers().query(); 
     customerQuery.equalTo(USERNAME, user.get(USERNAME)); 
     return customerQuery.first(); 

    }).then(function (user) { 
     console.log("@query for customer users: " + JSON.stringify(user)); 

     //Check if we found the user in the customer role 

     if (user){ 
      console.log("@ customer user"); 
      //We found the user in the customer role 
      response.success(CUSTOMER_ROLE); 
     } else { 
      console.log("@ barber role query"); 
      //We didn't find the user in the customer role, get the barber role. 
      var barberRoleQuery = new Parse.Query(Parse.Role); 
      barberRoleQuery.equalTo(NAME, BARBER_ROLE); 
      return barberRoleQuery.first(); 
     } 

    }).then(function (role) { 
     console.log("@query Barber Role: " + JSON.stringify(role)); 

     //Barber Role 

     var barberQuery = role.getUsers().query(); 
     barberQuery.equalTo(USERNAME, user.get(USERNAME)); 
     return barberQuery.first(); 

    }).then(function (user) { 
     console.log("@query for barber users: " + JSON.stringify(user)); 

     //Check if we found the user in the barber role 

     if (user){ 
      //We found the user in the barber role 
      response.success(BARBER_ROLE); 
     } else { 
      //We didn't find the user in the barber role, get the admin role 
      //This may seem unnecessary, but we can't assume if we didn't find them in the customer or barber roles they are admins. That is a security risk. 
      var adminRoleQuery = new Parse.Query(Parse.Role); 
      adminRoleQuery.equalTo(NAME, ADMIN_ROLE); 
      return adminRoleQuery.first(); 
     } 

    }).then(function (role) { 
     console.log("@query Admin Role: " + JSON.stringify(role)); 

     //Admin Role 

     var adminQuery = role.getUsers().query(); 
     adminQuery.equalTo(USERNAME, user.get(USERNAME)); 
     return adminQuery.first(); 

    }).then(function (user) { 
     console.log("@query admin users: " + JSON.stringify(user)); 

     //Check if we found the user in the admin role 
     if (user){ 
      //We found the user in the admin role 
      response.success(ADMIN_ROLE); 
     } else { 
      //Still didn't find the user in a role, just assume they are customers 
      response.success(CUSTOMER_ROLE); 
     } 

    }, function(error){ 
     console.log("@Error"); 
     response.error(error); 
    }); 

}); 

Answer 1

response.success()终止任何正在进行的非同步调用，但它本身并不终止云代码。发布的代码中发生了什么，我认为是success()被调用，然后当前许诺的then运行（这影响你的日志，但没有别的）。

我们可以做一些事情来更好地组织目前的方法下的代码，但最好还是改变方法。无需枚举代码中的角色以查看用户具有的角色。试想一下：

// return a promise that's fulfilled with any Parse.Role which has user in the 'users' relation 
function getUserRoles(user) { 
    var query = new Parse.Query(Parse.Role); 
    query.equalTo('users', user); 
    return query.find(); 
} 

包装，对于云计算的代码也很容易：

Parse.Cloud.define('getUserRole', function(request, response) { 
    getUserRoles(request.user).then(function(roles) { 
     response.success(roles); 
    }, function(error) { 
     response.error(error); 
    }); 
});