Parse: Fulfill multiple queries in the Parse Cloud code function. The second request does not work

Question

I am trying to run multiple queries inside the Parse cloud function. The second request fails

Parse.Cloud.beforeSave ("PhoneNumbers", function (request, response) {

// Check if the same phone number for the same user exists
var PhoneNumbersObject = Parse.Object.extend('PhoneNumbers');

var duplicationQuery = new Parse.Query(PhoneNumbersObject);
duplicationQuery.equalTo('user', Parse.User.current());
duplicationQuery.equalTo('phoneNumber', request.object.get("phoneNumber"));

duplicationQuery.count({
    success: function(count) {
        if (count > 0) {
            response.error("This number is already stored");
        }
    },
    error: function(error) {
        response.error("Error " + error.code + " : " + error.message + " when storing phone number");
    }
});

var firstPhoneNumberQuery = new Parse.Query(PhoneNumbersObject);
firstPhoneNumberQuery.equalTo('user', Parse.User.current());

firstPhoneNumberQuery.find({                           //  <<<<< find doesn't work
    success: function(results) {
        if ( results.length == 0 ) {
            console.log("User first telephone number");     // <<< Never reaches here
            request.object.set("primary", true);
        } else {
            console.log("Hello");                      // <<< Never reaches here
        }
    },
    error: function(error) {
        console.log("Bye");
        response.error("Query failed. Error = " + error.message);
    }
});

response.success();

});

Answer 1

The problem is async requests. You do not wait for the request to complete before calling response.success().

Think about what you are calling in firstPhoneNumberQuery.find(), for example, putting eggs in a boil, blocks successand error- this is what you will do when it is done.

response.success() , , , , "".

promises, , response.success() success :

duplicationQuery.count({
    // ... success / error as above
}).then(function() {
    var firstPhoneNumberQuery = new Parse.Query(PhoneNumbersObject);
    firstPhoneNumberQuery.equalTo('user', Parse.User.current());
    // return the promise so we can keep chaining
    return firstPhoneNumberQuery.find();
}).then(function(results) {
    // ... success for find
    // then call success() here
    response.success();
}, function(error) {
    // ... error block for find
});

, then().

promises :

https://parse.com/docs/js_guide#promises