javascript parse-platform callback parse-cloud-code

Parse Query.First Success / Error Callback intermittently not called

I'm working on a Parse Cloud Code issue that has been puzzling me for a couple of days.

I have a function that will check if a user has registered for Push notifications and hasn't disabled them afterwards. It takes a response object as input, a field name to check for a PFUser pointer, and a callback.

function shouldSendPushNotification(object, field, callback){
user = object.get(field);
if(!user){
    console.log("Error: No User in object");
    return;
}
console.log('User is:');
console.log(user);

userId = user.id;
console.log('Seeking push status for user: ' +userId);
console.log(object);

userQuery = new Parse.Query(Parse.User);
userQuery.equalTo("objectId", userId);

console.log('User Query:');
console.log(userQuery);
userQuery.first
({
    success: function(userRetrieved)
    {
        console.log('Successfully found user:');
        console.log(userRetrieved);

        if(userRetrieved.get("pushEnabled") == false){
            console.log('Error: Push not enabled for user. Aborting.');
            callback(false);
            return;
        }

        console.log("Push enabled for user. Continuing.")
        callback(true);
        return;
    },
    error: function(error)
    {
        console.log('Error: Failed to find user for push check.');
        callback(false);
        return;
    }
});
}

I call this method from two locations. In a afterSave function for a "Messages" class which has a pointer reference to the PFUser (user field), and also a custom cloud function which loops through a "Reminder" Class which also has a pointer called "Owner" to PFUser.

The log output of the afterSave method is below (reverse chronological order):

I2016-04-25T08:09:07.716Z] - New object created with objectId: 3olbwjbMVW
I2016-04-25T08:09:07.679Z] - Successfully sent new message push notification to channel: user_7le4EGeKnC with message: New message recieved from Richi Rich
I2016-04-25T08:09:07.578Z] - Fetching Clinic Details for id: 7KgcJMLheu
I2016-04-25T08:09:07.577Z] - Attempting Push to channel: user_7le4EGeKnC
I2016-04-25T08:09:07.576Z] - Push enabled for user. Continuing.
I2016-04-25T08:09:07.575Z] - {"address1":"123 Sesame Street","address2":"","addressPostcode":1234,"addressState":"VIC","addressSuburb":"Port Melbourne","clinic":{"__type":"Pointer","className":"Clinic","objectId":"7KgcJMLheu"},"createdAt":"2016-03-20T09:35:52.252Z","email":"email@email.com","emailVerified":false,"firstName":"Steve","lastName":"Forbes","phone":"0400000000","pushEnabled":true,"updatedAt":"2016-04-18T00:47:54.340Z","username":"email@email.com","objectId":"7le4EGeKnC"}
I2016-04-25T08:09:07.574Z] - Successfully found user:

I2016-04-25T08:09:07.526Z] - {"where":{"objectId":"7le4EGeKnC"}}
I2016-04-25T08:09:07.525Z] - User Query:

I2016-04-25T08:09:07.524Z] - {"clinic":{"__type":"Pointer","className":"Clinic","objectId":"7KgcJMLheu"},"content":"<html><body><p style=\"font-family: serif; font-size: 26px;\">This is a test message from Parse</p></body></html>","createdAt":"2016-04-25T08:09:07.518Z","isUnread":true,"title":"Yo - Test","updatedAt":"2016-04-25T08:09:07.518Z","user":{"__type":"Pointer","className":"_User","objectId":"7le4EGeKnC"},"objectId":"3olbwjbMVW"}

I2016-04-25T08:09:07.523Z] - Seeking push status for user: 7le4EGeKnC
I2016-04-25T08:09:07.522Z] - {"objectId":"7le4EGeKnC"}
I2016-04-25T08:09:07.521Z] - User is:

For the Cloud Function:

I2016-04-25T08:09:53.838Z] - {"where":{"objectId":"7le4EGeKnC"}}
I2016-04-25T08:09:53.837Z] - User Query:

I2016-04-25T08:09:53.836Z] - {"Owner":{"__type":"Pointer","className":"_User","objectId":"7le4EGeKnC"},"createdAt":"2016-04-10T05:45:26.552Z","frequencyInterval":0,"name":"Test","nextReminderDate":{"__type":"Date","iso":"2016-04-26T06:45:00.000Z"},"pet":"Pizza","startDate":{"__type":"Date","iso":"2016-04-12T06:45:14.000Z"},"type":0,"updatedAt":"2016-04-25T07:06:46.986Z","objectId":"BGvPwnq5SB"}

I2016-04-25T08:09:53.835Z] - Seeking push status for user: 7le4EGeKnC
I2016-04-25T08:09:53.834Z] - {"objectId":"7le4EGeKnC"}
I2016-04-25T08:09:53.833Z] - User is:

As you can see the first call executes perfectly - however the second has identical input but the success/error callbacks on the userQuery.First() never get executed. I don't know why!

Solution

It would be helpful if you would include all of the functions that are referenced. As it stands, it is a bit hard to be sure of the 'big picture'.

My guess is that your cloud code function is not properly chaining promises. I would recommend adjusting your function to return a promise instead of utilizing the callback function.

What is likely happening is the the Cloud Code function is returning immediately and not waiting around for this function to complete, as it is asynchronous. Proper use of Parse.Promise will resolve this issue.