Adding associative document _id to user.profile key in Accounts.onCreateUser() - function

Question

I am trying to insert a document id into the user.profile key when in Accounts.onCreateUser(), as to be able to associate a separate document in a different collection (holding user information) to a user when they are signed in.
//serverMain.js
Accounts.onCreateUser(function(options,user){
var userId = user._id;
user.profile = user.profile || {};
_.extend(user.profile, {profComp: false});
insertShopObject(userId);
return user;
});
The insert I am using is
insertShopObject(userId);
This inserts a new document with pre-set fields into a separate collection called ‘ShopList’, I have passed in the userId as a parameter which is added as a field into the ‘ShopList’ collection. I can see from the server console that the document _id is returned when I call insertShopObject(userId);
I somehow want to catch that id when the document is inserted and add it into the user.profile key on user creation like so
_.extend(user.profile,{shopId: <-- ?-->})
Here is the insertShopObject function, I have tried returning instead of console logging the ‘result’ into a holding variable with no luck.
//serverMain.js
insertShopObject = function(userId){
var newShop = {
//pre-set fields.....
}
ShopList.insert(newShop, function(error,result){
if(error){console.log(error);}
else {console.log(result)}
});
}

Answer 1

You need to make the insert synchronous for this to work. Omit the callback from ShopList.insert() and do:
insertShopObject = function(userId){
var newShop = {
//pre-set fields.....
}
var shopId = ShopList.insert(newShop);
return shopId;
}