Meteor how to get the result of Collection.update on success or failure? - meteor

Question

I have a collection that is getting updated in an event handler and which is updating the collection and I would like to get the result of the update if it was a success or failure so I can do some logic based on its result. i.e. reset session values etc.
I have always been just testing the db action itself inside of an if block for inserts which worked fine however this does not seem to be working for update.
Template.customers_update.events({
'click a#cancel, click button#close' : function(event) {
event.preventDefault();
Session.set("editCustomer", false);
Session.set("customerId", null);
},
'click input[type=submit], submit form#create_customer' : function (event) {
event.preventDefault();
var customer_name = $("#customer_name").val();
var customer_address = $("#customer_address").val();
var customer_city = $("#customer_city").val();
var customer_state = $("#customer_state").val();
var customer_zip = $("#customer_zip").val();
var customer_phone = $("#customer_phone").val();
var customer_fax = $("#customer_fax").val();
var customer_eda = $("#eda_number").val();
var customer_duns = $("#duns_number").val();
if (Customers.update(Session.get("customerId"), {$set: {user_id: Meteor.user()._id, name: customer_name, address: customer_address, city: customer_city, state: customer_state, zip: customer_zip, phone: customer_phone, fax: customer_fax, eda_number: customer_eda, duns_number: customer_duns}})) {
console.log("Update Sucsess");
Session.set("editCustomer", false);
Session.set("customerId", null);
}
}
});
and in the server it is set to allow and return true
Customers.allow({
insert: function (userID, customer) {
return userID === customer.user_id;
},
update: function (userID, customer) {
return userID === customer.user_id;
},
remove: function (userID, customer) {
return userID === customer.user_id;
}
});

Answer 1

Use the third argument callback (docs)
callback Function
Optional. If present, called with an error object as its argument.

Answer 2

Your code is probably not working because the .update() only throws an exception on the server. From the docs:
On the server, if you don't provide a callback, then update blocks until the database acknowledges the write, or throws an exception if something went wrong. If you do provide a callback, update returns immediately. Once the update completes, the callback is called with a single error argument in the case of failure, or no arguments if the update was successful.
On the client, update never blocks. If you do not provide a callback and the update fails on the server, then Meteor will log a warning to the console. If you provide a callback, Meteor will call that function with an error argument if there was an error, or no arguments if the update was successful.
Change it to:
var updateQuery = {$set: {user_id: Meteor.user()._id, name: customer_name, address: customer_address, city: customer_city, state: customer_state, zip: customer_zip, phone: customer_phone, fax: customer_fax, eda_number: customer_eda, duns_number: customer_duns}}
Customers.update(Session.get("customerId"), updateQuery, function (error) {
//on error do this
});