how to work with callback when calling Meteor methods? - meteor

Question

I have noticed the callback functions never get executed all though the server method runs fine. Also from the Meteor documentation, i understand that when Meteor.Error is thrown it will notify the client but i don't see that working as well. Am i doing something fundamentally wrong?
Client
if (Meteor.isCordova) {
getContacts(function (contacts) {
$meteor.call('createContacts', contacts, function(err){
alert("in create contacts callback");
if(err && err.error === "not-logged-in"){
alert("error due to not-logged-in");
$ionicPopup.alert({
title: err.reason || "User not logged in",
template: 'Please try again after logged in',
okType: 'button-positive button-clear'
});
}
else if(err && err.error === "contacts-exists"){
$ionicPopup.alert({
title: err.reason || "Connections already exists",
template: 'Please try again after logged in',
okType: 'button-positive button-clear'
});
}
$meteor.call('createConnections');
});
});
}
function getContacts(success, error) {
function onSuccess(contacts) {
success && success(contacts);
};
var options = {};
options.multiple = true;
var fields = ["displayName", "name"];
navigator.contacts.find(fields, onSuccess, error, options);
}
Server
createContacts: function (contacts, callback) {
if (!this.userId) {
throw new Meteor.Error('not-logged-in',
'Must be logged in to update contacts')
}
var userId = this.userId, exist = Contacts.findOne({userId: userId});
log.debug("Is contacts for userId %s exist in database ? %s", userId, !! exist);
if (!exist) {
Contacts.insert({'userId': userId, 'contacts': contacts}, function () {
callback && callback();
});
} else {
log.debug("Contacts for user exists so throwing exception as contacts-exists");
var meteorErr = new Meteor.Error('contacts-exists', "Contacts are already exist");
callback && callback(meteorErr);
}
},

Answer 1

These callbacks are asynchronous. Your server-side method shouldn't invoke the callback function, nor even expect one as an argument.
You are right to pass the callback as the last argument to Meteor.call('createContacts'), but it is not up to the receiver of createContacts to determine when that callback should be invoked. In simple terms, from the client's point of view, the server's job is simply to return an 'OK' or an 'error' signal.
Remove any reference to the callback in the method definition (on the server), and expect the client to execute that callback when the server responds.
Try this:
Server
createContacts: function (contacts) {
if (!this.userId) {
throw new Meteor.Error('not-logged-in',
'Must be logged in to update contacts');
}
var userId = this.userId;
var exist = Contacts.findOne({userId: userId});
log.debug("Is contacts for userId %s exist in database ? %s", userId, !! exist);
if (!exist) {
Contacts.insert({'userId': userId, 'contacts': contacts});
} else {
log.debug("Contacts for user exists so throwing exception as contacts-exists");
throw new Meteor.Error('contacts-exists', "Contacts are already exist");
}
},
Client
$meteor.call('createContacts', contacts, function(err){
alert("in create contacts callback");
if(err && err.error === "not-logged-in"){
alert("error due to not-logged-in");
$ionicPopup.alert({
title: err.reason || "User not logged in",
template: 'Please try again after logged in',
okType: 'button-positive button-clear'
});
}
else if(err && err.error === "contacts-exists"){
$ionicPopup.alert({
title: err.reason || "Connections already exists",
template: 'Please try again after logged in',
okType: 'button-positive button-clear'
});
}
$meteor.call('createConnections');
});

Answer 2

Seems like i need to use .then() as documented in Angular-Meteor Document
Also changed the code as per amageddian