Meteor common logic code

help
1

thanks for Seeing and Answering this issue！（My English is poor~）

In my project，I have a puzzle：
When user register or buy somethings，we’ll send a system message；
so，methods.js：userRegister() or payOrder() need to invoke sendMessage();
but，which fit file or best practice to write sendMessage code

2

If this is on server as a method you can just use
Meteor.call('name.of.the.method', 'message');

3

Meteor.call is correct if userRegister() or payOrder() are executed only at the client side.
If they are executed only at the server side, write a normal function call to sendMessage().
If they are called on both server and client side, use Meteor.isServer and write a normal function call to sendMessage().