Meteor methods calling async server code

gistfile1.txt

Meteor methods are a means by which a client can execute synchronous code on the server as if it was local, and wait for the result before continuing.

The important word to note here is "synchronous" - meteor methods are only good "out of the box" if the server-side code it is executing is non-blocking.  So what do we do when we need to execute asynchronous code on the server?

There are 3 possible approaches:

a) Meteor.wrapAsync
b) async/await
c) fibers/future


for all 3, the client call is identical in all 3 cases:

	import { Meteor } from 'meteor/meteor';
	Meteor.call('myAsyncMethod', (err, response) => {
	  if (err) {
	    ... handle error
	    return false;
	  }
	  ... process response data
	});


a) Meteor.wrapAsync

	import { Meteor } from 'meteor/meteor';
	Meteor.methods({
	  myAsyncMethod() {
	    const asyncFunc = Meteor.wrapAsync(aCallToSomethingThatRunsAsync);
	    const something = asyncFunc();
            ... do other stuff
            return something;
	  },
	});
	

b) async/await

	import { Meteor } from 'meteor/meteor';
	Meteor.methods({
	  async myAsyncMethod() {
	    const something = await aCallToSomethingThatRunsAsync();
            ... do other stuff
            return something;
	  },
	});


c) fibers/future

	import Future from 'fibers/future';
	const future = new Future();
	aCallToSomethingThatRunsAsync((err, something) => {
          future.return(something);
	});
	return future.wait();