Question

I wrote a class cotaining the following CoffeScript code:

class SomeClass
  # ...lots of other code...

  runner: ->
    process.nextTick =>
      if @some_condition
        @do_something_async()
      @runner()

What it is supposed to do is to wait for @some_condition to be true. This basically works, however since it really quickly loops through all of this it causes heavy resource usage. How would I do this correctly?

Answer 1

Use events to decouple conditions and code that must run when those conditions are met.

Pattern is:

1. listen for an event and set a listener that would run when the event is fired

   eventEmitter.on("myEvent", function () {
       console.log("myEvent just happened");
   });
   

2. when something in your code can make your condition become true, check for it and fire an event accordingly:

   doSomething();
   something++;
   if (something > max_something) {
       eventEmitter.emit("myEvent");
   }