RxJava for Grails Async Comet Example

ticktock.js

var waitingMsg = false;
function tickTock(){
    if(!waitingMsg){
        waitingMsg = true;
        var xhr = new XMLHttpRequest();
        xhr.previous_text = '';
        xhr.onreadystatechange = function(){
            if(xhr.readyState > 2){
                if(xhr.status == 200){
                    var new_response = xhr.responseText.substring(xhr.previous_text.length);
                    xhr.previous_text = xhr.responseText;
                    var elem = document.getElementById('message');
                    elem.innerHTML = new_response;

                }
                waitingMsg = false;
            }
        };
        xhr.open('get', '/ticktock', true);
        xhr.send();
    }
}
tickTock()

TickTockController.groovy

class TickTockController {

    def index() {
        Observable.create({ Subscriber subscriber ->
            task {
                for(i in (0..20)) {
                    if(i % 2 == 0) {
                        subscriber.onNext(
                            Rx.render("Tick")
                        )
                    }
                    else {
                        subscriber.onNext(
                            Rx.render("Tock")
                        )

                    }
                    // the sleep here is to simular a long lived request that takes time etc.
                    sleep 1000
                }
                subscriber.onCompleted()
            }
        } as Observable.OnSubscribe)

    }
}