Stop event propagation applying on same event object in backbone

Question

I have applied same custom event to the event object in the backbone with 2 different callbacks.

var ourObject = {};

_.extend(ourObject, Backbone.Events);
function dancing (msg) { console.log("We are dancing. " + msg); }
function jumping (msg) { console.log("We are jumping. " + msg); }
ourObject.on("move", dancing);
ourObject.on("move", jumping);

When I trigger move event using ourObject.trigger("move", "Yeah!");,it will trigger both the callbacks.

How should I prevent triggering second callback from first callback?

Answer 1

You can pass an object containing a flag which acts as an event object as second argument:

function dancing(msg, event) {
  console.log(event); // flag: false
  event.flag = true;
  console.log("We are dancing. " + msg);
}

function jumping(msg, event) {
  console.log(event); // flag: true
  if(!event.flag) return;
  console.log("We are jumping. " + msg);
}

ourObject.trigger("move", 'test', {
  flag: false
});

Or you can simply do something like:

function dancing (msg) {
  this.dancingTriggered = true;
  console.log("We are dancing. " + msg); 
}
function jumping (msg) {
 if(this.dancingTriggered){
   this.dancingTriggered = false;
   return;
 }
 console.log("We are jumping. " + msg); 
}

Or just use simple variable available in the scope of these callbacks