is there a way to debounce an observer

Question

I have an observer in a controller that saves the object as changes are made. The problem is it is happing too often.

changed: ( ->
  #save code goes here 
).observes("description")

I am thinking something like http://underscorejs.org/#debounce is needed?

Also It seems to save the object twice once when the attribute changes via a key input and then again when the attribute is set from the returned server value.

Any help would be great I am trying to wrap my head around ember.

Answer 1

From Ember 1.0.0, you can get a debounced observer in any View or Object by wrapping the debounce call inside another function that observes. Ember.run.debounce doesn't return a function but instead adds the function handle to a dictionary. Every subsequent time Ember.run.debounce gets called with that function handle it will check the dictionary to see the last time the function was called and debounce it as expected.

var MyView = Ember.View.extend({
    calledRarely: function() {
        console.log("This will log rarely.");
    },

    calledOften: function() {
        console.log("This will log often.");
        Ember.run.debounce(this, this.calledRarely, 1000);
    }.observes("propertyThatChangesOften")
});

Here, this.calledOften isn't debounced at all so Ember.run.debounce will actually be called as often as the property is changed. It won't call this.calledRarely until our debounce timeout has completed.