setting a call back function for observable objects

Question

I'm trying to integrate knockoutJS variables to a Jquery-UI, so to update my UI when a knockout observable changes, I need a way to call a function when observable changes. I want to set my own call back function so if my observable variable changes this call back function need to be called automatically.

Answer 1

You can call the subscribe function on a observable, giving it the callback function to be called when the observable changes.

<input data-bind="value: val"/>

var Model = function() {
  var self = this;
  this.val = ko.observable();  
  this.val.subscribe(function () {
        alert(self.val());                
  });
};
ko.applyBindings(new Model());