chain-on-computed.js

var a_slice = [].slice;
Ember.ComputedProperty.prototype.chain = function(method){
  var chainedCP, dependentKey, args, func, cp = this;

  dependentKey = Ember.guidFor(cp) + '-chain';
  args = [dependentKey].concat(a_slice.call(arguments,1));

  if (typeof method === 'string') {
    method = Ember.computed[method];
  }
  chainedCP = method.apply(null,args);
  func = chainedCP.func;

  chainedCP.func = function (propertyName) {
    if (!this.__ember_meta__.cacheMeta[propertyName+'-chain']) {
      defineProperty(this, dependentKey, cp);
      this.__ember_meta__.cacheMeta[propertyName+'-chain'] = true;
    }
    return func.apply(this, arguments);
  };
  return chainedCP;
};