How to create private method/property in Ember.Object? - ember.js

Question

We can create Em.Object like this:
var foo = Em.Object.create({
somevar : '123'
});
and then use it:
foo.get('somevar');
but how to create a private property or method in Em.Object which would be accessable from the object but wouldnt be ourside?

Answer 1

There is indeed a way to have private variables in Ember objects, as follows:
MyObject = Ember.Object.extend({
init: function() {
// private variable
var a = 1;
// methods to get, set, or otherwise accesss the private variables
this.getA = function() {return a;};
this.setA = function(val) {a = val;}
// don't forget this!
this._super(...arguments);
}
});
now try
o1 = MyObject.create()
o2 = MyObject.create()
o1.setA(42);
o2.getA(); //1
In other words, you have to declare the private variables, AND any getters, setters, or other routines that want to use them, in the init hook. Of course, this means that those getters/setters will be present on each instance of the class, rather than in its prototype. That's slightly inefficient, but the same holds for any approach to private variables for classes in JavaScript.
It is conceivable that Ember could introduce a new private: {} hash on objects, but then Ember would need a lot of machinery to handle finding and controlling access to private variables across class hierarchies. It would be equivalent to redesigning or extending the language itself, which is not part of the Ember mission.
Meanwhile, the above approach works fine if the number of private instance variables is limited and the number of routines that need to access them is small. So the accepted answer that says this is impossible is, well, wrong.

Answer 2

It's not possible, since Ember.js does not provide any encapsulation mechanisms.
However, you can simply use some convention for private members. For example, prefix them with _ sign.

Answer 3

You could use a closure:
(function() {
var somePrivateProperty = 'xyz';
MyObject = Em.Object.extend({
someComputedProperty: function() {
return 'somePrivateProperty = ' + somePrivateProperty;
}).property()
})
})();

Answer 4

Is possible with a little trick:
var obj = Em.Em.Object.create(
new function(){
var privateVar = "this is private";
this.getPrivateVar = function(){
return privateVar ;
}
},
{
emberVar: "Ember var",
emberMethod : function(){
return this.getPrivateVar();
},
emberMethod1 : function(){
return privateVar ;
},
emberBinding : 'emberVar'
}
)
now if U try to get private var
obj.privateVar
> unknown
obj.getPrivateVar()
> "this is private"
obj.emberMethod()
> "this is private"
The only problem is that:
obj.emberMethod1()
> unknown