Issue with Object with class instances

Question

I have a holder object where I insert Class instances.

var instances = {};
$.each(response.data, function(index, value) {
    instances[value.platform.toLowerCase()] = new FetcherClass(value.platform, value.type, value.tempo, value.max);
});

value.platform is the name of the new instance.

All seems to works fine, but when I want to call a function within an instance, allways fires the function of the last instance.

For example:

instances.name1.start();

In case there are 'name1', 'name2' and 'name3' instances, the start() function fired belongs to 'name3' instance.

Here I post the output in console of Object 'instances'.

Object name1 : FetcherClass nam2 : FetcherClass name3 : FetcherClass name4 : FetcherClass name5 : FetcherClass name6 : FetcherClass name7 : FetcherClass name8 : FetcherClass name9 : FetcherClass name10 : FetcherClass proto : Object

A link to an example: JSFiddle

What's wrong?

response.data is an Array of Objects from server. FetcherClass is an Object which holds data & functions like start(). — Apalabrados
@Apalabrados You should include a minimal reproducible example — Oriol

speciesUnknown speciesUnknown · Accepted Answer · 2017-01-14T01:16:33

You have an accidental global variable in _self. The first time the constructor is called, a new global variable called _SELF was created; subsequent calls to the constructor replaced it, such that all instances of the object referred to the most recent one.

Declare a variable within the constructor for FetcherClass and use that instead.

    function FetcherClass(plataforma, type, interval, faults) {
        var SELF = this;
        SELF.PLATAFORMA = plataforma.toLowerCase();
        SELF.TYPE = type;
        SELF.INTERVAL = interval;
        SELF.MAX_INTENTOS = faults;

        SELF.start = function() {
            alert('I am '+SELF.PLATAFORMA);
        }
    }

Issue with Object with class instances

2 Answers