JSFiddle - React, Tailwind, and code Playground

JavaScript

var o = {
    param1: 'a',
    param2: 'b',
    doAsyncStuff: function(complete, error){

        var someData = 0;        
        
        setTimeout(function(){
            someData = 1;
            complete(someData);
        }, 500);

        //or if something went wrong:
        //error(someErrorData);
    }
}

o.doAsyncStuff(function(data){
    console.log('complete', data);
}, function(data){
    console.log('error', data);
});