In javascript, if we bind multiple times, only the first bind takes in the provided this value. That is because the bind function returns a new function which doesn’t have this anymore. Subsequent binds won’t have any effect on the original this.
[code] // NOT the real bind; just an example Function.prototype.bind = function(ctxt) { var fn = this; return function bound_fn() { return fn.apply(ctxt, arguments); }; } // no more ’this’ in my_bound_fn my_bound_fn = original_fn.bind(obj); [/code]
ref: https://stackoverflow.com/questions/33832384/in-javascript-the-first-bind-determines-who-this-is-binding-it-twice-or-a-s https://stackoverflow.com/questions/26545549/chaining-bind-calls-in-javascript-unexpected-result