What is :: before this keyword in React JS?

Question

I see some syntax like below in some react-js libraries. What is that mean and how can help me in my codes?

const inputAttributes = {
  id: 'events-playground',
  placeholder: 'Where are you now?',
  onChange: ::this.onInputChanged,
  onBlur: ::this.onInputBlurred
};

Thanks.

Answer 1

It is new ES7 syntax for .bind,

equivalent in ES5

const inputAttributes = {
  id: 'events-playground',
  placeholder: 'Where are you now?',
  onChange: this.onInputChanged.bind(this),
  onBlur: this.onInputBlurred.bind(this)
};