[wayfarer2s]

> when you actually want to know when the component was put into the DOM

You can use componentDidMount for that and its semantics are still the same.

[danabramov]

Yes, componentDidMount is the place to work with DOM. componentWillMount never worked this way—it is basically a glorified constructor from pre-ES6 era.

[madeofpalk]

Oh apologies - I really the comment as componentDidMount. My bad.