react-navigation: Detect when screen, tabbar is activated / appear / focus / blur

Question

Perviously when I wanted to make some actions when screen is opened I put them inside componentDidMount. For example I can fetch some data.

like this.

Answer 1

componentDidMount / componentWillUnmount does not work in all cases of navigation (like tabs).

You need to use addListener with events didFocus and didBlur to make such actions. See documentation for details