UNSAFE_componentWillMount() #

UNSAFE_componentWillMount() #

UNSAFE_componentWillMount()

Note

This lifecycle was previously named componentWillMount. That name will continue to work until version 17. Use the rename-unsafe-lifecycles codemod to automatically update your components.

UNSAFE_componentWillMount() is invoked just before mounting occurs. It is called before render(), therefore calling setState() synchronously in this method will not trigger an extra rendering. Generally, we recommend using the constructor() instead for initializing state.

Avoid introducing any side-effects or subscriptions in this method. For those use cases, use componentDidMount() instead.

This is the only lifecycle method called on server rendering.