How to update nested state properties in React

Question

I\'m trying to organize my state by using nested property like this:

this.state = {
   someProperty: {
      flag:true
   }
}

But updating

Answer 1

I take very seriously the concerns already voiced around creating a complete copy of your component state. With that said, I would strongly suggest Immer.

import produce from 'immer';

 produce(this.state, s => { s.form.username = e.target.value }) } />

This should work for React.PureComponent (i.e. shallow state comparisons by React) as Immer cleverly uses a proxy object to efficiently copy an arbitrarily deep state tree. Immer is also more typesafe compared to libraries like Immutability Helper, and is ideal for Javascript and Typescript users alike.

---

Typescript utility function

function setStateDeep(comp: React.Component, fn: (s: 
Draft>) => any) {
  comp.setState(produce(comp.state, s => { fn(s); }))
}

onChange={e => setStateDeep(this, s => s.form.username = e.target.value)}