How to update single value inside specific array item in redux

Question

I have an issue where re-rendering of state causes ui issues and was suggested to only update specific value inside my reducer to reduce amount of re-rendering on a page.

Answer 1

You could use the React Immutability helpers

import update from 'react-addons-update';

// ...    

case 'SOME_ACTION':
  return update(state, { 
    contents: { 
      1: {
        text: {$set: action.payload}
      }
    }
  });

Although I would imagine you'd probably be doing something more like this?

case 'SOME_ACTION':
  return update(state, { 
    contents: { 
      [action.id]: {
        text: {$set: action.payload}
      }
    }
  });