I found it's complex to handle this type of data in reducer.

[xywenke]

I wrote a Tree component with Redux to handle my state , the structure of the state used like this:

let cate = {
  '1': {
    expand: true,
    children: {
      '1_1': {
        expand: false,
        children: {
          '1_1_1': {
            expand: false
          },
          '1_1_2': {
            expand: false
          }
        }
      }
    }
  }
}

When I want to change cate['1']['children']['1_1']['expand'] equal true in reducer , I found it's very difficult with code like

return {
  ...state,
  //Here I don`t know how to do.
} 

I am a fresher in Redux, could you give me a solution? thank you!

[just-boris]

Try https://github.com/facebook/immutable-js. This library does all this work for you.

let cate = Immutable.fromJS({/*your tree will be here*/});
cate.setIn(["1", "children", "1_1", "expand"], true);

[simplesmiler]

Another option is https://github.com/baptistemanson/immutable-path.

[gaearon]

This is a duplicate of #994. Use reducer composition pattern. Reducers can call other reducers to handle parts of their state. Also, shopping-cart example in the repo shows how to do it.