React 18: How to manage complex nested state updates with useReducer and avoid stale closures?
I'm trying to configure I'm migrating some code and I've been struggling with this for a few days now and could really use some help. I've looked through the documentation and I'm still confused about I'm working with React 18, using `useReducer` to manage a complex nested state in my component. The state represents a tree structure where each node can have multiple children. However, I'm encountering an issue where updates to the state don't seem to reflect the latest values due to stale closures, particularly when I try to update the state based on the previous state. Here's a simplified version of what I'm working with: ```javascript const initialState = { nodes: { 1: { id: 1, children: [] }, 2: { id: 2, children: [] }, } }; function reducer(state, action) { switch (action.type) { case 'ADD_CHILD': const newNodeId = action.payload.id; const parentId = action.payload.parentId; return { ...state, nodes: { ...state.nodes, [parentId]: { ...state.nodes[parentId], children: [...state.nodes[parentId].children, newNodeId] } } }; default: return state; } } const MyComponent = () => { const [state, dispatch] = useReducer(reducer, initialState); const addChild = (parentId, newId) => { dispatch({ type: 'ADD_CHILD', payload: { parentId, id: newId } }); }; return <div>{/* Render nodes here */}</div>; }; ``` The issue arises when I try to add children based on some user interaction, and I notice that the state update doesn’t seem to take the most recent structure into account. For instance, if I add a child to node 1, then immediately try to add another child, it often fails to include the first child in its calculations. I’ve tried using functional updates with `dispatch` but am still hitting the same issue: ```javascript dispatch(prevState => ({ type: 'ADD_CHILD', payload: { parentId, id: newId }, })); ``` However, this approach doesn't seem to work since I can’t access the latest state within the dispatch call. Is there a recommended way to ensure that state updates reflect the most current version, especially when dealing with nested structures? I'm also seeing warnings about setting state inside a render method, which I suspect might be related. Any insights would be greatly appreciated! My development environment is Ubuntu 22.04. Any advice would be much appreciated. Any pointers in the right direction? Could someone point me to the right documentation? Any pointers in the right direction?