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Redux: Retrieved Data for Items in a Collection

Here is a simplified version of my state tree:

{
    "radius": 8,
    "nodes": [
        { "id": 1, "x": 10, "y": 10 },
        { "id": 2, "x": 15, "y": 10 },
        { "id": 3, "x": 20, "y": 10 }
    ]
}

Essentially, I have a list of nodes, each of which has x and a y. I also have a radius number, which is used to calculate other nodes within a node radius, i.e. Close neighbors.

I need my condition to look like this:

{
    "radius": 8,
    "nodes": [
        { "id": 1, "x": 10, "y": 10, "neighbors": [2] },
        { "id": 2, "x": 15, "y": 10, "neighbors": [1, 3] },
        { "id": 3, "x": 20, "y": 10, "neighbors": [2] }
    ]
}

Calculation for neighbors is quite expensive, so I really want to calculate this if one of the node positions changes.

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* EDIT2 :

nodes: {
    nodesById: {
        "1": { "id": 1, "color": "blue", ... },
        "2": { "id": 2, "color": "red", ... },
        ...
    },
    positionsById: {
        "1": { "id": 1, "x": 0, "y": 10 },
        "2": { "id": 2, "x": 10, "y": 10 },
        ...
    }
}

, , :

export const getNeighborsById = createSelector(
    (positionsById, radius) => positionsById,
    (positionsById, radius) => radius,
    (positionsById, radius) => {
        // calculate neighbors
    }
);

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