"将平面对象数组转换为嵌套对象"

Question

I have the following array, which is flattened, so I want to convert it to the nested array.

const data = [{
    "countryId": 9,
    "countryName": "Angola",
    "customerId": 516,
    "customerName": "CHEVRON (SASBU) - ANGOLA",
    "fieldId": 2000006854,
    "fieldName": "A12"
},
{
    "countryId": 9,
    "countryName": "Angola",
    "customerId": 516,
    "customerName": "CHEVRON (SASBU) - ANGOLA",
    "fieldId": 5037,
    "fieldName": "BANZALA"
}
]

I would like to have the following interface

interface Option {
    value: number,
    viewText: string,
    ids?: Set<number>,
    children?: Option[]
}

So the output should look like this

const output = [{
    "value": 9,
    "viewText": "Angola",
    "ids": [516],
    "children": [{
        "value": 516,
        "viewText": "CHEVRON (SASBU) - ANGOLA",
        "ids": [2000006854],
        "children": [{
            "viewText": "A12",
            "value": 2000006854
        }]
    }]
}]

I have been struggling with the solution, I don't know how to approach this, do I need to use a recursive function or something else, any ideas?

Update:

Here is my naive solution. The problem with this approach is that I'm manually handling nested structures.

function mapFlatToNested(data: typeof dataset) {
    const map = new Map<number, Option>()

    for (const item of data) {
        const itemFromMap = map.get(item.countryId);

        if (!itemFromMap) {
            map.set(item.countryId, {
                viewText: item.countryName,
                value: item.countryId,
                ids: new Set([item.customerId]),
                childrens: [{
                    viewText: item.customerName,
                    value: item.customerId,
                    ids: new Set([item.fieldId]),
                    childrens: [{
                        value: item.fieldId,
                        viewText: item.fieldName
                    }]
                }]
            })
        } else {
            if (!itemFromMap?.ids?.has(item.customerId)) {

                itemFromMap?.ids?.add(item.customerId);
                itemFromMap?.childrens?.push({
                    value: item.customerId,
                    viewText: item.customerName,
                    ids: new Set([item.fieldId]),
                    childrens: [{
                        value: item.fieldId,
                        viewText: item.fieldName
                    }]
                })

            } else {
                const customer = itemFromMap?.childrens?.find((customer) => customer.value === item.customerId);

                if (customer) {
                    if (!customer.ids?.has(item.fieldId)) {
                        customer.ids?.add(item.fieldId)
                        customer.childrens?.push({
                            value: item.fieldId,
                            viewText: item.fieldName,
                            ids: new Set([customer.value])
                        })
                    }
                }
            }

        }
    }
    return map
}

console.log(mapFlatToNested(dataset));

Here is the typescript playground

Answer 1

You need to map your array:

data.map(cur=>({
  value:cur.countryId,
    viewText:cur.countryName,
    ids:[cur.customerId],
    children:[{
        value:cur.customerId,
        viewText:cur.customerName,
        ids:[cur.fieldId],
        children:[{
            viewText:cur.fieldName,
            value:cur.fieldId
        }]
    }]
}))

Answer 2

Update<\/strong> : Added the generic version. It seems nicer overall, although not as targeted to the original problem. The original answer is below.