Deep Flatten JavaScript Object Recursively
A solution in plain Javascript with respect to the items. It does not mutate the source array.
function flat(r, a) {
var b = {};
Object.keys(a).forEach(function (k) {
if (k !== 'items') {
b[k] = a[k];
}
});
r.push(b);
if (Array.isArray(a.items)) {
b.items = a.items.map(function (a) { return a.id; });
return a.items.reduce(flat, r);
}
return r;
}
var data = [{ "id": 1, "level": "1", "text": "Sammy", "type": "Item", "items": [{ "id": 11, "level": "2", "text": "Table", "type": "Item", "items": [{ "id": 111, "level": "3", "text": "Dog", "type": "Item", "items": null }, { "id": 112, "level": "3", "text": "Cat", "type": "Item", "items": null }] }, { "id": 12, "level": "2", "text": "Chair", "type": "Item", "items": [{ "id": 121, "level": "3", "text": "Dog", "type": "Item", "items": null }, { "id": 122, "level": "3", "text": "Cat", "type": "Item", "items": null }] }] }, { "id": 2, "level": "1", "text": "Sundy", "type": "Item", "items": [{ "id": 21, "level": "2", "text": "MTable", "type": "Item", "items": [{ "id": 211, "level": "3", "text": "MTDog", "type": "Item", "items": null }, { "id": 212, "level": "3", "text": "MTCat", "type": "Item", "items": null }] }, { "id": 22, "level": "2", "text": "MChair", "type": "Item", "items": [{ "id": 221, "level": "3", "text": "MCDog", "type": "Item", "items": null }, { "id": 222, "level": "3", "text": "MCCat", "type": "Item", "items": null }] }] }, { "id": 3, "level": "1", "text": "Bruce", "type": "Folder", "items": [{ "id": 31, "level": "2", "text": "BTable", "type": "Item", "items": [{ "id": 311, "level": "3", "text": "BTDog", "type": "Item", "items": null }, { "id": 312, "level": "3", "text": "BTCat", "type": "Item", "items": null }] }, { "id": 32, "level": "2", "text": "Chair", "type": "Item", "items": [{ "id": 321, "level": "3", "text": "BCDog", "type": "Item", "items": null }, { "id": 322, "level": "3", "text": "BCCat", "type": "Item", "items": null }] }] }];
document.write('<pre>' + JSON.stringify(data.reduce(flat, []), 0, 4) + '</pre>');With a bit of ES6 flavor
function flatten(xs) {
return xs.reduce((acc, x) => {
acc = acc.concat(x);
if (x.items) {
acc = acc.concat(flatten(x.items));
x.items = [];
}
return acc;
}, []);
}
Using _.flatMapDeep (available since Lodash 4.7):
var flatten = function(item) {
return [item, _.flatMapDeep(item.items, flatten)];
}
var result = _.flatMapDeep(data, flatten);