title: get tags: object,intermediate

Retrieve a set of properties indicated by the given selectors from an object.

Use Array.prototype.map() for each selector, String.prototype.replace() to replace square brackets with dots, String.prototype.split('.') to split each selector, Array.prototype.filter() to remove empty values and Array.prototype.reduce() to get the value indicated by it.

Get

export const get = (
  from: any,
  selector: string,
  defaultValue: any = undefined
) =>
  selector
    .replace(/\[([^\[\]]*)\]/g, ".$1.")
    .split(".")
    .filter((t) => t !== "")
    .reduce((prev, cur) => prev && prev[cur], from) || defaultValue;

GetAll

export const getAll = (from: any, ...selectors: string[]) =>
  [...selectors].map((s) => get(from, s));

const obj = {
  selector: { to: { val: "val to select" } },
  target: [1, 2, { a: "test" }],
};

get(obj, "selector.to.val"); //"val to select"
get(obj, "selector.to1.val", null); // null
get(obj, "selector.to1.val"); // undefined
getAll(obj, "selector.to.val", "target[0]", "target[2].a"); // ['val to select', 1, 'test']