split-keypath

Splits strings into an array of keys used for reading nested data structures

split-keypath is a method that takes a string as an input and generates an array of keys that can be used for reading values from a deeply nested object. The algorithm supports extracting array keys, which is how you can specify arbitrary keys. Please see below for examples.

Install

$ npm install split-keypath

The npm package has a bundle for the browser

Examples

1import splitKeypath from "split-keypath";
2var result = splitKeypath("hello.world");
3// Result is ["hello", "world"]

1import splitKeypath from "split-keypath";
2var result = splitKeypath("hello[0].world[some really long string. with non ascii chars.]");
3// Result is ["hello", "0", "world", "some really long string. with non ascii chars."];

Practical use that reads a value from a somewhat deeply nested object hierarchy

1import splitKeypath from "split-keypath";
2
3function readDeepValue(input, keypath) {
4  return splitKeypath(keypath).reduce((nested, key) => nested[key], input);
5}
6
7var input = {
8  some: {
9    deep: [
10      {
11        key: 42
12      }
13    ]
14  }
15};
16
17var result = readDeepValue(input, "some.deep[0].key");
18// Result is 42

License

MIT