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

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

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

import splitKeypath from "split-keypath";
 
function readDeepValue(input, keypath) {
  return splitKeypath(keypath).reduce((nested, key) => nested[key], input);
}
 
var input = {
  some: {
    deep: [
      {
        key: 42
      }
    ]
  }
};
 
var result = readDeepValue(input, "some.deep[0].key");
// Result is 42

License

MIT