dottie

What is dottie?

The dottie npm package is a utility for safely reading and writing deep properties of objects in JavaScript. It uses dot notation strings to access deeply nested properties and provides a set of functions to manipulate these properties without worrying about whether the intermediate properties exist.

What are dottie's main functionalities?

Get

Retrieve the value of a nested property using a dot notation string.

const dottie = require('dottie');
const value = dottie.get({a: {b: {c: 'd'}}}, 'a.b.c'); // 'd'

Set

Set the value of a nested property using a dot notation string. If intermediate properties do not exist, they are created.

const dottie = require('dottie');
const obj = {};
dottie.set(obj, 'a.b.c', 'd'); // obj is now {a: {b: {c: 'd'}}}

Transform

Transform an object with dot notation string keys into a nested object structure.

const dottie = require('dottie');
const obj = { 'a.b.c': 'd' };
const transformed = dottie.transform(obj); // transformed is now {a: {b: {c: 'd'}}}

Exists

Check if a nested property exists within an object using a dot notation string.

const dottie = require('dottie');
const exists = dottie.exists({a: {b: {c: 'd'}}}, 'a.b.c'); // true

Paths

Get an array of dot notation paths for all properties in an object.

const dottie = require('dottie');
const paths = dottie.paths({a: {b: {c: 'd'}}}); // ['a.b.c']

Other packages similar to dottie

lodash.get

lodash.get is a method from the Lodash library that allows you to access deep properties of an object safely. It is similar to dottie's get function but is part of a larger utility library.

deep-get-set

deep-get-set is a small library that provides get and set functions for deep properties of an object, similar to dottie. It does not have as many features as dottie but is lightweight.

object-path

object-path is another utility that provides access to deep properties using a similar dot notation. It offers a rich set of methods like dottie and includes additional functionality such as del (delete) and has (check existence).

README

Dottie helps you easily (and without sacrificing too much performance) look up and play with nested keys in objects, without them throwing up in your face.

Install

npm install dottie

Usage

For detailed usage, check source or tests.

Get value

Gets nested value, or undefined if unreachable, or a default value if passed.

var values = {
  some: {
    nested: {
        key: 'foobar';
    }
  },
  'some.dot.included': {
    key: 'barfoo'
  }
}

dottie.get(values, 'some.nested.key'); // returns 'foobar'
dottie.get(values, 'some.undefined.key'); // returns undefined
dottie.get(values, 'some.undefined.key', 'defaultval'); // returns 'defaultval'
dottie.get(values, ['some.dot.included', 'key']); // returns 'barfoo'

Note: lodash.get() also works fine for this

Set value

Sets nested value, creates nested structure if needed

dottie.set(values, 'some.nested.value', someValue);
dottie.set(values, ['some.dot.included', 'value'], someValue);
dottie.set(values, 'some.nested.object', someValue, {
  force: true // force overwrite defined non-object keys into objects if needed
});

If you accept arbitrary/user-defined paths to set you should call Object.preventExtensions(values) first to guard against potential pollution.

Transform object

Transform object from keys with dottie notation to nested objects

var values = {
  'user.name': 'Gummy Bear',
  'user.email': '[e-mail]',
  'user.professional.title': 'King',
  'user.professional.employer': 'Candy Mountain'
};
var transformed = dottie.transform(values);

/*
{
  user: {
    name: 'Gummy Bear',
    email: '[e-mail]',
    professional: {
      title: 'King',
      employer: 'Candy Mountain'
    }
  }
}
*/

With a custom delimiter

var values = {
  'user_name': 'Mick Hansen',
  'user_email': '[e-mail]'
};
var transformed = dottie.transform(values, { delimiter: '_' });

/*
{
  user: {
    name: 'Mick Hansen',
    email: '[e-mail]'
  }
}
*/

Get paths in object

var object = {
  a: 1,
  b: {
    c: 2,
    d: { e: 3 }
  }
};

dottie.paths(object); // ["a", "b.c", "b.d.e"];

Performance

0.3.1 and up ships with dottie.memoizePath: true by default, if this causes any bugs, please try setting it to false

License

MIT