Yankee Doodle

A Lodash.pick inspired JavaScript package to pick object values from plain JavaScript objects. Other packages lacked what I needed from an object property picker so I created this. Zero dependencies and works in all major web browsers plus Node.

Getting Started

Super simple to use, although there are some limitations with what you can parse. If your objects are complicated, make them simpler! Data should be simple and easy to read.

Installing

npm i yankee-doodle

Demo

Given the the data below, you can yank values from an object using a schema or collection of schemas to build a new object with those values.

import yank from 'yankee-doodle'

const data = {
  firstName: 'John',
  lastName: 'Doe',
  dateOfBirth: '1985-01-01',
  addressDetails: {
    address1: '10 Downing Street',
    address2: null,
    address3: null,
    city: 'London',
    postcode: 'SW1A 2AB'
  },
  nested: {
    data: {
      items: {
        one: 'one',
        two: 'two',
        three: 'three'
      }
    }
  }
}

Simply spread the property names into the yank method and it will return only those values from the given object.

yank(data, 'firstName', 'lastName')
// {
//   "firstName": "John",
//   "lastName": "Doe"
// }

Have a nested object? Similar to JSON markup, use { and } to yank children properties. This can be as nested as you like.

yank(data, 'addressDetails: { address1, city }', 'firstName')
// {
//   "addressDetails": {
//     "address1": "10 Downing Street",
//     "city": "London"
//   },
//   "firstName": "John"
// }

Deeply nesting is possible like so.

yank(data, 'nested: { data: { items: { one, two } } }')
// {
//   "nested": {
//     "data": {
//       "items": {
//         "one": "one",
//         "two": "two"
//       }
//     }
//   }
// }

You can even provide your schema with whitespace if you felt so inclined to format it this way.

yank(data, `
  nested: {
    data: {
      items: {
        one,
        two
      }
    }
  }
`)
// {
//   "nested": {
//     "data": {
//       "items": {
//         "one": "one",
//         "two": "two"
//       }
//     }
//   }
// }

You can even rename properties by providing the original property name followed by -> and then the new property name you would like to change it to. This works for any given property anywhere in the schema, including nested properties.

yank(data, 'firstName->first_name', 'lastName->last_name', 'addressDetails->address_details: { city }')
// {
//   "first_name": "John",
//   "last_name": "Doe",
//   "address_details": {
//     "city": "London"
//   }
// }

Yanking properties that don't exist will result in nothing happening for that particular key. Example below demonstrates that an empty object is returned because neither of the given properties exist on the original data object.

yank(data, 'emailAddress', 'phoneNumber')
// {}

Mixing existing properties with properties that don't exist works too. The ones that don't exist simply get ignored.

yank(data, 'addressDetails: { county }', 'addressDetails: { city }', 'dateOfBirth')
// {
//   "addressDetails": {
//     "city": "London"
//   },
//   "dateOfBirth"
// }

Don't want an empty object when there are no values associated with what you're picking from? Use yank.nullify to return a null value instead.

yank.nullify(data, 'emailAddress')
// null

Todo

• Add Lodash style path keys for selecting deeply nested properties

Tests

npm run test

Authors

• Hayden Perry - Maintainer - bakewellcake

License

This project is licensed under the MIT License - see the LICENSE.md file for details.

Acknowledgments

• Heavily inspired by Lodash.pick and supick.