makeStruct

MakeStruct is a lightweight fast dynamic constructor generator for JavaScript.

The aim of makeStruct is to easily generate objects with dynamic properties on the fly.

concept

A struct is used for building data structures. These structures or records are used to group related data together.

installation

To install with npm:

npm i makestruct

Reference

makeStruct( 'keys' ) : Constructor

let myModel = 'example,foo, baz, the lazy fox jumps, over the, rainbow';
const MyDynamicClass = new makeStruct(myModel);
const myDynamicObject = new MyDynamicClass();

Object.keys(myDynamicObject); // ["example","foo","baz","theLazyFoxJumps","overThe","rainbow", ... methods]

Constructor definition:

/**
 * @constructor Generates a constructor for a given data structure
 * @param {string} keys comma separated.
 * @returns {constructor} Constructor for the new struct
 */

methods

propagateArray( Array ) : void

Populates a key-value array into the Object instance properties.

const myData = [
  ['id', 1],
  ['name', 'John'],
  ['email', '[email protected]'],
];
const MyDynamicClass = new makeStruct('id, name, email');
const myDynamicObject = new MyDynamicClass();

myDynamicObject.propagateArray(myData);
// myDynamicObject { id: 1, name: 'John', email: '[email protected]' }

propagateObject( Object ) : void

Populates an Object into the Object instance properties.

const myData = {
  id: 1,
  name: 'John',
  email: '[email protected]',
};
const MyDynamicClass = new makeStruct('id, name, email');
const myDynamicObject = new MyDynamicClass();

myDynamicObject.propagateObject(myData);
// myDynamicObject { id: 1, name: 'John', email: '[email protected]' }

hasKey( 'key' ) : boolean

myDynamicObject.hasKey('name'); // true
myDynamicObject.hasKey('nome'); // false

hasValue( 'value' ) : boolean

myDynamicObject.hasValue('John'); // true
myDynamicObject.hasValue('Johnny'); // false

toArray() : Array

myDynamicObject.toArray(); // [['id', 1], ['name', 'John'], ['email', '[email protected]']]

Overview:

const Dog = new makeStruct('id, name, breed');
// Dog -> Function, constructor()
const myDog = new Dog(1, 'baxter', 'New Scotland Retriever');
myDog; // { id: 1, name: 'baxter', breed: 'New Scotland Retriever' }

myDog.id; // returns 1
myDog.name; // returns 'baxter'
myDog.breed; // returns 'New Scotland Retriever'

Type information about the example above

typeof myDog.id; // 'number'
typeof myDog.breed; // 'string'
typeof myDog; // 'object'
myDog instanceof Dog; // true
Dog.prototype.isPrototypeOf(myDog); // true

importing

// in a module (like in a React component)
import makeStruct from 'makestruct';
// outside module (like in Node JS)
const makestruct = require('makestruct');

Define some structure:

const User = new makeStruct('id, name, country');

Instantiate your new structure

const foo = new User(1, 'John', 'UK');

Access the struct properties

foo.id; // 1
foo.name; // 'john'
foo.country; // 'UK'

Struct inside a struct

// Define a structure
const User = new makeStruct('id, name, country');
// Define another structure
const UserDetails = new makeStruct('phone, age, hairColor');
// Instantiate the inner struct first
const johnInfo = new UserDetails('555-777-888', 31, 'blonde');
// instantiate the parent struct passing the child struct as param
const john = new User(1, 'John', 'US', johnInfo);

// Accessing parent struct properties
john.id; // 1
john.name; // John
john.country; // 'US'

// Accessing child struct properties
john.info.phone; // '555-777-888'
john.info.age; // 31
john.info.hairColor; // 'blonde'

You can add structs into structs into other structs... just like a matroska.

The latest information I've relative to the maximum amount of keys in a JavaScript Object is around 8.3 million in V8 so that would be the limit approximately.

TypeDefs

You can define your data structures in JavaScript with TS pragma and JSDoc like that:

// @ts-check

/**
 * @typedef UserInfo
 * @property {string} phone
 * @property {number} age
 * @property {string} hairColor
 */

/** @type {ObjectConstructor|any} */
const UserInfo = new makeStruct('phone, age, hairColor');

/** @type {UserInfo} */
const extraInfo = new UserInfo('555-777-888', 31, 'blonde');

TypeScript example:

type Dog = {
  id: number;
  name: string;
  breed: string;
};

const LeDog = new makeStruct('id, name, breed');
const myDog: Dog = new LeDog(1, 'baxter', 'Retriever');

myDog.id.includes(); // Property 'includes' does not exist on type 'number'.ts(2339)

Dynamically creating structures from a third party Object

const myAPIResponse = {
  id: 1,
  name: 'John',
  userInfo: {
    city: 'NY',
    phone: '555-666-777',
  },
  pets: ['Baxter', 'Flurfils'],
};

const MyDynamicClass = new makeStruct(Object.keys(myAPIResponse).toString());
const myDynamicObject = new MyDynamicClass();

myDynamicObject.propagate(myAPIResponse);

myDynamicObject.name; // 'John'
myDynamicObject.pets; // ['Baxter', 'Flurfils']
myDynamicObject.userInfo; // { city: 'NY', phone: '555-666-777'}

Changelog

• Added support for dynamically create structures from a third party Object

Project Status

• The project is provided as is without warranties of any kind.
• I may add d.ts in future updates but ts-pragma along with JSDoc should suffice to export types for the constructor that returns a constructor. You'll need to define your own types for the objects you create with makeStruct either way.
• If you face any problem feel free to open a new issue and I'll try to look at it asap.
• Same applies for any pull request. The project is open source and It's maintained through collaborators or by my own.