README

Simple Object Factory

Define and build/create object.

Installation

# use npm
$ npm install --save simple-object-factory
# use yarn
$ yarn add simple-object-factory

Usage

import ObjectFactory from 'simple-object-factory'
// or, you can import each function individually.
import { define, build, create } from 'simple-object-factory' 

type UserAttribute = { id: number, name: string, age: number }

class User {
  constructor(public attr: UserAttribute) {
  }
}

ObjectFactory
  .define<UserAttribute>('user', ({ id }) => ({
    id: id,
    name: `userName${id}`,
    age: 20
  }))
  .withTrait({
    underAge: () => ({
      age: 10
    }),
    senior: () => ({
      age: 60
    })
  })
  .onCreate((attr: UserAttribute) => new User(attr))


const userAttribute = build('user')
console.log(userAttribute)
// => { id: 1, name: 'userName1', age: 20 }


const user = create('user', ['underAge'])
console.log(user.attr)
// => { age: 10, id: 2, name: 'userName2' }

API

This library is broadly dividing into three functions.

define
It can define a function, receive a context, and returns an object. Following the definition, it can define the trait, resource, and function for creating an object.
build
The function is building the object with a defined function. When building, it can pass the trait and optional values.
create
The function is creating the object with a defined function. To call this function, "onCreate" or "onCreateWithClass" must be called at definition.

Function definitions

define<<T, U = Partial<T>>(key: string, func: ObjectBuilderType<T>) => DefineContext<U>)

DefineContext contains the following functions described below.

withTrait
onCreate
onCreateWithClass

The definition of Context and ObjectBuilderType is as follows.

type Context = {
  key: string
  id: number
  cycleOf: <T>(name: string) => T
}

type ObjectBuilderType<T = any> = (ctx: Context) => T

The values of Context are as follows.

key: Its value equals the key, the argument of define.
id: It increments every time "define" or "create" is called.
cycleOf: Returns the value of the array defined in "withResource".

withTrait(traits: { [key: string]: ObjectBuilderType<T> }) => DefineContext<T>

It can call after ObjectFactory.define(). The argument is the object; the key is trait name, and the value is function receive Context and returns an object.

withResource(resources: { [key: string]: any[] }) => DefineContext<T>

It can call after ObjectFactory.define(). The argument is the object; the key is resource name, and the value is array.

onCreate<U>(func: (object: T) => U) => DefineContext<T>

It can call after ObjectFactory.define(). The argument is the function, receive the value of built and returns any value.

onCreateWithClass<U extends { new(attr: T): any }>(clazz: U) => DefineContext<T>

It equals onCreaate(attr => new clazz)

build<T, U = Partial<T>>(key: string, traitNames?: string[], option?: U) => U & T

Pass the key; it returns the object defined in "define()".

create<T, U = Partial<T>, V = any>(key: string, traitNames?: string[], option?: U) => V

Pass the key; it returns the object defined in "define()" and "onCreate()".

Usage no npm install needed!