parent

parent

a fundamental concept in chain-able is parent; when creating functionality, the logic separation becomes easy when the children consume and often decorate the parent.

this allows for continuous chaining through .end which returns the parent

definition

export type Class = Chain | Obj
export type ComposedClass = Chain | Chainable | Composable | Class | Fn | Obj
export type ParentType = ComposedClass

example

const {Chain, ChainedSet} = require('chain-able')

class Person extends Chain {
  constructor(parent) {
    super(parent)
    this.extend(['name', 'age', 'email'])
  }

  end() {
    this.parent.people.add(this)
    return this.parent // which is what Chainable.end does by default
  }
}

class Things extends Chain {
  constructor(parent) {
    super(parent)
    this.people = new ChainedSet(this)
  }
  person() {
    return new Person(this)
  }
}

const things = new Things()
things
  .person()
    .name('joe')
    .age(10)
    .email('@')
    .end()
  .person()
    .name('sue')
    .end()

however, `.end` can look kind of ugly, so there is an prettier way to create infinitely nestable chains, with the `FactoryChain`

const {Chain, FactoryChain, ChainedSet} = require('chain-able')

class Things extends Chain {
  constructor(parent) {
    super(parent)
    this.people = new ChainedSet(this)
  }
  person() {
    const person = new FactoryChain(this)
    person
      // .prop also accepts an optional callback as a second param,
      // for infinitely easily nestable chains
      // .props(['name', 'age', 'email']) works as well
      .prop('name')
      .prop('age')
      .prop('email')
      .chainUpDown(this.person)
      .chainUpDowns(['person'])
      .onDone(personChain => {
        this.people.add(personChain)
        return this
      })

    return person
  }
}

const things = new Things()
things
  .person()
    .name('sue')
  // here it would not .end(),
  // but we call .person, which is a .chainUpDown,
  // so it .end()s & starts another one
  .person()
    .age(100)
    .name('john')
    .email('@')
    // ^ since we called all 3 keys (age, name, email)
    // it auto .end()s

things.people.length === 3
things.people.values().pop() === {
  age: 100,
  name: 'john',
  email: '@',
}

decorateParent