Factory a mechanism to enforce encapsulation #60

OpenTechConsult · 2022-09-26T21:51:39Z

OpenTechConsult
Sep 26, 2022

Hi,

I reached chapter 7 of the book. I am on the section Factory:: A mechanism to enforce encapsulation. I can't understand how closure and scope enforce encapsulation. I can't understand the encapsulation in the given code snippet as an illustration

function createPerson (name) {
  const privateProperties = {}

  const person = {
    setName (name) {
      if (!name) {
        throw new Error('A person must have a name')
      }
      privateProperties.name = name
    },
    getName () {
      return privateProperties.name
    }
  }

  person.setName(name)
  return person
}

const person = createPerson('James Joyce')

console.log(person.getName(), person)

oscaretu · 2022-11-19T00:40:15Z

oscaretu
Nov 19, 2022

The function createPerson(name) returns an object with 2 methods: setName(name) and getName(). There isn't any other possibility of changing or accessing the value of privateProperties other that using that two methods. Those methods can access the privateProperties because a closure captures the context, and that context includes privateProperties. And the access to the value of privateProperties is encapsulated in the person object.

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Factory a mechanism to enforce encapsulation #60

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Factory a mechanism to enforce encapsulation #60

OpenTechConsult Sep 26, 2022

Replies: 1 comment

oscaretu Nov 19, 2022

OpenTechConsult
Sep 26, 2022

oscaretu
Nov 19, 2022