Primitive Map Type

[austinkelleher]

I think that having a Map primitive would be useful. Example:

const Map = require('fashion-model/Map')
const Model = require('fashion-model/Model')

const Car = Model.extend({
  properties: {
    id: String,
    name: String
  }
})

const CarMap = Map.create({
  key: String,
  value: Car,
  // Only required if the "value" is a Model and if you want to 
  // pass an array instead of an object upon "wrap"/"new"
  keyProperty: 'id',
  prototype: {
    getCarById (id) {
      return this.get(id)
    },
   deleteCarById (id) {
     return this.delete(id)
   }
  }
})

const Person = Model.extend({
  properties: {
    name: String,
    cars: CarMap
  }
})

const person = Person.wrap({
  name: 'John',
  cars: [new Car({ id: 'abc123', name: 'Tesla' })]
  // Also passing a standard key/value pair object is supported:
  //
  // cars: { 'abc123': new Car(...), ... }
})

console.log(person.getCars()) // { 'abc123': { id: 'abc123', name: 'Tesla' } }
console.log(person.getCars().getCarById('abc123')) // { id: 'abc123', name: 'Tesla' }

Thoughts @philidem?

[philidem]

I like the idea but I would rather use something like `cars: Map` and rely on the built-in implementation of `Map` ( https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map ).

…

On Mon, Jan 15, 2018 at 9:13 AM, Austin Kelleher ***@***.***> wrote: I think that having a Map primitive would be useful. Example: const Map = require('fashion-model/Map')const Model = require('fashion-model/Model') const Car = Model.extend({ properties: { id: String, name: String } }) const CarMap = Map.create({ key: String, value: Car, keyProperty: 'id', prototype: { getCarById (id) { return this.get(id) } } }) const Person = Model.extend({ properties: { name: String, cars: CarMap } }) const person = Person.wrap({ name: 'John', cars: [new Car({ id: 'abc123', name: 'Tesla' })] // Also passing a standard key/value pair object is supported: // // cars: { 'abc123': new Car(...), ... } }) console.log(person.getCars()) // { 'abc123': { id: 'abc123', name: 'Tesla' } }console.log(person.getCars().getCarById('abc123')) // { id: 'abc123', name: 'Tesla' } Thoughts @philidem <https://github.com/philidem>? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#10>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACSL_gDfj2PUdyRX-GBf1qDjD3XBH3Uiks5tK10VgaJpZM4ReeGz> .

[austinkelleher]

The whole reason for wanting this features is to be able to do runtime validation on the key/value for what is set in the Map. If we rely on the built-in implementation of Map, we will not get those guarantees. Additionally, if we clean a model that is using a standard JS Map property, the subsequent model clean implementations will not get called.

[philidem]

Oh, I read the original proposal too quickly. I do think we should try to provide a way for not having to create a Map subtype.

Maybe this instead:

const Person = Model.extend({
  properties: {
    name: String,
    cars: {type: Map, valueType: Car}
  }
})

[philidem]

If a property is a Map type then we can automatically generate set(...) method that can assist with type coercion. We would need to create a wrapper around the underlying Map object.

For example:

person.getCars().set('blah', {year: 2018, make: 'Tesla', model: 'Model 3'}) // second argument would be coerced into a car