collection types

Collection types

Mobile Framework provide some type definitions to help you to write your reducers. These are not classes, but just type definitions of pure JSON data structures to easily be stored in a cache.

It's up to you to use and manage these simple structures, but Typescript allows you to keep a trace of what type is your data.

Array by Id

With a regular array in JS, which has numbers as key, it's difficult to get an item by its string Id, when you want to store custom data structure like users, resource, etc...

The arrayById type is a way to store an object with id as key.

Just write

const myDummyArray: IArrayById<Dummy> = {};

Ordered array by Id

Regular ordered arrays in JS must have numbers as key, and objects, which have strings as key, are non-ordered.

The IOrderedArrayById is a combination of an IArrayById with a regular array that store the order of Ids. To get an ordered array, you just have to go this way :

const myDummyOrderedArray: IOrderedArrayById<Dummy> = {
  byId: {},
  ids: []
};

// Keep `byId` and `ids` consistent !

// Get an ordered array
myDummyOrderedArray.ids.map(id => myDummyOrderedArray.byId[id])