localstorm

Object/Relation Mapper for LocalStorage.

Installation

npm install localstorm

Model

Model is an ORM (Object-Relation Mapper) for localStorage, providing simple interfaces like ActiveRecord.

NOTE: Model is NOT the best efficient accessor for localStorage, BUT provides the best small and easy way to manage localStorage and automatically map the object to your Model class.

• Methods
  • new
  • save
  • find
  • update
  • delete
  • create
  • all
  • list
  • filter
• Properties
  • schema
  • nextID

How to use

class Player extends Model {}
let player = new Player({name: 'otiai10', age: 31});
player.name // 'otiai10'
player.age // 31
player._id // undefined, because not saved yet

player.save();
player._id // 1, because it's saved to localStorage

More complicated models with relations? See schema!

Methods

new

• static
• an alias for constructor

let player = Player.new({name: 'otiai20', age: 43});
player.name // 'otiai10'
player.age // 31
player._id // undefined, because not saved yet

save

let player = new Player({name: 'otiai20'});
player.save();
player._id // 2

find

• static

let player = Player.find(2);
player.name // 'otiai10'

update

player.update({name: 'otiai22'});
Player.find(player._id).name // 'otiai22'

delete

player.delete();
Player.find(player._id) // undefined

create

• static
• an alias for new and save

let player = Player.create({name: 'otiai99', age: 99});
player._id // 3

// Is equivalent to
Player.new({name: 'otiai99'}).save();

all

• static
• returns everything as a dictionary

const dict = Player.all(); // Object
dict[1].name // 'otiai10'
dict[1] instanceof Player // true

list

• static
• returns everything as an array

const players = Player.list(); // [Player]
players.length // 2

// Is equivalent to
Player.filter(() => true);

filter

• static
• returns filtered array by filterFunc

const players = Player.filter(p => p.age < 40);
players.length // 1

useStorage

• static
• replace storage with anything which satisfies Storage interface

Model.useStorage(window.sessionStorage);

// For example, you can embed any extra operation for getItem/setItem/removeItem
const storage = new MyStorageWithEffortAsyncPushing();
Model.useStorage(storage);

Properties

schema

• static
• optional, default undefined
• can define validations for each props of this model
• no validations, if schema is not set

class Player extends Model {
  static schema = {
    name: Model.Types.string.isRequired,
    age:  Model.Types.number, // optional
    location: Model.Types.shape({
      address: Model.Types.string,
      visible: Model.Types.bool.isRequired,
    }),
  }
}

with relations

class Team extends Model {
  static schema = {
    name: Model.Types.string.isRequired,
    leader: Model.Types.reference(Player),
    members: Model.Types.arrayOf(Model.Types.reference(Player)),
  }
}

nextID

• static
• optional, default timestampID
• replace it if you want to change algorythm of generating next id

Player.nextID = () => Date.now();
Player.create({name: 'otiai2017'})._id // 1488061388247
Player.create({name: 'otiai1986'})._id // 1488061388928

Types

Types API provides followings:

1. Validation data type of Model when it's saved.
2. Resolving relationship of Models.

Examples

import {Model, Types} from "localstorm";

class User extends Model {
  protected static schema = {
    name: Types.string.isRequired,
    age: Types.number,
    langs: Types.arrayOf(Types.string),
  }
}

class Team extends Model {
  protected static schema = {
    name: Types.string.isRequired,
    active: Types.bool.isRequired,
    address: Types.shape({
      country: Types.string,
      street: Types.string,
      postcode: Types.number,
    }),
    leader: Types.reference(User, {eager: true}),
    members: Types.arrayOf(Types.reference(User)),
    roles: Types.dictOf(Types.reference(User)),
  }
}