Settings View Source Storex

Frontend store with the state on the backend. You are able to mutate store state from the frontend and also from the backend. Whole communication going through WebSocket.

Important: Storex is under active development. Report issues and send proposals here.

Only diff of the store state is being sent on each mutation.

Basic usage

Installation

Add storex to deps in mix.exs:

defp deps do
  [{:storex, "~> 0.2.0"}]
end

Also you need to add storex to package.json dependencies:

{
  "storex": "file:../deps/storex",
}

Add storex websocket handler

You need to add handler Storex.Socket.Handler to cowboy dispatch.

Phoenix: Example based on Phoenix guides

config :exampleapp, ExampleApp.Endpoint,
  http: [
    dispatch: [
      {:_,
       [
         {"/storex", Storex.Socket.Handler, []},
         {:_, Phoenix.Endpoint.Cowboy2Handler, {ExampleApp.Endpoint, []}}
       ]}
    ]
  ]

Cowboy:

:cowboy_router.compile([
    {:_, [
      # ...
      {"/storex", Storex.Socket.Handler, []},
      # ...
    ]}
  ])

Create store

To create a store you need to create new elixir module with init/2 which is called when a page is loaded, every time websocket is connected it generates session_id and passes it as the first argument, params are from Javascript store declaration. Next, you can declare mutation/5 where the first argument is mutation name, second is data passed to mutation, next two params are same like in init/2, the last one is the current state of the store.

defmodule ExampleApp.Store.Counter do
  use Storex.Store

  def init(session_id, params) do
    0
  end

  # `increase` is mutation name, `data` is payload from front-end, `session_id` is current session id of connecton, `initial_params` with which store was initialized, `state` is store current state.
  def mutation("increase", _data, _session_id, _initial_params, state) do
    state = state + 1

    {:noreply, state}
  end

  def mutation("decrease", _data, _session_id, _initial_params, state) do
    state = state - 1

    {:reply, "message", state}
  end

  def mutation("set", [number], _session_id, _initial_params, state) do
    {:noreply, number}
  end
end

Connect to store

You have to connect the newly created store with a frontend side to be able to synchronise the state: params are passed as second argument in store init/2 and as third in mutation/5. You can subscribe to changes inside store state by passing option subscribe with function as a value.

import Storex from 'storex'

const store = new Storex({
  store: 'ExampleApp.Store.Counter',
  params: {},
  subscribe: (state) => {
    const state = state
  },
  connection: (state) => {
    console.log(state ? 'connected' : 'disconnected')
  }
})

Mutate store

You can mutate store from javascript with store instance:

store.commit("increase")
store.commit("decrease").then((response) => {
  response // Reply from elixir
})
store.commit("set", 10)

Or directly from elixir:

Storex.mutate(session_id, store, "increase")
Storex.mutate(session_id, store, "set", [10])

Subscribe to store state changes

You can subscribe to store state changes in javascript with function subscribe:

store.subscribe((state) => {
  const state = state
})

Subscribe to store connection

You can subscribe to store connection state changes in javascript with function connection:

store.connection((state) => {
  console.log(state ? 'connected' : 'disconnected')
})

Configuration

Session id generation library

You can change library which generate session id for stores. Module needs to have generate/0 method.

config :storex, :session_id_library, Ecto.UUID

Default params

You can set default params for all stores in Javascript which will be passed to store.

Storex.defaults.params = {
  jwt: 'someJWT'
}

Custom store address

Storex.defaults.address = 'localhost/stores'