Actions

Actions have 2 purposes : update the store and propagate this change as a render event.

Overview

import { createAction } from 'dispersive';

const createBook = createAction(title => Book.objects.create({ title }), [Book]);

Basics

import { createAction } from 'dispersive';

const updateSomething = createAction(() => {

// Transaction context on Model1 and Model2

}, [Model1, Model2]);

The function createAction takes 2 arguments : a task function and a models array. Models are used to :

1. Open a transaction on each model before calling the task
2. Close the transaction on each model after calling the task
3. Propagate an event on each model (for rendering purpose)

Transaction

const startGame = createAction((game) => {
  game.players.forEach(player => {
    if (!player.ready) throw `Can't start game : ${player.name} is not ready`;

    player.position = [random(), random()];
    player.save();  
  });

  game.update({ started: true });  
}, [Game, Player]);

In the example above, if any player is not ready everything will be canceled. The transaction will be aborted. No player will have a set position and the game will not be started.

Calling actions from async functions

Most of the time, actions are called before and/or after asynchronous calls. In these cases, actions are only used by specifics async functions. It can be done with "on the fly actions".

import { runAsAction as run } from 'dispersive/action';

const fetchBookList = async () => {
  const data = await fetch('http://api...');

  return run(() => data.map(
    ({ title }) => Book.objects.create({ title })
  ), [Book]);
};