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Matias Trujillo
Matias Trujillo

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A naturally asynchronous store

In this article you will learn about @atomico/store, a naturally asynchronous, predictable and finite state manager. but first some code .

Preview

interface State {
  api: string;
  loading: boolean;
  products: { id: number; title: string; price: number };
}

const initialState = (state: State) => ({
  api: "",
  loading: false,
  products: [],
});

async function* getProducts(state: State) {
  yield { ...state, loading: true };
  return {
    ...(yield),
    loading: false,
    products: await (await fetch(state.api)).json(),
  };
}

const store = new Store(initialState, {
  actions: { getProducts },
});
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The above code solves the following goals:

  1. Asynchrony management.
  2. Finitely predictable asynchrony.
  3. Modularity and composition.

Asynchrony management

Application events and service calls are naturally asynchronous, with @atomico/store you can use asynchronous functions or asynchronous generators to define the update cycle.

update cycle? By this I mean the states that occur sequentially when dispatching the action, example:

async function* getProducts(state: State) {
  yield { ...state, loading: true };
  return {
    ...(yield),
    loading: false,
    products: await (await fetch(state.api)).json(),
  };
}
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The previous action will generate 2 states when dispatched:

  1. state 1:{loading: true, products:[]}
  2. state 2: {loading: false, products:[...product]}

The advantage of this is that the process is clearly observable by the store and by whoever dispatches the action.

Finitely predictable asynchrony

Every action in @atomico/store is wrapped in a promise that defines when it ends its cycle, this will let you execute actions sequentially, example:

await store.actions.orderyBy();
await store.actions.insert({ id: 1000 });
await store.actions.updateAll();
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Modularity and composition

@atomico/store allows to decouple the actions and the state of the store, for a better modularization , example:

actions.js

export interface State {
  api: string;
  loading: boolean;
  products: { id: number; title: string; price: number };
}

export const initialState = (state: State) => ({
  api: "",
  loading: false,
  products: [],
});

export async function* getProducts(state: State) {
  yield { ...state, loading: true };
  return {
    ...(yield),
    loading: false,
    products: await (await fetch(state.api)).json(),
  };
}
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store.js

import * as Actions from "./actions";

export default new Store(Actions.initialStore, { actions: { Actions } });
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Example

@atomico/store is AtomicoJS project.

AtomicoJS? Open source project for the creation of interfaces based on webcomponents, @atomico/store was created with Atomico, a library of only 3kB that will allow you to create webcomponents with a functional approach, we invite you to learn more about Atomico and its tools that will improve your experience with webcomponents.

I invite you to join the Atomicojs community and learn more about our projects!

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