> For the complete documentation index, see [llms.txt](https://zazapeta.gitbook.io/rx-react-store/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zazapeta.gitbook.io/rx-react-store/api/middlewares.md).

# Middleware

## Middleware <a href="#lifecycle" id="lifecycle"></a>

Middleware is a function that will be executed in a specific moment, for a specific scope, for a specific mode.

We have 2 moments of execution :

* Before (will be executed before the `dispatch`)
* After (will be executed after the `dispatch`

We have 2 scopes of execution :

* Local (will be executed only for the store that `dispatch`)
* Global (will be executed for each `dispatch` - whathever the store is dispatching)

We have 2 modes of execution :

* Parallel (will be executed in parallel mode - think `Promise.all`)
* Sequential (will be executed in first-in-first-out (FIFO) mode - think `for in`)

So we ends-up with this liste of middlewares (executed in this order) :

* BeforeGlobalParallel
* BeforeLocalParallel
* BeforeGlobalSequential
* BeforeLocalSequential

  &#x20;**DISPATCH**
* AfterGlobalParallel
* AfterLocalParallel
* AfterGlobalSequential
* AfterLocalSequential

**Middlewares list are instances of `Map`**

## Example

```javascript
import RxStore from '@zazapeta/rx-react-store';

const initialState = {
  title: 'Super App',
  version: 1,
};

const ns = 'App';

let appStore = new RxStore({ ns, initialState });
appStore.BeforeGlobalParallel.set('Perf', (state, reducer) =>
  console.time(`${reducer.name}`)
);

appStore.AfterGlobalParallel.set('Perf', (state, reducer) =>
  console.timeEnd(`${reducer.name}`)
);

appStore.AfterGlobalParallel.set('InfoLogger', (state, reducer) =>
  console.info(`[${reducer.name}] STATE:`, state),
);

export default appStore;
```