How Redux Works Internally: An In-depth Look Into Easy State Management

This is a challenging problem in the management of state in modern web applications, especially as they grow more massive and lively. Indeed, developers using libraries like React face an enormous task in trying to track the state of components across various layers of the application. This is where Redux comes in, one of the most liked state management libraries for applications made using JavaScript. Such can make state management easy and predictable in your ReactJS based dynamic application.

Here we are going to see how Redux works, go into its very basic ideas and perhaps see how it handles data flow in your application. We will see at the end of this post what Redux does with the state and why most developers use it for building scalable applications.

It's divided into three parts: Store, Actions, Reducers. Understanding how these parts fit into the larger whole is in itself the knowledge of what Redux is.

The store forms the core part of Redux and manages all that comprises:

Holding all of your application's state, making it possible to update the state by use of dispatch(action), subscribing listeners to receive updates whenever the state changes through subscribe(listener);

To set up the store itself, we need to pass a reducer that we're going to explain next to the createStore function and return an object with a couple of methods for interacting with the store. So far, the store has an initial state but nothing's been changed by it so far.

The actions of Redux are simple JavaScript objects that can represent a change or some event to be caused in the application. Every action has one property, type, which will uniquely identify an action. Besides this property, an action may also carry another payload where information needed to change the state could be stored.

A straightforward counter-incrementing operation might look like this:

The action didn't update immediately after being dispatched - that was actually an update, sort of, to hit the Redux store every time the user interacted with the application in some way - hitting a button or filling out a form.

The reducer takes two things-an action, the state which it is currently in. A pure function. Depending on the type of the action, it sees what has happened, giving back the new state. This means the reducer does not alter the current state directly; it merely returns a new object that reflects the new state.

This is how a simple reducer that can be used to add and subtract from a counter looks:

You would find that the state is initially indifferent to the reducer, but it does return a new state every time when it cares for an action. Redux supported a very simplistic notion that changes to the state ought to be predictable and thus easier to solve.

Let us look at the main parts and understand how data moves in a Redux application. The way Redux handles data one way makes it easier to see how data moves and changes in the application. Generally, data flows in these steps:

Action creation: When an event occurs, the program creates an action. This action might be something as simple as changing a form field or incrementing a counter which then reveals what happened.

Dispatching the Action: 

For this reason, once an action is created, it sends it into the store via the dispatch() method to begin with subsequent computation.

dispatch(action) in store;

Once deployed, it may indicate that something is happening, and Redux needs to listen for an action and take the appropriate response by updating the state.

Reducer Processing:

Once an action is dispatched to the reducer, then the type of the action and the current state may be used to derive the new state.

It only creates a new state object when it has processed the action and located the correct update.

Update the Store:

Now by returning from the reducer, it means that Redux replaces the old state in the store with the new one.

Notify Subscribers: Finally, the new state is propagated to all subscribed listeners, or pieces of the store. Now they can show again or update further based on this new state. 

Frequently, you'll want to do a few different asynchronous things across a couple of applications. Perhaps logging or fetching some data from an API. Middleware is pretty useful here. Here, Redux middleware catches actions before they are passed into the reducer so you can do any sort of action without affecting your reducer logic at all-an example being the logging of actions or making requests.  

 Knowing how Redux works makes it easy to manage the state of a massive application. Redux ensures there is one prominent source of truth for stable data inflow in your application: the store; sends actions with changes that will explain those changes and changes the state with pure reducers. Middleware adds flexibility in Redux, so it can easily be handled asynchronously, but still does a great job managing a synchronous state. One-way data flow and strict rules on state management make the apps that can grow well, be well maintained, have simple debugging, and new features get added quite easily. Redux gives you a good foundation for handling how your application's state behaves, from small applications and simple counters, to big applications with lots of components and APIs.  Ready to transform your business with our technology solutions?   Contact Us today to Leverage Our ReactJS Expertise