Then we increment the noOfItemInCart by 1, update the cart array by adding the new object passed in the action.payload shown below, and then finally return the updated object. So reducers are basically pure JS functions which take in the previous state and an action and return the newly updated state. We may very well maintain the internal state of the components inside them, but as and when an application grows bigger, it may have to share some state between components. This is not just only to show them in the view, but also to manage or update them or perform some logic based on their value.
In Array.reduce() we returned the sum of the accumulator and current value. If you take the example of our bank scenario then after withdrawal, the money in your bank vault is no longer the same. It will be updated and again, the Cashier and Vault will remain in sync with the balance left in your account. Just like the cashier the reducer always returns the new state of your application.
Application Scalability
Component takes an array of technologies and spits out buttons. If you look at the code we have written for creating actions you’ll notice that a few things are repeated in the code. For example, the same type of field is written multiple times which is not good as per the DRY principle in programming.
Red, Green, Refactor is a simple, effective strategy to help minimise state technical debt – debt cause from a lack of code hygiene. Redux as a single source of truth means that we can better maintain and improve our applications by merging state and events into a single location. This single location feeding the application is one of the key considerations developing for the architecture and scalability of an application. Whenever we call the store.dispatch function, the reducer function will be called.
Javascript
In the above code, we are trying to understand whether we are dealing with the server or client state. Notice on line 22 where we export a special wrapper function. This wrapper eliminates the need for a Provider that we would use in a normal React application. The only thing we are doing here is defining the authState what is redux for in our store and creating the action for setting the authState named setAuthState. A slice for any normal React application using Redux will be just like this. Many React developers are already familiar with Redux, and companies often want to use the same tool, if possible, across all of the projects.
- Redux is a predictable state container designed to help you write JavaScript apps that behave consistently across client, server, and native environments, and are easy to test.
- Simply said, it solves the following three major problems that developers had with Redux.
- Whenever we call the store.dispatch function, the reducer function will be called.
- We just have refactored a simple React application to use Redux.
- An e-commerce website will have several components like the cart component, user profile component, previously viewed section component, and so on.
Firstly keep aside all the extra bit stuff and let’s just go with the Redux only. Right now we will only introduce the minimum things in Redux to learn now. There is no need to go in deep initially with some concepts like React-router, Redux-form, Reselect, Ajax, Webpack, Authentication, Testing, etc. Remember that you don’t run in one day, you first need to learn to walk. Redux toolkit is beginner friendly, and you do not necessarily need previous knowledge in regular redux to start out with it. Just get to understand how state management works, and you are good to go.
While it’s mostly used as a state management tool with React, you can use it with any other JavaScript framework or library. It’s lightweight at 2KB (including dependencies), so you don’t have to worry about it making your application’s asset size bigger. One of the major reasons why Redux is so popular is its flexibility. Redux provides a wide range of features, middleware, caching, and performance. Also, Redux can separate the concerns inside your application, resulting in better code management in the future. By now you have an idea what Redux is, what state is, and how Redux is useful for managing complex state in a web application.
