If you’re unsure about whether you need it, you probably don’t. This usually happens when your app grows to a scale where managing app state becomes a hassle and you start looking for ways to make it simplify it. So before you dive into the world of advanced state management (e.g. Redux), consider using what is redux the tools React ships with out of the box. You don’t need Redux if your application’s state is easy to manage without it. If you’re building a house, you probably don’t need a jackhammer even if you’ve learned how to use it. Consider an application with two functionalities “Users” and “Products”.
On top of that, all communication regarding reading, updating, or creating data happens via the store. Moreover, components can listen to state changes to update the UI and avoid these data inconsistency bugs. The store is a “container” (really, a JavaScript object) that holds the application state, and the only way the state can change is through actions dispatched to the store. Now imagine what happens when a state has to be shared between components that are far apart in the component tree. This makes the state difficult to maintain and less predictable.
How Redux Toolkit Is Different Than the Redux Core
Redux helps you deal with shared state management, but like any tool, it has tradeoffs. It also adds some indirection to your code, and asks you to follow certain restrictions. It’s a trade-off between short term and long term productivity. First, we define the initial state for the application by setting the count equal to zero.
Although it’s a reasonably efficient pattern that promotes pure functions, it might be an overhead for simple applications that involve only a couple of UI changes. On top of that, don’t forget that Redux is an in-memory state store. In other words, if your application crashes, you lose your entire application state. This means that you have to use a caching solution to create a backup of your application state, which again creates extra overhead. Note how in the above example, we dispatch an action on click of the button. Or rather, to be more specific, we dispatch something known as an action creator – that is, the function addItemToCart().
Redux Terms and Concepts
They are the only way you can send data from your application to your Redux store. The data can be from user interactions, API calls, or even form submissions. There is a central store that holds the entire state of the application.
State management is essentially a way to facilitate the communication and sharing of data across components. It creates a tangible data structure to represent the state of your app that you can read from and write to. That way, you can see otherwise invisible states while you’re working with them. While it’s mostly used as a state management tool with React, you can use Redux with any other JavaScript framework or library.
Why use Redux?
It’s not an easy task to manage each component’s state while sharing it with many other components. You’ll likely experience data inconsistency bugs, a fearsome nightmare for frontend developers. React is generally fast, but by default any updates to a component will cause React to re-render all of the components inside that part of the component tree. This does require work, and if the data for a given component hasn’t changed, then re-rendering is likely some wasted effort because the requested UI output would be the same. The process of subscribing to the store, checking for updated data, and triggering a re-render can be made more generic and reusable. A UI binding library like React Redux handles the store interaction logic, so you don’t have to write that code yourself.
By convention, we put that information in a field called payload. We’ll look at where and how this is important a bit later, as well as some easier ways to write immutable update logic. By defining and separating the concepts involved in state management and enforcing rules that maintain independence between views and states, we give our code more structure and maintainability. Here, we’ll dispatch the actions that will make the reducer add 1 or
subtract 1 from the current counter value. Now that we have a reducer function, we can create a store instance by
calling the Redux library createStore API.
Understanding React Redux
Rather a reducer produces a new instance of the state with all the necessary updates. We’ll talk more about actions and reducers in the following sections. Being a state management library, Redux will basically store and manage all the application’s states. While these were the patterns originally shown in the Redux docs, they unfortunately require a lot of very verbose and repetitive code. On top of that, the boilerplate-y code lead to more opportunities to make mistakes.
- Same piece of application state needs to be mapped to multiple
container components. - This makes it easier to ask for help, learn about best practices, use libraries that build on top of React Redux, and reuse your knowledge across different applications.
- This allows you to debug your applications effectively, including using powerful techniques like “time-travel debugging”.
- When a user
does something, the app will update its data and then redraw the UI with those values.
In other words, if you don’t require data from multiple sources, there’s no need to introduce Redux. You won’t run into data inconsistency problems when accessing a single data source per view. As the official binding library for React and Redux, React Redux has a large community of users. This makes it easier to ask for help, learn about best practices, use libraries that build on top of React Redux, and reuse your knowledge across different applications. If performance is a concern, the best way to improve performance is to skip unnecessary re-renders, so that components only re-render when their data has actually changed.
You can think of dispatching actions as “triggering an event” in the application. Reducers act like event listeners, and when they hear an action they are interested in, they update the state in response. We can say that Redux reducers reduce a set of actions (over time) into a single state. The difference is that with Array.reduce() it happens all at once, and with Redux, it happens over the lifetime of your running app.
This means tht tests can simply call a pure function with specific parameters and check if the return value matches the expected result. As you can see in the example above, the component does not need to provide any state or method for its children components to share data among themselves. Everything is handled by Redux, which greatly simplifies the app and makes it easier to maintain. 💡 store refers to the object that holds the application data shared between components. As the requirements for JavaScript single-page applications have
become increasingly complicated, our code must manage more state than
ever before.
This also eliminates the need to write more code, which is awesome in my opinion. When working with functional programming, it’s important to understand concepts like pure functions, anonymous functions, closures and higher order functions just to mention a few. That’s where Redux saves the day for you; it eases the complexities that spring up in such applications. If you’ve got some experience in React, you’ll know that React’s data flow is such that parent components pass down props to child components. Whenever an action is dispatched, all the reducers are activated. Each reducer filters out the action using a switch statement switching on the action type.
