Redux Essentials, Part 1: Redux Overview and Concepts
Freitag, September 20th, 2024In the end, it usually ends up as quite some more code – see kentcdodds.com/blog/how-to-use-rea… Context API is a built-in React tool that does not influence the final bundle size, and is integrated by design. Without Hooks, the Context API might not seem like much when compared to Redux. But, when combined with the useReducer Hook, we have a solution that finally solves the state management problem in React. Either way, Redux is an awesome tool, and I think you should check it out, especially if you’re working with React. Besides being used extensively by companies like Uber and Twitter, Redux has also been implemented successfully on projects such as WordPress.
Our developers broke down a few specific use cases where Context API is the better choice. That in the end leaves the configureStore call – and that are three lines. You will probably save more code by using createSlice vs manually writing a Provider. In our StateProvider, we returned our Provider component with a value prop of state and dispatch from the useReducer Hook. Now, instead of wrapping our content in a Consumer component, we can simply access our state through the value variable.
Redux Libraries and Tools
For this app, we’re going to track a single number with the current value of our counter. Because Redux is a standalone JS library with no dependencies, this example is written by only loading a single script tag for the Redux library, and uses basic JS and HTML for the UI. In practice, Redux is normally used by installing the Redux packages from NPM, and the UI is created using a library like React. The rest of the description on this page focuses solely on the Redux core library (the redux package).
Lastly, you can install the Redux DevTools that give you insights into your application’s current state to simplify debugging or testing your application. This tutorial will teach you “how Redux works”, as well as why these patterns exist. Now if the user wants to add another item to the cart, then they will have to click on the “Add to Cart” button next to the item. If we dig deeper into this statement, we see that Redux is a state management library that you can use with any JS library or framework like React, Angular, or Vue. To understand why you should use React Redux, it may help to understand what a “UI binding library” does. With Redux, you can persist some of the app’s state to localStorage and restore it after a refresh.
Redux is maintainable
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. Redux used to be my first choice for large applications but these days I much prefer to use the Context API. Still good to know Redux though just in case and many projects and companies still require you to know it. In this tutorial, we explored the differences between using Redux for state management in React apps and using the React Context API with the useContext and useReducer Hooks.
Applications that perform mainly simple actions and do not require server-side rendering probably don’t need Redux; their actions can be handled at the component level. In React (and other frameworks as well), communication between two components that don’t have a parent-child relationship is discouraged. React advises that if you must do this, you can build your global event system following Flux’s pattern — and that’s where Redux comes in.
Redux Fundamentals, Part 1: Redux Overview
And yet, far too many React developers default to Redux for state management without considering the alternatives. In this tutorial, we’ll introduce you to the React Context API for state management and explain how React Hooks and the Context API can replace Redux. It’s important to understand the kind of application you’re building, the kinds of problems that you need to solve, and what tools can best solve the problems you’re facing.
- Still good to know Redux though just in case and many projects and companies still require you to know it.
- “Actions can be recorded and replayed later, so this makes state management predictable. With the same actions in the same order, you’re going to end up in the same state.”
- The first, mapStateToProps, is a function you provide to pull data from the store when it changes, and pass those values as props to your component.
- This results in a fairly effective solution for state management in React applications.
- Each component can access the stored state without having to send down props from one component to another.
Separating out the state management into a reducer breaks up the code and makes it more readable. Same piece of application state needs to be mapped to multiple
container components. Also, you can avoid using Redux if your data comes from a single data source per view. In other words, if you don’t require data from multiple sources, there’s no need to introduce Redux.
How to use the useReducer Hook with React Context
An action object can have other fields with additional information about what happened. By convention, we put that information in a field called payload. The type field should be a string that gives this action a descriptive name, like “todos/todoAdded”.
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.
It is easy to test Redux apps because they rely on pure functions. This means tht tests can simply call a pure function with specific parameters and check if the return value matches the expected result. If the data needs to be passed from a parent to a child deep down the tree, this can still be accomplished using React utilities like Context. But when it comes what is redux to sharing the state between components on the same level, Redux is the inevitable option. In this article, we went through what is Redux and Context API and their differences. We learned, Context API is a light-weight solution which is more suited for passing data from a parent to a deeply nested child and Redux is a more robust State Management solution.
You might assume that keeping the app’s state global would result in some performance degradation. React Redux implements many performance optimizations internally so that your own connected component only re-renders when it actually needs to. There is a central store that holds the entire state of the application.
This scenario happens a lot with wrapper components that just provide layout styles, but don’t require a lot of data or configuration. It’s more practical to side-chain Redux directly into a lower-level component in this case. Imagine a pyramid structure of seven components where each component as two child components. However, situations occur where we have to share a state with a child component or a child component wants to modify the parent component’s state.
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