REACT REDUX HOOKS CODE

This parameter can either be a function, or an object. It receives the entire store state and should return an object of data this component needs. We will go through below main points in this article:īefore Hooks, we always used a connect() which is a higher-order component and wrapper to our component, connect() read values from the Redux store.Ĭonnect() takes two arguments, both optional:Ĭalled every time the store state changes. As we have seen in this article the differences are subtle.Before reading this article you should know about React & Redux, its working. If you don't make a decision upfront you might be creating more decision fatigue because it's not always clear why one method is a better approach over another. You might choose to not confine yourself to using the connect ( ) or Redux hooks. If you don't know what that is and just want to get started using React-Redux I recommend the hooks approach. Understand what you are optimizing for and choose the method that best suits that. When this article was first written there was no official recommendation. The redux style-guide now recommends using the hooks API. Let me know if you would like a video tutorial on this problem.

The docs have a lot of information on this issue but it's hard to grasp exactly how it would affect your code. The docs go into detail about a problem that can arise through Redux hook usage. But to truly get an understanding of the details of the hooks read the official documentation. This article provides a framework to compare the approaches through the theme of nudging.

Read the docs for a more in-depth understanding The trade-off is a reduction on the Separation of Concerns spectrum and the need to be aware of when to use mo to get the same performance optimizations. Using React hooks useSelector ( ) forgoes the need to use the connect function and embeds that logic within the components themselves. What approach truly give your app better performance is best left decided to actual testing. You can get around this by always returning the same object. When returning an object be aware that unless it's the same object by reference equality the component will re-render even if the properties of the object are the same.

UseSelector ( ) will cause re-renders if the value it produces has changed. Let's write some tests for this connect ( ) example:

REACT REDUX HOOKS CODE

The second is the glue code written by connect ( ), it glues redux and our inner component together through the use of a Higher Order Component. The first being what we will call the inner component, this component on its own is unaware that redux even exists. When making use of the connect ( ) our component code is separated into two parts. When 'Very Separated' we have small pieces of code and it's a nightmare to figure out how they all work together. This can seem ironic because React hooks are a tool to help with separation and code reuse, but in react-redux they do couple redux to our components more than connect ( ). Redux hooks such as useSelector ( ) reduce separation because the components include the redux glue code. When 'Not Separated' we have large files where it's hard to reuse any one piece. There's a spectrum of Separation where maintainability becomes a problem at the extreme ends. When following the Separation of concerns principle your code becomes easier to test and reuse. It becomes clear how organized your code is by its concerns when writing tests for it. Better performance optimizations by defaultĪ lens we can use to understand the differences between hooks and the connect ( ) is unit tests: How they differ for each and in-turn what direction of code style they nudge you towards.

React redux hooks