It gives you access to the context and the context, the context API is all about managing data across components without the need to pass data around with props. We've got a pretty simple User class component that manages a bit of state and uses some context. Let’s review how to call on context within a functional component. Handling the useContext() Method. A component calling useContext will always re-render when the context value changes. If re-rendering the component is expensive, you can optimize it by using memoization. However you can only make use of useContext inside a functional component and not a class component and also after v16.8.0 or react which supports hooks. If you're authoring libraries, I highly recommend you ship a render prop, and maybe even a higher order component version of your hooks. We can use Reacts context in class components, but we can’t use the useContext hook. It would be messed up in class component due to difference between functional and class components. Tip. Let's refactor this over to a function component that uses the useContext and useState hooks. The react hook useContext is called inside of functional components and is used to gain access to a context that has been set somewhere upstream of the react component. Well, I only know what the docs say. Advitya-sharma April 15, 2021, 4:44am #3. yes I checked that but I’m not really getting how can I use it. Component {render {return (< MousePosition > {pos => (// etc.)} In our last article, we have discussed about using context in React to pass the data from Parent Component to Child Components which are placed at different Nesting Levels. I don’t think I have use Context with class components (or maybe I just don’t remember it). Let’s compare the difference between using Context inside of a Class component to using it inside of a functional component with the useContext Hook. Component function is called each time the component is rendered: const Foo = props => { const context = useContext(Context); // use context } There's no place in class component that would behave the same way except render function. )}} So don't sweat it! Now class components can use this hook as a render prop: class SoOldFrom4MonthsAgo extends React. The useContext Hook provides all the same functionality you’d expect from the Context API, just packaged up into a simple to use Hook that you can use inside functional components. P.S. lasjorg April 15, 2021, 4:56am #4. If you’re familiar with the context API before Hooks, useContext(MyContext) is equivalent to static contextType = MyContext in a class, or to . The context property can be used in other lifecycle methods to … Conclusion. The useContext() method accepts a context within a functional component, and works with a .Provider and .Consumer component in one call. Using the Consumer component is a neat way of getting access to the context in the render method, which has its type inferred correctly. So use context is to functional components what static contextType is to class-based components you could say. These methods apply only within class components. It is often necessary to update the context from a component that is nested somewhere deeply in the component tree. In the end the useContext hook is very simple. Get code examples like "react native use context in class component" instantly right from your google search results with the Grepper Chrome Extension. Yes the context value from Provider can be used by useContext too. Also, setting up a context provider for use with the useContext hook is exactly the same as you would do for a normal context consumer, so you can use all the same code for the context provider portion of the class component example at the start of the article. 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