If you are targeting browser environments, you need to use react-router-dom package, instead of react-router. They are following the same approach as React did, in order to separate the core, (react) and the platform specific code, (react-dom, react-native ) with the subtle difference that you don’t need to install two separate packages, so the environment … Read more
Here is a React Hooks specific solution for Error Warning: Can’t perform a React state update on an unmounted component. Solution You can declare let isMounted = true inside useEffect, which will be changed in the cleanup callback, as soon as the component is unmounted. Before state updates, you now check this variable conditionally: useEffect(() … Read more
The for attribute is called htmlFor for consistency with the DOM property API. If you’re using the development build of React, you should have seen a warning in your console about this.
You can post axios data by using FormData() like: var bodyFormData = new FormData(); And then add the fields to the form you want to send: bodyFormData.append(‘userName’, ‘Fred’); If you are uploading images, you may want to use .append bodyFormData.append(‘image’, imageFile); And then you can use axios post method (You can amend it accordingly) axios({ … Read more
React 16.8 +, Functional component const ScrollDemo = () => { const myRef = useRef(null) const executeScroll = () => myRef.current.scrollIntoView() // run this function from an event handler or an effect to execute scroll return ( <> <div ref={myRef}>Element to scroll to</div> <button onClick={executeScroll}> Click to scroll </button> </> ) } Click here for … Read more
I’m the primary author of a virtual-dom module, so I might be able to answer your questions. There are in fact 2 problems that need to be solved here When do I re-render? Answer: When I observe that the data is dirty. How do I re-render efficiently? Answer: Using a virtual DOM to generate a … Read more
You cannot use any of the existing lifecycle methods (componentDidMount, componentDidUpdate, componentWillUnmount etc.) in a hook. They can only be used in class components. And with Hooks you can only use in functional components. The line below comes from the React doc: If you’re familiar with React class lifecycle methods, you can think of useEffect … Read more
From React’s documentation: setState() does not immediately mutate this.state but creates a pending state transition. Accessing this.state after calling this method can potentially return the existing value. There is no guarantee of synchronous operation of calls to setState and calls may be batched for performance gains. If you want a function to be executed after … Read more
By the time script is executed, document element is not available yet, because script itself is in the head. While it’s a valid solution to keep script in head and render on DOMContentLoaded event, it’s even better to put your script at the very bottom of the body and render root component to a div … Read more
I feel like none of the answers have crystallized why mapDispatchToProps is useful. This can really only be answered in the context of the container-component pattern, which I found best understood by first reading:Container Components then Usage with React. In a nutshell, your components are supposed to be concerned only with displaying stuff. The only … Read more