How can I insert properties and functions inside a ref? Like this example: Then I want to use the propertie loading and the function onTest that way: How can I do that? Answer You cannot set ref on functional components because they don’t have an instance. You may not use the ref attribute on function components because they donâ€™t have instances. (source: https://reactjs.org/docs/refs-and-the-dom.html#accessing-refs) To make your example working you need to convert <MyComponent /> to class component.
I am getting this error – Can’t perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function. Here’s my useEffect hook, I used a ref called mounted to check if the component has unmounted or not but I am still getting the error when the component unmounts. (It takes about a minute for the error to show up). TIA Answer I usually store all my subscriptions on my component state and then call them when
I have a FAQ button that’s fixed onto the bottom right corner of the screen (it’s on every screen of the website), when clicked a modal pops out displaying frequent asked questions and their respective answers, I’d like the modal to display different content based on the url that the user is on. For example: if the user is on www.example.com/signup then the modal would render the content specific to the sign up process, and when the user is on www.example.com/shop only the faq’s related to shopping should appear. This should be taking into account the first part of the
I’ve been trying to create this search app where I can display the items in a table and delete items using react redux. However, on the initial load, the app shows a table but there is no data in the table. It’s an empty table. If i search for another movie name which have more than one movie for that search term, then 2 tables would be shown but I want to show everything on the same table itself. The delete button is not working as well. Is there something wrong with my action and reducer files? Action.js Reducer App.js
I’m trying to make a build environment to make an android app but I haven’t been able to succeed to build the project. The build log is as follows, It looks exactly same as the link below and I did the same thing but I can’t resolve the problem and the log that it makes is always the same. https://forums.expo.io/t/android-cannot-run-program-node-error-2-no-such-file-or-directory/37693 Answer reinstall node. delete node modules and clean and run the project again. I can’t comment so i answered.
I’m using multiple useEffect hooks to perform the componentDidMount and componentDidUpdate functionalities, however, looks like when component loads, all my useEffect fires initially… when my component mounts, I see all those console log there How could I only let my first useEffect fires, but the other three fires when the dependency changes only? Answer useEffect is not a direct replacement of componentDidMount and componentDidUpdate. Effect will run after each render, which is why you are seeing all those console logs. According to the React documentation, the second parameter of useEffect means you can choose to fire them (effects) only when
When you click on the button, it becomes gray and stays so unless you click somewhere else. Is it possible to make it return to the initial state(light gray) right after you clicked? Answer Any <button> (not just ones from Semantic-UI) has a number of different states it can be in. These states can be selected and styled with psuedo-classes in CSS. :hover is when you move your mouse over the button :active is when you have clicked down on the button but not yet released your click. :focus is when a user has used the tab key to focus
I’m learning basics of react and currently im exploring certain problem statements available on the internet. One such problem statement required me to create a react app for a text slide creator with previous , next and reset buttons. I was able to create till here – My app.js file looks something like this- and my SlideComponent.js looks something like – and my ‘MyComponent.js’ looks something like this – and the JSON file in which i wish to render the text slides from looks something like – I have basic knowledge about states and props and useEffect() components and also
i am building a project, in which when user click the buyNow button in Basket (child 2) it will pass the props back to parent where it further pass it to another child in Signin(child 3) where we call an API call(inside useEffect) to update the mysql database but it seems that the API call is called twice as in database two records are being created and in front end i got two identical invoices record but different file names. Any suggestion guys why i am facing this, please note if i remove the useEffect statement from the Signin it
For some reason I do not see webpack being kicked off. My script stops right after yarn start and never runs webpack-dev-server –watch –env=dev –open part of it in my dev script. I suppose that’s because the node service doesn’t exit and continues to run so I never get a completion hence the && webpack-dev-server –watch –env=dev –open never runs? Answer NodeJS is single threaded. It never left nodemon.