You can promisify this.setState so that you can use the React API as a promise. This is how I got it to work: class LyricsGrid extends Component { setAsyncState = (newState) => new Promise((resolve) => this.setState(newState, resolve)); Later, I call this.setAsyncState using the standard Promise API: this.setAsyncState({ lyricsCorpus, matrix, count }) .then(foo1) .then(foo2) .catch(err => … Read more
I assume the problem is caused by the response from the server arrives after the widget is disposed. Check if the widget is mounted before you call setState. This should prevent the error you are seeing: // Before calling setState check if the state is mounted. if (mounted) { setState (() => _noDataText=”No Data”); }
You can use callbacks functions to achieve this. Please refer to the below code. import ‘package:flutter/material.dart’; class RootPage extends StatefulWidget { @override _RootPageState createState() => new _RootPageState(); } class _RootPageState extends State<RootPage> { FeedPage feedPage; Widget currentPage; @override void initState() { super.initState(); feedPage = FeedPage(this.callback); currentPage = feedPage; } void callback(Widget nextPage) { setState(() { … Read more
When using state from hooks, your test must ignore implementation details like state in order to properly test it. You can still make sure the component passes the correct state into its children. You can find a great example in this blog post written by Kent C. Dodds. Here’s an excerpt from it with a … Read more
You should invoke your second function as a callback to setState, as setState happens asynchronously. Something like: this.setState({pencil:!this.state.pencil}, myFunction) However in your case since you want that function called with a parameter you’re going to have to get a bit more creative, and perhaps create your own function that calls the function in the props: … Read more
setState() is usually asynchronous, which means that at the time you console.log the state, it’s not updated yet. Try putting the log in the callback of the setState() method. It is executed after the state change is complete: this.setState({ dealersOverallTotal: total }, () => { console.log(this.state.dealersOverallTotal, ‘dealersOverallTotal1’); });
I work on React. TLDR: But can you trust React to update the state in the same order as setState is called for the same component? Yes. different components? Yes. The order of updates is always respected. Whether you see an intermediate state “between” them or not depends on whether you’re inside in a batch … Read more
In my case I was calling the setState method before the build method had completed the process of building the widgets. You can face this error if you are showing a snackBar or an alertDialog before the completion of the build method, as well as in many other cases. So, in such cases you should … Read more
Looks like you’re accidentally calling the handleButtonChange method in your render method, you probably want to do onClick={() => this.handleButtonChange(false)} instead. If you don’t want to create a lambda in the onClick handler, I think you’ll need to have two bound methods, one for each parameter. In the constructor: this.handleButtonChangeRetour = this.handleButtonChange.bind(this, true); this.handleButtonChangeSingle = … Read more
setState(updater[, callback]) is an async function: https://facebook.github.io/react/docs/react-component.html#setstate You can execute a function after setState is finishing using the second param callback like: this.setState({ someState: obj }, () => { this.afterSetStateFinished(); }); The same can be done with hooks in React functional component: https://github.com/the-road-to-learn-react/use-state-with-callback#usage Look at useStateWithCallbackLazy: import { useStateWithCallbackLazy } from ‘use-state-with-callback’; const [count, setCount] … Read more