In redux-saga, the equivalent of the above example would be export function* loginSaga() { while(true) { const { user, pass } = yield take(LOGIN_REQUEST) try { let { data } = yield call(request.post, ‘/login’, { user, pass }); yield fork(loadUserData, data.uid); yield put({ type: LOGIN_SUCCESS, data }); } catch(error) { yield put({ type: LOGIN_ERROR, error … Read more
Redux docs recommends you to use the spread operator approach instead of the Object.assign As per the docs: An alternative approach is to use the object spread syntax proposed for the next versions of JavaScript which lets you use the spread (…) operator to copy enumerable properties from one object to another in a more … Read more
To fix this issue simply upgrade react-scripts package (check latest version with npm info react-scripts version): Replace in your package.json “react-scripts”: “^3.x.x” with “react-scripts”: “^3.4.1” (or the latest available version) (optional for some) Delete your node_modules folder Run npm install or yarn install Some people reported that this issue was caused by running npm audit … Read more
This Q&A is from 2016, and unsurprisingly I believe things have changed. The answer continues to receive upvotes, so I’m going to add in new information from other answers but leave the original answers as well. Let me know in the comments which solution works for you. Option 1. Set the default headers In the … Read more
I suspect that the problem lies in the fact that you are calling your state setter immediately inside the function component body, which forces React to re-invoke your function again, with the same props, which ends up calling the state setter again, which triggers React to call your function again…. and so on. const SingInContainer … Read more
If a parent component is updated, does React always update all the direct children within that component? No. React will only re-render a component if shouldComponentUpdate() returns true. By default, that method always returns true to avoid any subtle bugs for newcomers (and as William B pointed out, the DOM won’t actually update unless something … Read more
This warning was introduced since React V16.3.0. If you are using functional components you could wrap the setState call into useEffect. Code that does not work: const HomePage = (props) => { props.setAuthenticated(true); const handleChange = (e) => { props.setSearchTerm(e.target.value.toLowerCase()); }; return ( <div key={props.restInfo.storeId} className=”container-fluid”> <ProductList searchResults={props.searchResults} /> </div> ); }; Now you can … Read more
If you want a short snippet without any external dependencies I find this useful componentDidUpdate(prevProps, prevState) { Object.entries(this.props).forEach(([key, val]) => prevProps[key] !== val && console.log(`Prop ‘${key}’ changed`) ); if (this.state) { Object.entries(this.state).forEach(([key, val]) => prevState[key] !== val && console.log(`State ‘${key}’ changed`) ); } } Here is a small hook I use to trace updates to … Read more
connect()(AddTodo) will pass dispatch as a prop to AddTodo component, which is still useful even without state or predefined actions. Thats the reason mapDispatchToProps is not needed in your code Now in your component let AddTodo = ({ dispatch }) => { you are destructuring your props to only access dispatch. If you make use … Read more