Forenote: Let’s just think this differently and disregard rules established by HTML5 and focusing only on JSX. JSX has exactly two ways of passing true, <MyComponent prop /> and <MyComponent prop={true} /> and exactly one way of passing false <MyComponent prop={false} />. I do agree this is an oddity distinguishing between HTML5 and JSX, but … Read more
If the value of props.filters did not change, then React would skip the effect. // This will only re-run if the value of `props.filters` changes useEffect(() => { fetchSomeData(props.filters); }, [props.filters]); With hooks, React does this internally unlike the implementation using componentDidUpdate where we have to compare the value of prevProps and nextProps against each … Read more
We can have a look at how div props are defined: interface IntrinsicElements { div: React.DetailedHTMLProps<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement>; } If we use React.DetailedHTMLProps<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement> as the base type we will have all properties of div. Since DetailedHTMLProps just adds ref to React.HTMLAttributes<HTMLDivElement> we can use just this as the base interface to get all div properties: … Read more
you can use the property ‘children’ to pass an element type jsx like instead of the property ‘component’, is recomended from react-native. On this way you can pass props to component example: <tab.Screen name=”home” children={()=><ComponentName propName={propValue}/>} /> is neccesary to use ‘()=>’ because the property children need a function that return a jsx element, it’s … Read more
For anyone using PropTypes >= 15.7.0 a new PropTypes.elementType was added in this pull request and was released on february 10, 2019. This prop type supports all components (native components, stateless components, stateful components, forward refs React.forwardRef, context providers/consumers). And it throws a warning when is not any of those elements, it also throws a … Read more
According to the principle of least privilege, this is a correct way: <InnerComponent name={object.name} image={object.image} /> This restricts InnerComponent from accidentally modifying original object or accessing properties that aren’t intended for it. Alternatively, properties could be picked from original object and passed as props: <InnerComponent {…pick(object, ‘name’, ‘image’)} /> If there are numerous properties that … Read more
The type that would match the function returned from invoking useState would be: setMyVar: (value: boolean | ((prevVar: boolean) => boolean)) => void; If we look at the type definition file from DefinitelyTyped [1], we can see that the second type in the return type is a dispatch: function useState<S>(initialState: S | (() => S)): … Read more
TLDR: The specific problem in your code is stated in the paragraph near the end of this answer. This is a classical problem with JavaScript’s this, I suggest you read a little bit into it if you haven’t already. To put it in short and simpler terms (not just for you, but if someone else … Read more
You can’t create a functional component with a type annotation and make it generic. So this will NOT work as T is not defined and you can’t define it on the variable level: const CollapsableDataList : React.FunctionComponent<IProps<T>> = p => { /*…*/ } You can however skip the type annotation, and make the function generic … Read more
The official docs show how to do this with ES6 component classes, but the same applies for stateless functional components. Firstly, npm install / yarn add the prop-types package if you haven’t already. Then, add your propTypes (and defaultProps too if required) after the stateless functional component has been defined, before you export it. import … Read more