Develop Reference

Trigger useEffect with anotherComponents

I have 2 components, the Favorites component, makes a request to the api and maps the data to Card.
I also have a BtnFav button, which receives an individual item, and renders a full or empty heart according to a boolean.
Clicking on the BtnFav render removes a certain item from the favorites database.
What I need is that in the Favorites component, when I click on the BtnFavs component, the useEffect of Favorites is triggered again to bring the updated favorites.
How can i solve this? I have partially solved it with a global context(favoritesUser), but is there any other neater alternative?
The data flow for now would be something like this:
Favorites component fetches all the complete data and passes it to the Card component, the Card component passes individual data to the BtnFavs component.
Favorites Component:
const fetchWines = async () => {
try {
const vinos = await axios.get(`/api/favoritos/${id}`);
const arrVinos = vinos.data.map((vino) => {
return vino.product;
});
setVinosFavs(arrVinos);
} catch (err) {
console.error(err);
}
};
useEffect(() => {
fetchWines();
}, [favoritesUser]);
return (
<div>
<h1>Mis favoritos</h1>
<Card listWines={vinosFavs} />
</div>
);
BtnFavs:
const handleClickFav = (e) => {
if (!boton) {
axios.post("/api/favoritos/add", { userId, productId }).then((data) => {
setBoton(true);
return;
});
}
axios.put("/api/favoritos/delete ", { userId, productId }).then((data) => {
setBoton(false);
setFavoritesUser(data);
});
};
What I need is that in the Favorites component, when I click on the BtnFavs component, the useEffect of Favorites is triggered again to bring the updated favorites.
How can i solve this? I have partially solved it with a global context(favoritesUser), but is there any other neater alternative?

The pattern you want is called a callback function, just like the onClick of a button. You pass a function to your components that get executed given a condition. If you want fetchWines to be called again, then just pass the function in as a prop.
Favorites Component:
<Card listWines={vinosFavs} refresh={fetchWines} />
Card Component
<BtnFavs onDelete={refresh} ... />
BtnFavs Component
onDelete();
You can name it whatever you want, but generally callbacks will be named like on<condition>.
If you really wanted useEffect to be triggered then you would pass a setState function that set one of the dependencies, but I don't see a point in this case.

I will share code, because this problem its normal for me, i really want to learn and improve that.
const Favorites = () => {
const { favoritesUser } = useFavoritesContext();
const user = useSelector((state) => state.user);
const id = user.id;
const [vinosFavs, setVinosFavs] = useState([]);
const fetchWines = async () => {
try {
const vinos = await axios.get(`/api/favoritos/${id}`);
const arrVinos = vinos.data.map((vino) => {
return vino.product;
});
setVinosFavs(arrVinos);
} catch (err) {
console.error(err);
}
};
useEffect(() => {
fetchWines();
}, [favoritesUser]);
return (
<div>
<h1>My favorits</h1>
<Grid listVinos={vinosFavs} />
</div>
);
};
export default Favorites
Grid
export default function Grid({ listVinos }) {
return (
<div>
<ul className={styles.layoutDeVinos}>
{listVinos?.map((element) => {
return <WineCard key={element.id} vino={element} />;
})}
</ul>
</div>
);
}
Card
export default function WineCard({ vino }) {
return (
<>
<div>
<Link to={`/products/${vino.id}`}>
<li>
<div className={styles.card}>
<div
className={styles.img1}
style={{
backgroundImage: `url(${vino.images})`,
}}
></div>
<div className={styles.text}>{vino.descripcion}</div>
<div className={styles.catagory}>
{vino.nombre}
<i className="fas fa-film"></i>
</div>
<div className={styles.views}>
{vino.bodega}
<i className="far fa-eye"></i>{" "}
</div>
</div>
</li>
</Link>
<div className="botonesUsuario">
<BtnFavs vino={vino} />
</div>
</div>
</>
);
}
BTN FAVS
export default function BtnFavs({ vino }) {
const { setFavoritesUser } = useFavoritesContext();
const [boton, setBoton] = useState(false);
const user = useSelector((state) => state.user);
const userId = user.id;
const productId = vino.id;
useEffect(() => {
axios
.post("/api/favoritos/verify", { userId, productId })
.then((bool) => setBoton(bool.data));
}, []);
const handleClickFav = (e) => {
if (!boton) {
axios.post("/api/favoritos/add", { userId, productId }).then((data) => {
setBoton(true);
return;
});
}
axios.put("/api/favoritos/delete ", { userId, productId }).then((data) => {
setBoton(false);
setFavoritesUser(data);
});
};
return (
<>
{!user.id ? (
<div></div>
) : boton ? (
<span
class="favIcons material-symbols-rounded"
onClick={handleClickFav}
>
favorite
</span>
) : (
<span className="material-symbols-rounded" onClick={handleClickFav}>
favorite
</span>
)}
</>
);
}

Component data was gone after re rendering, even though Component was react.memo already

I have two components.
First is called: BucketTabs
Second is called:BucketForms
To have a better idea. Below pictures illustrate it.
When I switching tab, different form will be showed below.
Q: Whenever I switch from one tab to other tab, and then switch back, the content in the previous BucketForms will be gone. But, gone data are supposed to be stored into a state of that BucketForms.
In fact, I've memo the BucketForms already, so I've expected the content(data) would not be gone.
What's the problem and how could I prevent the data to be gone after switching tab.
My BucketTabs:
import { BucketForms } from '~components/BucketForms/BuckForms'
export const BucketTabs: React.FC = () => {
const items = useMemo<ContentTabsItem[]>((): ContentTabsItem[] => {
return [
{
title: '1',
renderContent: () => <BucketForms key="1" bucketCategory="1" />,
},
{
title: '2',
renderContent: () => <BucketForms key="2" bucketCategory="2" />,
},
]
}, [])
return (
<div className="row">
<div className="col">
<ContentTabs items={tabs} kind="tabs" />
</div>
</div>
)
}
BucketForms
function PropsAreEqual(prev, next) {
const result = prev.bucketCategory === next.bucketCategory;
return result;
}
interface IData {
portfolioValue?: number
}
export const BucketForms: React.FC<IProps> = React.memo(props => {
const { bucketCategory } = props
const [data, setData] = useState<IData>({
})
const view = ({
portfolioValue,
}: IData) => {
return (
<>
<div className="row portfolio">
<FormNumericInput
key="input-portfolio-value"
name="portfolioValue"
required
value={portfolioValue}
/>
</div>
</>
)
}
return (
<Form
onChange={e => {
setData({ ...data, ...e, })
}}
>
{view(data)}
</Form>
)
}, PropsAreEqual)

Callback set in the state variable of Context Provider will be undefined

I have referred other questions asked here by OPs but none seems to work for me. I have one layout and in that layout there is one toolbar which I am using to submit forms. Now to make that happen I using one FormProvider which is a Context.Provider (wraps layout component) with a state variable which stores function callback to submit a form. Now in the form component (which is loaded conditionally) I am using this setState func from context to assign form submit callback and in the toolbar using state variable from context to call that as a function. The problem I am facing is I always get state variable from context undefined. These are the snippets from my code.
FormProvider
type FormContextProps = {
setOnSubmit: (callable: Function | undefined) => void
assignOnSubmit: Dispatch<any>
setOnCancel: (callable: Function | undefined) => void
submit: (e: any) => void
cancel: () => void
}
const initAuthContextPropsState = {
setOnSubmit: () => { },
assignOnSubmit: () => { },
setOnCancel: () => { },
submit: (e: any) => { },
cancel: () => { },
}
const FormContext = createContext<FormContextProps>(initAuthContextPropsState)
const useTForm = () => {
return useContext(FormContext)
}
const FormProvider: FC = ({ children }) => {
const [onSubmit, assignOnSubmit] = useState<Function | undefined>()
const [onCancel, assignOnCancel] = useState<Function | undefined>()
const setOnSubmit = (callable: Function | undefined) => {
console.log('setOnSubmit', callable)
assignOnSubmit(callable)
console.log('setOnSubmit after', onSubmit)
}
const setOnCancel = (callable: Function | undefined) => {
assignOnCancel(callable)
}
useEffect(() => {
console.log("changed onSubmit"); // this hook is called only on first render
}, [onSubmit])
const submit = (e: any) => {
console.log('form submited', onSubmit) // this is always undefined when I click on save button on toolbar
if (onSubmit) onSubmit(e)
}
const cancel = () => {
if (onCancel) onCancel()
}
return (
<FormContext.Provider value={{ setOnSubmit, assignOnSubmit, setOnCancel, submit, cancel }}>
{children}
</FormContext.Provider>
)
}
Toolbar
const FormToolbar: FC = () => {
const {classes} = useLayout()
const {submit, cancel} = useTForm()
const submitForm = (e: any) => submit(e)
return (
<div className='toolbar' id='kt_toolbar'>
{/* begin::Container */}
<div
id='kt_toolbar_container'
className={clsx(classes.toolbarContainer.join(' '), 'd-flex flex-stack')}
>
<DefaultTitle />
{/* begin::Actions */}
<div className='py-1 d-flex align-items-center'>
{/* begin::Button */}
<button
className='btn btn-sm btn-primary me-4'
onClick={submitForm}
>
Save
</button>
<button
className='btn btn-sm btn-primary'
onClick={cancel}
>
Cancel
</button>
{/* end::Button */}
</div>
{/* end::Actions */}
</div>
{/* end::Container */}
</div>
)
}
EditForm.tsx
const EditForm: React.FC<Props> = () = {
const form = useRef() as React.MutableRefObject<HTMLFormElement>
const { setOnSubmit, assignOnSubmit } = useTForm()
useLayoutEffect(() => {
setOnSubmit(() => { form?.current.dispatchEvent(new Event('submit')) });
console.log('Form changed', form)
}, [form])
return (
<form onSubmit={formik.handleSubmit} ref={form}>
// ...
</form>
);
}
Main Component
function StaffManagement({ user, selectedLanguageId, idMenu }: Props) {
const [editing, setEditing]: [any, Function] = useState(null)
return (
<div className='row'>
<div className="col-lg-4">
<ModuleItemList
className='card-xxl-stretch mb-xl-3'
edit={setEditing}
/>
</div>
<div className="col-lg-8">
{editing && <EditForm
userId={user.id}
menuId={idMenu}
/>}
</div>
</div>
)
}

When using setState, we can do it in two ways,
setState(newState); // directly pass the new state
setState((currentState) => newState); // return the new state from a callback fn
That mean setState can accept a plain state value or a callback function which will return the new state that need to be set as the new state.
When you say,
const setOnSubmit = (callable: Function | undefined) => {
// callable => () => { form?.current.dispatchEvent(new Event('submit')) }
assignOnSubmit(callable)
}
Here React thinks you used the setState(assignOnSubmit) in the 2nd way I mentioned above, so react will call your callback and execute the form?.current.dispatchEvent(new Event('submit')). Since your callable function returns nothing, undefined will assigned to your onSubmit state.
So if you really need to store this function in a state, you have to do it as,
const setOnSubmit = (callable: Function | undefined) => {
assignOnSubmit(() => callable) // React will call the callback and return callable
}
Few Other Tips
Also do not use useLayoutEffect for this task. You can use useEffect and imrpove the performance of your application.
memoize the provider data, otherwise you will trigger unwanted re renders.
const data = useMemo(() => ({
setOnSubmit, assignOnSubmit, setOnCancel, submit, cancel
}), [submit, cancel, setOnCancel, assignOnSubmit, setOnSubmit])
return (
<FormContext.Provider value={data}>
{children}
</FormContext.Provider>
)
State updates are asynchronous. So you can't expect to console.log log the latest state
const setOnSubmit = (callable: Function | undefined) => {
console.log('setOnSubmit', callable)
assignOnSubmit(() => callable)
console.log('setOnSubmit after', onSubmit) // this won't log the latest as assignOnSubmit is async
}

you need to make <FormProvider as a parent of your Toolbar and EditForm to make your context working properly. Based on your code I don't see where you put the <FormProvider, so I'm guessing that you need to put it on your Main Component
Main Component
function StaffManagement({ user, selectedLanguageId, idMenu }: Props) {
const [editing, setEditing]: [any, Function] = useState(null)
return (
<FormProvider>
<div className='row'>
<div className="col-lg-4">
<ModuleItemList
className='card-xxl-stretch mb-xl-3'
edit={setEditing}
/>
</div>
<div className="col-lg-8">
{editing && <EditForm
userId={user.id}
menuId={idMenu}
/>}
</div>
</div>
</FormProvider>
)

How to pass callback function parameters to parent react component?

Just wondering the best way to pass the letterSelected into the useLazyQuery fetchMovies query, so that I don't have to use the static variable of "A". I was hoping there was a way to pass it directly into fetchMovies. useLazyQuery is an apollo query.
const BrowseMovies = () => {
const [fetchMovies, { data, loading}] = useLazyQuery(BROWSE_MOVIES_BY_LETTER, {
variables: {
firstLetter: "A"
}
})
return (
<div className="browserWrapper">
<h2>Browse Movies</h2>
<AlphabetSelect
pushLetterToParent={fetchMovies}
/>
{
data && !loading &&
data.browseMovies.map((movie: any) => {
return (
<div className="browseRow">
<a className="movieTitle">
{movie.name}
</a>
</div>
)
})
}
</div>
)
}
export default BrowseMovies
const AlphabetSelect = ({pushLetterToParent}: any) => {
const letters = ['A','B','C','D','E','F','G','H','I','J','K','L', 'M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','#']
const [selectedLetter, setSelectedLetter] = useState("A")
const onLetterSelect = (letter: string) => {
setSelectedLetter(letter.toUpperCase())
pushLetterToParent(letter.toUpperCase())
}
return (
<div className="alphabetSelect">
{
letters.map((letter: string) => {
return(
<div
className={selectedLetter === letter ? 'letterSelectActive' : 'letterSelect'}
onClick={() => onLetterSelect(letter)}
>
{letter}
</div>
)
})
}
</div>
)
}
export default AlphabetSelect

This appears to be a problem solved by Lifting State Up. useLazyQuery takes a gql query and options and returns a function to execute the query at a later time. Sounds like you want the child component to update the variables config parameter.
BrowseMovies
Move firstLetter state BrowseMovies component
Update query parameters/options/config from state
Add useEffect to trigger fetch when state updates
Pass firstLetter state and setFirstLetter state updater to child component
const BrowseMovies = () => {
const [firstLetter, setFirstLetter] = useState('');
const [fetchMovies, { data, loading}] = useLazyQuery(
BROWSE_MOVIES_BY_LETTER,
{ variables: { firstLetter } } // <-- pass firstLetter state
);
useEffect(() => {
if (firstLetter) {
fetchMovies(); // <-- invoke fetch on state update
}
}, [firstLetter]);
return (
<div className="browserWrapper">
<h2>Browse Movies</h2>
<AlphabetSelect
pushLetterToParent={setFirstLetter} // <-- pass state updater
selectedLetter={firstLetter} // <-- pass state
/>
{
data && !loading &&
data.browseMovies.map((movie: any, index: number) => {
return (
<div key={index} className="browseRow">
<a className="movieTitle">
{movie.name}
</a>
</div>
)
})
}
</div>
)
}
AlphabetSelect
Attach pushLetterToParent callback to div's onClick handler
const AlphabetSelect = ({ pushLetterToParent, selectedLetter }: any) => {
const letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ#';
return (
<div className="alphabetSelect">
{
letters.split('').map((letter: string) => {
return(
<div
key={letter}
className={selectedLetter === letter ? 'letterSelectActive' : 'letterSelect'}
onClick={() => pushLetterToParent(letter.toUpperCase())}
>
{letter}
</div>
)
})
}
</div>
)
}

Load more data on scroll

I have a page with a search input, once the user clicks on submit the results come up.
There can be a lot of results (usually not but there can be thousands of results) and I don't want to load them all at once, how can I get a few dozens and fetch more results from he API as the user scrolls down, what's the correct way to do that? I was thinking that Lodash throttle can fit but I couldn't find a good example for it.
This is my react component:
const getContacts = async (searchString) => {
const { data: contactsInfo} = await axios.get(`api/Contats/Search?contactNum=${searchString}`);
return contactsInfo;
};
export default class Home extends React.Component {
state = {
contactsInfo: [],
searchString: '',
};
handleSubmit = async () => {
const { searchString } = this.state;
const contactsInfo = await getContacts(searchString);
this.setState({ contactsInfo });
};
onInputChange = e => {
this.setState({
searchString: e.target.value,
});
};
onMouseMove = e => {
};
render() {
const { contactsInfo, searchString, } = this.state;
return (
<div css={bodyWrap} onMouseMove={e => this.onMouseMove(e)}>
<Header appName="VERIFY" user={user} />
{user.viewApp && (
<div css={innerWrap}>
<SearchInput
searchIcon
value={searchString || ''}
onChange={e => this.onInputChange(e)}
handleSubmit={this.handleSubmit}
/>
{contactsInfo.map(info => (
<SearchResultPanel
info={info}
isAdmin={user.isAdmin}
key={info.id}
/>
))}
</div>
)}
<Footer />
</div>
);
}
}

If the API supports pagination then you can use React-Infinite-Scroll. It looks like this
<div style="height:700px;overflow:auto;">
<InfiniteScroll
pageStart={0}
loadMore={loadFunc}
hasMore={true || false}
loader={<div className="loader">Loading ...</div>}
useWindow={false}>
{items}
</InfiniteScroll>
</div>
However if the REST API does not support it, you can still load the data and show them in chunks to the user with the same library but you would need to handle the current load state by yourself.