React Router: Navigate back to Search results - reactjs

Question

I have dynamic routes based on search results. How do I go back and see my previously rendered search results & search term in input field versus and empty Search page?
I've started looking into useHistory/useLocation hooks, but I'm lost.
1. Search page
export default function Search() {
const [searchValue, setSearchValue] = useState("");
const [isLoading, setIsLoading] = useState(false);
const [noResults, setNoResults] = useState(false);
const [data, setData] = useState([]);
const fetchData = async () => {
const res = await fetch(
`https://api.themoviedb.org/3/search/movie?api_key={API_KEY}&query=${searchValue}`
);
const data = await res.json();
const results = data.results;
if (results.length === 0) setNoResults(true);
setData(results);
setIsLoading(false);
};
function handleSubmit(e) {
e.preventDefault();
setIsLoading(true);
fetchData();
// setSearchValue("");
}
return (
<div className="wrapper">
<form className="form" onSubmit={handleSubmit}>
<input
placeholder="Search by title, character, or genre"
className="input"
value={searchValue}
onChange={(e) => {
setSearchValue(e.target.value);
}}
/>
</form>
<div className="page">
<h1 className="pageTitle">Explore</h1>
{isLoading ? (
<h1>Loading...</h1>
) : (
<div className="results">
{!noResults ? (
data.map((movie) => (
<Result
poster_path={movie.poster_path}
alt={movie.title}
key={movie.id}
id={movie.id}
title={movie.title}
overview={movie.overview}
release_date={movie.release_date}
genre_ids={movie.genre_ids}
/>
))
) : (
<div>
<h1 className="noResults">
No results found for <em>"{searchValue}"</em>
</h1>
<h1>Please try again.</h1>
</div>
)}
</div>
)}
</div>
</div>
);
}
2. Renders Result components
export default function Result(props) {
const { poster_path: poster, alt, id } = props;
return (
<div className="result">
<Link
to={{
pathname: `/results/${id}`,
state: { ...props },
}}
>
<img
src={
poster
? `https://image.tmdb.org/t/p/original/${poster}`
: "https://www.genius100visions.com/wp-content/uploads/2017/09/placeholder-vertical.jpg"
}
alt={alt}
/>
</Link>
</div>
);
}
3. Clicking a result brings you to a dynamic page for that result.
export default function ResultPage(props) {
const [genreNames, setGenreNames] = useState([]);
const {
poster_path: poster,
overview,
title,
alt,
release_date,
genre_ids: genres,
} = props.location.state;
const date = release_date.substr(0, release_date.indexOf("-"));
useEffect(() => {
const fetchGenres = async () => {
const res = await fetch(
"https://api.themoviedb.org/3/genre/movie/list?api_key={API_KEY}"
);
const data = await res.json();
const apiGenres = data.genres;
const filtered = [];
apiGenres.map((res) => {
if (genres.includes(res.id)) {
filtered.push(res.name);
}
return filtered;
});
setGenreNames(filtered);
};
fetchGenres();
}, [genres]);
return (
<div className="resultPage">
<img
className="posterBackground"
src={
poster
? `https://image.tmdb.org/t/p/original/${poster}`
: "https://www.genius100visions.com/wp-content/uploads/2017/09/placeholder-vertical.jpg"
}
alt={alt}
/>
<div className="resultBackground">
<div className="resultInfo">
<h1> {title} </h1>
</div>
</div>
</div>
);
}
4. How do I go back and see my last search results?
I'm not sure how to implement useHistory/useLocation with dynamic routes. The stuff I find online mentions building a button to click and go to last page, but I don't have a button that has to be clicked. What is someone just swipes back on their trackpad?

Answer 1

One way you could do this would be to persist the local component state to localStorage upon updates, and when the component mounts read out from localStorage to populate/repopulate state.
Use an useEffect hook to persist the data and searchValue to localStorage, when either updates.
useEffect(() => {
localStorage.setItem('searchValue', JSON.stringify(searchValue));
}, [searchValue]);
useEffect(() => {
localStorage.setItem('searchData', JSON.stringify(data));
}, [data]);
Use an initializer function to initialize state when mounting.
const initializeSearchValue = () => {
return JSON.parse(localStorage.getItem('searchValue')) ?? '';
};
const initializeSearchData = () => {
return JSON.parse(localStorage.getItem('searchData')) ?? [];
};
const [searchValue, setSearchValue] = useState(initializeSearchValue());
const [data, setData] = useState(initializeSearchData());