I am create custom hook that fetch requests network.I want to call custom hook when form submit button clicked but depending on hook rules i can't do that. how to can implement this scenario?
this custom hook:
const useRequest = (url, method, dependencies, data = null) => {
const [response, setResponse] = useState(null);
const [error, setError] = useState(null);
const [loading, setLoading] = useState(false);
useEffect(() => {
const fetchData = async () => {
setLoading(true);
try {
const res = await request[method](url, data);
setResponse(res);
setLoading(false);
} catch (e) {
setError(e);
setLoading(false);
}
};
fetchData();
}, dependencies);
return { response, error, loading };
};
Move fetchData function out of useEffect and export it:
const useRequest = (url, method, dependencies, data = null) => {
const [response, setResponse] = useState(null);
const [error, setError] = useState(null);
const [loading, setLoading] = useState(false);
const fetchData = async () => {
setLoading(true);
try {
const res = await request[method](url, data);
setResponse(res);
setLoading(false);
} catch (e) {
setError(e);
setLoading(false);
}
};
useEffect(() => {
fetchData();
}, dependencies);
return { response, error, loading, fetchData };
};
Than when you can call it anywhere in your code.
Related
How to clean up react request in react hooks. I read that in need to enter in my hook AbortController but I don't know how. I using next.js. What are best methods to eliminate this problem ? And I get this warning:
Warning: can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function.
This is my custom hook to fetch data:
import { useState, useEffect, useCallback } from 'react'
import { MOVIE_API_URL, MOVIE_KEY } from '../../config'
export const useMovieDetailsFetch = (movieId) => {
const [state, setState] = useState({})
const [loading, setLoading] = useState(true)
const [error, setError] = useState(false)
const fetchData = useCallback(async () => {
setError(false)
setLoading(true)
try {
const movieDetailsEndpoint = `${MOVIE_API_URL}movie/${movieId}?api_key=${MOVIE_KEY}`
const result = await (await fetch(movieDetailsEndpoint)).json()
const creditsEndpoint = `${MOVIE_API_URL}movie/${movieId}/credits?api_key=${MOVIE_KEY}`
const creditsResult = await (await fetch(creditsEndpoint)).json()
// Filtring in crew for directors only
const movieDirectors = creditsResult.crew.filter(
(member) => member.job === 'Director'
)
setState({
...result,
movieDirectors,
actors: creditsResult.cast,
})
} catch (error) {
setError(true)
}
setLoading(false)
}, [movieId])
useEffect(() => {
fetchData()
}, [fetchData])
return [state, loading, error]
}
Using an abort controller, in its rawest form:
const controller = new AbortController();
const { signal } = controller;
...
fetch(url, { signal });
...
// abort
controller.abort();
To abort an in-flight fetch in effect hook
useEffect(() => {
const controller = new AbortController();
const { signal } = controller;
fetch(url, { signal });
return () => {
controller.abort(); // abort on unmount for cleanup
};
}, []);
I found this article very informative when I needed to develop a way to cancel fetch requests.
Edit
The signal needs to be added to the fetch requests options object. You can also define the async fetchData function inside the effect (this is normal), so it's all enclosed in the effect hook's callback scope.
export const useMovieDetailsFetch = (movieId) => {
const [state, setState] = useState({})
const [loading, setLoading] = useState(true)
const [error, setError] = useState(false)
useEffect(() => {
const controller = new AbortController();
const { signal } = controller;
const fetchData = async () => {
setError(false);
setLoading(true);
try {
const movieDetailsEndpoint = `${MOVIE_API_URL}movie/${movieId}?api_key=${MOVIE_KEY}`;
const result = await (
await fetch(movieDetailsEndpoint, { signal })
).json();
const creditsEndpoint = `${MOVIE_API_URL}movie/${movieId}/credits?api_key=${MOVIE_KEY}`;
const creditsResult = await (
await fetch(creditsEndpoint, { signal })
).json();
// Filtring in crew for directors only
const movieDirectors = creditsResult.crew.filter(
(member) => member.job === 'Director'
);
setState({
...result,
movieDirectors,
actors: creditsResult.cast,
});
} catch (error) {
setError(true);
}
setLoading(false);
}
fetchData();
return () => controller.abort();
}, [movieId]);
return [state, loading, error];
}
I started having fun with custom hooks recently. I am mostly using them to fetch from api. The thing is that since I cannot really put useFetchLink inside of functions or useEffect i dont know how to prevent it from fetching after website first render. I could put some ifs in the hook but isn't there any other way?
***component***
export default function LinkShortener({ setLinkArr }) {
const [nextLink, setNextLink] = useState();
const inputRef = useRef(null);
const handleClick = () => {
setNextLink(inputRef.current.value);
};
const { shortLink, loading, error } = useFetchLink(nextLink);
useEffect(() => {
setLinkArr((prev) => [
...prev,
{
id: prev.length === 0 ? 1 : prev[prev.length - 1].id + 1,
long: nextLink,
short: shortLink,
},
]);
inputRef.current.value = "";
}, [shortLink, error]);
return (
<LinkShortenerContainer>
<InputContainer>
<LinkInput ref={inputRef} type="text" />
</InputContainer>
<Button
size={buttonSize.medium}
text={
loading ? (
<Loader />
) : (
<FormattedMessage
id="linkShortener.shortenItBtn"
defaultMessage="Shorten It !"
/>
)
}
onClick={handleClick}
></Button>
</LinkShortenerContainer>
);
}
***hook***
const useFetchLink = (linkToShorten) => {
const [shortLink, setShortLink] = useState("");
const [loading, setLoading] = useState(false);
const [error, setError] = useState("");
const fetchLink = async () => {
setLoading(true);
try {
const response = await fetch(
`https://api.shrtco.de/v2/shorten?url=${linkToShorten}`
);
if (response.ok) {
const data = await response.json();
setShortLink(data.result.short_link);
} else {
throw response.status;
}
} catch (err) {
setError(err);
} finally {
setLoading(false);
}
};
useEffect(() => {
fetchLink(linkToShorten);
}, [linkToShorten]);
const value = { shortLink, loading, error };
return value;
};```
Why not using directly fetchLink function and calling it whenever you need inside the component? I would change the hook in this way without useEffect inside
const useFetchLink = (linkToShorten) => {
const [shortLink, setShortLink] = useState("");
const [loading, setLoading] = useState(false);
const [error, setError] = useState("");
const fetchLink = async () => {
setLoading(true);
try {
const response = await fetch(
`https://api.shrtco.de/v2/shorten?url=${linkToShorten}`
);
if (response.ok) {
const data = await response.json();
setShortLink(data.result.short_link);
} else {
throw response.status;
}
} catch (err) {
setError(err);
} finally {
setLoading(false);
}
};
const value = { shortLink, loading, error, fetchLink };
return value;
};
Generally speaking - the standard way to avoid useEffect from running of 1st render is to use a boolean ref initialized with false, and toggled to true after first render - see this answer.
However, in your case, you don't want to call the function if linkToShorten is empty, even if it's not the 1st render, so use an if inside useEffect.
const useFetchLink = (linkToShorten) => {
const [shortLink, setShortLink] = useState("");
const [loading, setLoading] = useState(false);
const [error, setError] = useState("");
const fetchLink = useCallback(async (linkToShorten) => {
setLoading(true);
try {
const response = await fetch(
`https://api.shrtco.de/v2/shorten?url=${linkToShorten}`
);
if (response.ok) {
const data = await response.json();
setShortLink(data.result.short_link);
} else {
throw response.status;
}
} catch (err) {
setError(err);
} finally {
setLoading(false);
}
}, []);
useEffect(() => {
if(linkToShorten) fetchLink(linkToShorten);
}, [fetchLink, linkToShorten]);
const value = { shortLink, loading, error };
return value;
};
I created a custom hook which I use in App.js
The custom hook (relevant function is fetchTasks):
export default function useFetch() {
const [loading, setLoading] = useState(false);
const [error, setError] = useState(false);
const [tasks, setTasks] = useState([]);
const fetchTasks = async (url) => {
setLoading(true);
setError(null);
try {
const response = await fetch(url);
if (!response.ok) {
throw new Error("falied!");
}
const data = await response.json();
const loadedTasks = [];
for (const taskKey in data) {
loadedTasks.push({ id: taskKey, text: data[taskKey].text });
}
setTasks(loadedTasks);
} catch (err) {
console.log(err.message);
}
setLoading(false);
};
return {
loading,
setLoading,
error,
setError,
fetchTasks,
tasks,
};
}
Then in my App.js:
function App() {
const { loading, setLoading, error, setError, fetchTasks, tasks } =
useFetch();
useEffect(() => {
console.log("fetching");
fetchTasks(
"https://.....firebaseio.com/tasks.json"
);
}, []);
My IDE suggests adding the fetchTasks function as a dependency to useEffect. But once I add it, an infinite loop is created. If I omit it from the dependencies as shown in my code, it will work as expected, but I know this is a bad practice. What should I do then?
Because that every time you call useFetch(). fetchTasks function will be re-created. That cause the reference to change at every render then useEffect() will detected that dependency fetchTasks is re-created and execute it again, and make the infinite loop.
So you can leverage useCallback() to memoize your fetchTasks() function so the reference will remains unchanged.
import { useCallback } from 'react'
export default function useFetch() {
const [loading, setLoading] = useState(false);
const [error, setError] = useState(false);
const [tasks, setTasks] = useState([]);
const fetchTasks = useCallback(
async (url) => {
setLoading(true);
setError(null);
try {
const response = await fetch(url);
if (!response.ok) {
throw new Error("falied!");
}
const data = await response.json();
const loadedTasks = [];
for (const taskKey in data) {
loadedTasks.push({ id: taskKey, text: data[taskKey].text });
}
setTasks(loadedTasks);
} catch (err) {
console.log(err.message);
}
setLoading(false);
};,[])
return {
loading,
setLoading,
error,
setError,
fetchTasks,
tasks,
};
}
function App() {
const { loading, setLoading, error, setError, fetchTasks, tasks } =
useFetch();
useEffect(() => {
console.log("fetching");
fetchTasks(
"https://.....firebaseio.com/tasks.json"
);
}, [fetchTasks]);
instead of return fetchTasks function return this useCallback fetchTasksCallback function from useFetch hook which created only one instance of fetchTasksCallback.
const fetchTasksCallback = useCallback(
(url) => {
fetchTasks(url);
},
[],
);
function App() {
const { loading, setLoading, error, setError, fetchTasksCallback, tasks } =
useFetch();
useEffect(() => {
console.log("fetching");
fetchTasksCallback(
"https://.....firebaseio.com/tasks.json"
);
}, [fetchTasksCallback]);
the problem is this fetchTasks every time create a new instance that way dependency list feels that there is a change and repeats the useEffect code block which causes the infinite loop problem
I have a custom hook to make async calls with setting errors, loadings etc.
import { useEffect, useState } from 'react';
const useMakeAsyncCall = ({ asyncFunctionToRun = null, runOnMount = false }) => {
const [response, setResponse] = useState(null);
const [error, setError] = useState('');
const [loading, setLoading] = useState(false);
const fetchData = async () => {
setLoading(true);
try {
const res = await asyncFunctionToRun();
const json = await res.json();
setResponse(json);
setLoading(false);
} catch (error) {
setError(error);
setLoading(false);
}
};
useEffect(() => {
if (runOnMount && asyncFunctionToRun !== null) fetchData();
// eslint-disable-next-line react-hooks/exhaustive-deps
}, [runOnMount]);
return { response, error, loading, fetchData };
};
export default useMakeAsyncCall;
In component I am using it like this
const { error, isLoading, fetchData } = useMakeAsyncCall({
asyncFunctionToRun: () => signUpUser(),
runOnMount: false,
});
const signUpUser = () => {
...some requests to firebase
};
const handleSumbit = (e) => {
e.preventDefault();
fetchData();
};
Now I am trying to test this logic.
it('does things', async () => {
const { container, getByTestId } = render(<Component/>);
const form = getByTestId('form');
fireEvent.submit(form);
expect(container.firstChild).toMatchSnapshot();
});
And I'm getting this error Warning: An update to Component inside a test was not wrapped in act(...) and it is pointing to setError and setLoading inside my hook. How to go about fixing it and testing this functionality?
Here's my file:
// useFetcher.js
import { useEffect, useState } from "react";
export default function useFetcher(action) {
const [loading, setLoading] = useState(false);
const [error, setError] = useState(null);
const [data, setData] = useState(null);
async function loadData() {
try {
setLoading(true);
const actionData = await action();
setData(actionData);
} catch (e) {
setError(e);
} finally {
setLoading(false);
}
}
useEffect(() => {
loadData();
}, [action]);
return [data, loading, error];
}
On line 21, eslint complaints that:
React Hook useEffect has a missing dependency: 'loadData'. Either include it or remove the dependency array.eslint(react-hooks/exhaustive-deps)
How can I fix this?
The best way here would be to define your async function inside the useEffect:
export default function useFetcher(action) {
const [loading, setLoading] = useState(false);
const [error, setError] = useState(null);
const [data, setData] = useState(null);
useEffect(() => {
async function loadData() {
try {
setLoading(true);
const actionData = await action();
setData(actionData);
} catch (e) {
setError(e);
} finally {
setLoading(false);
}
}
loadData();
}, [action]);
return [data, loading, error];
}
More info in the docs.
Add the loadData function to the array in your useEffect. This will get rid of the complaint:
useEffect(() => {
loadData();
}, [action, loadData]);