Here I have a promise inside refresh control method,
const Component = () => {
const [refreshing, setRefreshing] = useState(false);
const onRefresh = useCallback(() => {
setRefreshing(true);
getData();
setRefreshing(false);
}, []);
return (
<ScrollView
refreshControl={
<RefreshControl refreshing={refreshing} onRefresh={onRefresh} />
}>...</ScrollView>
);
}
How to wait for the getData() function and after that set refresh to false? Problem is it isn't waiting for the getData() function to finish. (getData() is a promise)
the getData() function,
const getData = () => {
axios.get(`https://somedomain.com/fetch/user/1`).then(res => {
...
}
}
const Component = () => {
const [refreshing, setRefreshing] = useState(false);
const getData = () => {
axios.get(`https://somedomain.com/fetch/user/1`).then(res => {
...
setRefreshing(false);
}
}
const onRefresh = useCallback(() => {
setRefreshing(true);
getData();
}, []);
return (
<ScrollView
refreshControl={
<RefreshControl refreshing={refreshing} onRefresh={onRefresh} />
}>...</ScrollView>
);
}
Alternative:
const getData = async () => {
const response = await axios.get(`https://somedomain.com/fetch/user/1`);
//Handle your response here
}
const onRefresh = useCallback(async () => {
setRefreshing(true);
await getData();
setRefreshing(false);
}, []);
getData() is a promise inside a function. In that method, I returned the promise and did like this to solve this issue,
const onRefresh = useCallback(async () => {
setRefreshing(true);
getData().then(() => {
setRefreshing(false);
});
}, []);
Related
this is a component that retrieve data from API and generate a table. One button in a column for removing the row opens a Modal.
For avoiding in first component render to trigger api.delete request, an useRef set as false in second useEffect
Modal's Delete button return row info in deleteHandler function which successfully trigger api.delete request on confirmation, remove user in backend however table is not reloading.
Once row is removed expected result is triggering api.get request and display table now updated and without row removed.
In order to get that result I tried with const [reload, setReload] = useState(false); state which introduce another dependency to both userEffect
reload state effectively reload table data updated however it cause also that api.delete request trigger with const ida undefined. Below component script it can find useEffect with my tried.
Any hint or possible solution is appreciated
import React, { Fragment, useEffect, useState, useRef } from "react";
... other imports ...
export default function AllUsers() {
const api = useApi();
const [userData, setUserData] = useState();
const [showModal, setShowModal] = useState(false);
const navigate = useNavigate();
const [modalMessage, setModalMessage] = useState();
const [removeUserId, setRemoveUserId] = useState();
const [ida, setIda] = useState();
let effectRan = useRef(false);
const [reload, setReload] = useState(false);
useEffect(() => {
(async () => {
const response = await api.get("/admin/users");
if (response.ok) {
setUserData(response.body);
} else {
setUserData(null);
}
})();
}, [api]);
useEffect(() => {
if (effectRan.current) {
// console.log("effect run");
(async () => {
const response = await api.delete("/admin/users", {
ida: ida,
});
if (response.ok && response.status === 204) {
console.log(response);
} else {
console.log(response.body.errors);
}
})();
}
return () => (effectRan.current = true);
}, [api, ida]);
const handleEditClick = (e, rowIndex) => {
// console.log("user/" + rowIndex.username);
navigate("/user/" + rowIndex.username, [navigate]);
};
const handleRemoveClick = (e, rowIndex) => {
// console.log([rowIndex]);
setShowModal(true);
setModalMessage({
title: `Remove ${rowIndex.username}`,
message: `User's email to remove ${rowIndex.email}`,
});
setRemoveUserId(rowIndex.id);
};
const closeHandler = () => {
setShowModal(false);
};
const deleteHandler = () => {
// console.log(removeUserId);
setIda(removeUserId);
setShowModal(false);
};
// console.log(ida, idb);
return (
<Fragment>
{showModal && (
<BtModal
show={showModal}
title={modalMessage.title}
message={modalMessage.message}
handleClose={closeHandler}
onConfirm={deleteHandler}
/>
)}
<Body>
<h1>User Table</h1>
{userData === undefined ? (
<Spinner animation="border" />
) : (
<>
{userData === null ? (
<p>Could not retrieve users.</p>
) : userData.length === 0 ? (
<p>There are not users in system</p>
) : (
<UserListTable
newData={userData}
handleEditClick={handleEditClick}
handleRemoveClick={handleRemoveClick}
/>
)}
</>
)}
</Body>
</Fragment>
);
}
useEffect updated with reload state:
useEffect(() => {
(async () => {
const response = await api.get("/admin/users");
if (response.ok) {
setUserData(response.body);
effectRan.current = false;
} else {
setUserData(null);
}
})();
}, [api, reload]);
useEffect(() => {
if (effectRan.current) {
// console.log("effect run");
(async () => {
const response = await api.delete("/admin/users", {
ida: ida,
});
if (response.ok && response.status === 204) {
console.log(response);
setReload(!reload);
} else {
console.log(response.body.errors);
}
})();
}
return () => (effectRan.current = true);
}, [api, ida, reload]);
Here you modify your last edit
const deleteHandler = () => {
// console.log(removeUserId);
setIda(removeUserId);
setReload(!reload)
setShowModal(false);
};
useEffect(() => {
(async () => {
const response = await api.get("/admin/users");
if (response.ok) {
setUserData(response.body);
} else {
setUserData(null);
}
})();
}, [api]);
useEffect(() => {
effectRan.current = reload;
if (effectRan.current) {
// console.log("effect run");
(async () => {
const response = await api.delete("/admin/users", {
ida: ida,
});
if (response.ok && response.status === 204) {
console.log(response);
setReload(!reload);
} else {
console.log(response.body.errors);
}
})();
}
return () => {
effectRan.current = false;
};
}, [api, ida, reload]);
It looks like you're trying to delete an item in the table and confirm it via a prompt. I can see that you've used a lot of useEffects, which might be making things a bit complicated.
Don't worry though, I have a solution that should be much simpler. Let me show you what I mean!
const Page = () => {
const [data, setData] = useState([]);
const [loading, setLoading] = useState([]);
const [deleting, setDeleting] = useState(false);
const [selectedItem, setSelectedItem] = useState(null);
const deleteHandler = async() => {
setDeleting(true);
await api.delete(selectedItem);
// Next you can either update the state itself
let tD = [...data];
const index = tD.findIndex((i) => i.id == selectedItem);
tD.splice(index, 1);
setSelectedItem(tD);
// or refetch data from the backend and update the state
const d = await api.getData();
setData(d);
setDeleting(false);
setSelectedItem(null);
};
useEffect(() => {
const fetchData = async() => {
setLoading(true);
const d = await api.getData();
setData(d);
setLoading(false);
}
fetchData();
}, [])
return loading ? <div>Loading...</div> : <>
{/*Other JSX elements*/}
{selectedItem && <div>
{/*prompt body*/}
<button onClick={() => {setSelectedItem(null)}}>Cancel</button>
<button disabled={deleting} onClick={() => {deleteHandler()}}>Delete</button>
{/*Button will be disabled when the DELETE request is sent*/}
</div>}
{data.map((row) => {
return <tr key={row.id}>
<td>...</td>
<td>...</td>
<td>
<button onClick={setSelectedItem(row.id)}>Delete</button>
</td>
</tr>
})}
</>
}
I have this simple react native app that on button click it redirects user to a page. I'm saving data in a cache so that if user clicks the store button it stores data and after refresh it sets store data. However, I would like to implement this logic on a single button, not on 2 different buttons as it is now. Can someone explain me how could I achieve this?
export const App = () => {
const [showFirstWeb, setFirstWeb] = useState(false);
const getData = async () => {
try {
const jsonValue = await AsyncStorage.getItem("#web_Key");
return setFirstWeb(JSON.parse(jsonValue));
} catch (e) {
console.log("error", e);
}
};
useEffect(() => getData, []);
const storeData = async () => {
try {
const jsonValue = JSON.stringify(showFirstWeb);
await AsyncStorage.setItem("#web_Key", jsonValue);
} catch (e) {
console.log("error", e);
}
};
return (
<View>
<View style={styles.buttonStyle}>
<Button onPress={setFirstWeb(!showFirstWeb)}/>
<Button onPress={storeData} title="store"/>
<View>
{showFirstWeb && <MyWebComponent uri="https://www.google.com/" />}
</View>
</View>
);
};
const MyWebComponent = (uri) => {
return <WebView source={uri} />;
};```
export const App = () => {
const [showFirstWeb, setFirstWeb] = useState(false);
const getData = async () => {
try {
const jsonValue = await AsyncStorage.getItem("#web_Key");
return setFirstWeb(JSON.parse(jsonValue));
} catch (e) {
console.log("error", e);
}
};
// you forgot to call the function here
useEffect(() => getData(), []);
const storeData = async () => {
try {
// get the new value
const newShowFirstWeb = !showFirstWeb
// use the new value
setFirstWeb(newShowFirstWeb)
const jsonValue = JSON.stringify(newShowFirstWeb );
await AsyncStorage.setItem("#web_Key", jsonValue);
} catch (e) {
console.log("error", e);
}
};
return (
<View>
<View style={styles.buttonStyle}>
<Button onPress={storeData} title="store"/>
<View>
{showFirstWeb && <MyWebComponent uri="https://www.google.com/" />}
</View>
</View>
);
};
I'm working on implementing a braintree payment method in my react/mui app. I've found a way that works, but it's in a class component. How can I convert this info a proper functional component?
const BraintreeDropInPaymentMethod = () => {
class Store extends React.Component {
instance;
state = {
clientToken: '<BRAIN TREE KEY>'
};
async componentDidMount() {
const response = await fetch("server.test/client_token");
const clientToken = await response.json();
this.setState({
clientToken,
});
}
async buy() {
const { nonce } = await this.instance.requestPaymentMethod();
await fetch(`server.test/purchase/${nonce}`);
}
render() {
if (!this.state.clientToken) {
return (
<div>
<h1>Loading...</h1>
</div>
);
} else {
return (
<div>
<DropIn
options={{ authorization: this.state.clientToken }}
onInstance={(instance) => (this.instance = instance)}
/>
<Button
variant='contained'
onClick={this.buy.bind(this)}
>
Create Account
</Button>
<Button
variant='outlined'
sx={{ marginLeft: 3 }}
color='warning'
onClick={(e) => handleCancelAccountCreation(e)}
href='/store-front'
>
Cancel
</Button>
</div>
);
}
}
}
const [user, setUser] = useState({})
const handleCancelAccountCreation = (event) => {
setUser({})
document.getElementById('signInBtn').hidden = false
}
return (
<Store/>
)
}
this is my attempt, but I'm coming up short on how I should handle componentDidMount(). I know how to handle useState in some situations, except for this one. Also, how can I handle the 'instance' section in a functional format? thanks.
const BraintreeDropInPaymentMethod = () => {
const [token, setToken] = useState('<BRAIN TREE KEY>')
const [user, setUser] = useState({})
const contactServer = async () => {
const res = await fetch('server.test/client_token')
const clientToken = await res.json()
console.log(clientToken)
setToken(token)
}
const buy = async () => {
const { nonce } = await this.instance.requestPaymentMethod()
await fetch(`server.test/purchase/${nonce}`)
}
const handleCancelAccountCreation = (event) => {
setUser({})
document.getElementById('signInBtn').hidden = false
}
const createAccountOptions = () => {
if (!token) {
return (
<div>
<h1>Loading...</h1>
</div>
) else {
return (
<div>
<DropIn
options={ authorization: {setToken})
onInstance={(instance) => (this.instance = instance)}
/>
<Button
variant="contained'
onClick={buy}
>
Create Account
</Button
variant='outlined'
sx={{ marginLeft: 3 }}
color='warning'
onClick={(e) => handleCancelAccountCreation(e)}
href='/store-front'
>
<Button>
Cancel
</Button>
</div>
)
}
}
}
return(
<>
<createAccountOptions/>
</>
)
}
The functional equivalent of componentDidMount() is the useEffect hook.
In this case you would change this:
async componentDidMount() {
const response = await fetch("server.test/client_token");
const clientToken = await response.json();
this.setState({
clientToken,
});
}
Into something like this:
useEffect(() => {
fetchData();
}, []);
const fetchData = async () => {
const response = await fetch("server.test/client_token");
const clientToken = await response.json();
setState((old) => clientToken);
};
Using the useEffect hook with an empty array as a dependency makes the function in it only run once as the component mounts.
I have an api (an arr of objects) which I need to pass into a state, so that I can then pass that data inside a component to show it on the website.
1st approach:
// pulls the api data
const newData = axios.get(url).then((resp) => {
const apiData = resp.data;
apiData.map((video) => {
return video;
});
});
// sets the state for the video
const [selectedVideo, setSelectedVideo] = useState(newData[0]);
const [videos] = useState(videoDetailsData);
...
return (
<>
<FeaturedVideoDescription selectedVideo={selectedVideo} />
</>
)
2nd approach:
const useAxiosUrl = () => {
const [selectedVideo, setSelectedVideo] = useState(null);
useEffect(() => {
axios
.get(url)
.then((resp) => setSelectedVideo(resp.data))
});
return selectedVideo;
}
...
return (
<>
<FeaturedVideoDescription selectedVideo={selectedVideo} />
</>
)
both of these approaches don't seem to work. What am I missing here?
The correct way is to call your axios method inside the useEffect function.
const fetchData = axios.get(url).then((resp) => setSelectedVideo(resp.data)));
useEffect(() => {
fetchData();
}, [])
or if you need async/await
useEffect(() => {
const fetchData = async () => {
const response = await axios.get(url);
setSelectedVideo(resp.data);
}
fetchData();
}, [])
I have multiple component which has state change during its data collection from get api call, are called from a single component get re-render multiple times , Please help to avoid re-render when open this page
const MyData = () => {
const [data, setData] = useState("");
const [newData, setNewData] = useState("");
const getData = () => {
axios.get("url").then(async function (response) {
setData(response);
});
};
const getData2 = () => {
axios.get("url").then(async function (response) {
setNewData(response);
});
};
useEffect(() => {
getData();
getData2();
});
const NewData = () => {
return (
<View>
<Text>{data.name}</Text>
</View>
);
};
const RewData = () => {
return (
<View>
<Text>{newData.name}</Text>
</View>
);
};
return (
<View>
<NewData />
<RewData />
</View>
);
};
You provide no dependency array (undefined) to your useEffect. If the component's state changes, then the useEffect will be called again, which sets the state again, and so on.
You can provide an empty dependency array which will cause the useEffect to be called only once.
useEffect(() => {
getData();
getData2();
}, []);
Edit: In response to the comments. You can prevent the screens content from rendering until the data has been fetched as follows.
const MyData = () => {
const [data, setData] = useState();
const [newData, setNewData] = useState();
const getData = () => {
axios.get("url").then(async function (response) {
setData(response);
});
};
const getData2 = () => {
axios.get("url").then(async function (response) {
setNewData(response);
});
};
useEffect(() => {
getData();
getData2();
}, []);
if (!data || !newData) {
return null
}
const NewData = () => {
return (
<View>
<Text>{data.name}</Text>
</View>
);
};
const RewData = () => {
return (
<View>
<Text>{newData.name}</Text>
</View>
);
};
return (
<View>
<NewData />
<RewData />
</View>
);
};