I’m using 2 usestate in my component
const [choosedH, setChoosedH] = useState([]);
const [h, setH] = useState([]);
I have async method which fetch data from api and convert it to final array.
useEffect(() => {
getH();
}, [])
async function getH(){
const username = await SecureStore.getItemAsync('username')
const token = await SecureStore.getItemAsync('token')
axiosInstance.get('/api/xxx/' + username,
{
headers: {
Cookie: token,
},
},
{ withCredentials: true }
)
.then((response) => {
if(response.data.length > 0){
let singleH = {};
response.data.forEach(element => {
singleH = {
label: element.name,
value: element.name
}
h.push(singleH);
});
console.log(h)
}
})
.catch(function (error) {
console.log('There has been a problem with your fetch operation: ' + error.message);
throw error;
})
}
and finally i have my component:
<RNPickerSelect
onValueChange={(value) => setChoosedH(value)}
items={h}
useNativeAndroidPickerStyle={false}
style={{
...pickerSelectStyles,
iconContainer: {
top: 10,
right: 10,
},
}}
placeholder={{
label: 'Select',
value: null,
}}
Icon={() => {
return <Icon name="arrow-down" size={24} />;
}}
value={choosedH}
/>
I have a problem. After render my picker contain empty array. When render end, hook useEffect call getH() which give me data from api and convert it as I want to value of useState "h". How to force update picker items when function getH will end? It it possible to get data from api before render? Any ideas ?
>Solution :
I guess the problem is that you try to access h directly instead of using setH.
This should work:
if(response.data.length > 0){
const myArray = []
response.data.forEach(element => {
const singleH = {
label: element.name,
value: element.name
}
myArray.push(singleH);
});
setH(myArray)
console.log(h)
}