await is giving Refrence error in react-native - react-native

Question

I have the following code
async _onPress() {
NetInfo.isConnected.fetch().then(isConnected => {
if (isConnected) {
fetch(apiURL + '/login', {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({
username: this.props.username,
password: this.props.password
})
})
.then((response) => response.json())
.then((responseJson) => {
if (responseJson.status === 'success')
//I am getting error here
await AsyncStorage.setItem('token', responseJson.token);
//moving on to the main screen if server return success
Actions.MainScreen();
} else {
Toast.show({
text: "Wrong username or password!",
type: "danger"
});
}
})
.catch((error) => {
console.log(error);
});
} else {
Toast.show({
text: "Please Connect To Internet",
type: "danger"
});
}
});
}
I am trying to save the token i receive from my API server using AsyncStorage.I get the following errors
Expression statement is not assignmentor call
and RefrenceError:await is not defined
when i try to use await in the location.
But when use the same code at the beginning of the function i get no errors.
I dont know what is wrong. Is it not allowed in async await? I am not too familiar with these.

Answer 1

If _onPress calls some async functions and you want to wait for all of them to finish, you must place an 'await' in front of every single one of them. In addition, every async function, including async callback functions, must be declared async too.
The complete code:
async _onPress() {
**await** NetInfo.isConnected.fetch().then(**async** (isConnected) => {
if (isConnected) {
**await** fetch(apiURL + '/login', {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({
username: this.props.username,
password: this.props.password
})
})
.then((response) => response.json())
.then(**async** (responseJson) => {
if (responseJson.status === 'success') {
**await** AsyncStorage.setItem('token', responseJson.token);
Actions.MainScreen();
} else {
Toast.show({
text: "Wrong username or password!",
type: "danger"
});
}
})
}
})
}