I am trying to call an async function in a customer flatlist view, but I am get errors caused by using await in the custom flatlist view:
async _customFlatlistView(item){
promise = await SomeFunction();
promise2 = await SomeOtherFunction();
}
await can only be used in async functions
_customFlatlistView = async item => {
promise = await SomeFunction()
promise2 = await SomeOtherFunction()
}
The await keyword can only be used in adding the async keyword to the method signature:
async _customFlatlistView(item){
promise = await SomeFunction();
promise2 = await SomeOtherFunction();
}
Related
I'm getting this error:
A call to an async function is not awaited. Use the "await" keyword
before actions, assertions or chains of them to ensure that they run
in the right sequence.
But I am using an await within my code, what am I doing incorrectly?
test("Accepts the cookie", async t => {
const interfaceSelect = Selector('#sp_message_iframe_617100');
await
t.switchToIframe('#sp_message_iframe_617100')
t.click(Selector('button').withText('Accept'))
t.switchToIframe('#select_region-select-module_select_30IZf')
const countrySelect = Selector('#region-select-module_select__30lZf');
t.click(Selector('button').withText('United Kingdom'))
});
Thanks,
The TestCafe's methods are chainable and return a Promise.
You need to add an await before each method call or one await before the whole chain.
test("Accepts the cookie", async t => {
const interfaceSelect = Selector('#sp_message_iframe_617100');
await t.switchToIframe('#sp_message_iframe_617100');
await t.click(Selector('button').withText('Accept'));
await t.switchToIframe('#select_region-select-module_select_30IZf');
const countrySelect = Selector('#region-select-module_select__30lZf');
await t.click(Selector('button').withText('United Kingdom'));
});
test("Accepts the cookie", async t => {
const interfaceSelect = Selector('#sp_message_iframe_617100');
await t
.switchToIframe('#sp_message_iframe_617100')
.click(Selector('button').withText('Accept'))
.switchToIframe('#select_region-select-module_select_30IZf');
const countrySelect = Selector('#region-select-module_select__30lZf');
await t.click(Selector('button').withText('United Kingdom'));
});
I know I have to use then() or in a async function to use await to get the value from other async function .
but how to I get value directly ?
I try to pass the value in normal function but not work .
there is no other way to get the value directly ?
thanks
here is ample :
load_data_normal(key){
this.load_data(key).then((ret_val)=>{
console.log(ret_val);
return ret_val;
})
}
load_data = async (key) => {
const MMM = await AsyncStorage.getItem(key);
return MMM;
}
load_data function just work with then(), but load_data_normal not work ,
I just want to get value from get_data without then ..
The simple solution is just adding async to your load_data_normal, if you want to know more read this https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise
load_data_normal = async (key) => {
const ret_val = await this.load_data(key);
return ret_val;
}
load_data = async (key) => {
const MMM = await AsyncStorage.getItem(key);
return MMM;
}
Normal function doesn't work with await. You need an async function.
const asynFunction = async() => {
const results = await fetch(url);
console.log('results', results)
}
If you don't want to use async, you need to create a new promise.
const load_data_normal = (key) => {
localStorage.setItem("abc", "somevalue in abc");
load_data(key).then((resuls) => {
console.log("abc", resuls);
});
};
const load_data = (someKey) => {
return new Promise((resolve) => resolve(localStorage.getItem(someKey)));
};
load_data_normal("abc");
Sandbox
I have an async function that calls AsyncStorage.getItem but always returns a promise.
I tried to use .then clause but the result is similar
I tried to use AsyncStorage.getItem out of the function but I get the error "await is a reserved word"
getDataStorage = async () => {
console.log("getDataStorage");
var data = '';
try {
data = await AsyncStorage.getItem('dataStorage');
console.log("getting data " + data);
return data;
} catch (error) {
console.log("----" + error.message);
}
};
componentDidMount(){
console.log("componentDidMount");
var data = this.getDataStorage();
console.log(data);
}
The result is first displays the promise then prints the value that I get with getItem().
I want to get the value, I suppose with await the function waits for the result of getItem, is it correct?
Yes, await functions wait for the result. But, in your case its only waiting till returning promise, so you have to change your code as:
componentDidMount = async () => {
console.log("componentDidMount");
data = await this.getDataStorage();
console.log(data);
}
I need to display in my html variable: {my_dates}. The problem that I can't get it work with fetch but can do with old ajax request.
not working code:
created: function(){
//this.getTableData()
url = 'http://dlang.ru/test'
async function fetchAsync () {
const response = await fetch(url);
return await response.json();
}
this.my_dates = fetchAsync();
}
Working code:
$.ajax({
url: "http://dlang.ru/test",
success: function (data) {
Vue.set(app, "my_dates", data);
app.show = true;
}
});
If you want to be able to assign result of fetchAsync() to this.my_dates then entire created hook method needs to be declared as async.
Then you also need await in front of fetchAsync call:
created: async function () {
const url = 'http://dlang.ru/test';
async function fetchAsync() {
const response = await fetch(url);
return await response.json();
}
this.my_dates = await fetchAsync();
}
Please try this:
created: function(){
//this.getTableData()
url = 'http://dlang.ru/test'
async function fetchAsync () {
const response = await fetch(url);
const data = await response.json();
Vue.set(app, "my_dates", data);
app.show = true;
}
fetchAsync();
}
I want to access my token from ACCESS_TOKEN . and merge to my URL.
async getToken(){
try{
var token = await AsyncStorage.getItem('ACCESS_TOKEN')
}catch(error){}
return token;
};
componentDidMount(){
var v = this.getToken()
Alert.alert(v)
return fetch('http://localhost/'+v);
}
I get the error in the output.
com.facebook.react.bridge.ReadableNativeMap cannot be casst to java.lang.string
You need the async and await in componentDidMount as well as getToken returns a promise (as with all functions declare with async).
async componentDidMount() {
let v = await this.getToken();