I have a list of companies in React Native.
When I click on one of those companies I get the url of the API that is used for selected company. Then I store it to AsyncStorage and then I show the login screen. The function is as follows:
selectCompany(data_url, e) {
AsyncStorage.setItem("data_url", JSON.stringify(data_url), () => this.props.login());
}
Then on login page if I click on sign in button I go to the onLogin function, the function is as follows:
onLogin: function() {
fetch(data.url + '/manager/api/v1/obtain-auth-token/', })
.then(function(body) {
return body.json();
}).then(function(json) {
.....
}).catch(function() {
....
});
},
And data.url comes from data.js file, and I try to get url from the data.js file as follows:
let data_url = AsyncStorage.getItem("data_url").then(json => JSON.parse(json));
module.exports = {
url: data_url,
.....
}
But it doesn't work. Any advice?
AsyncStorage is async, therefore data_url will not be defined until it's retrieved what its looking for, you would need to move the fetch into the promise thats returned from the get so it will run it once it's done getting the data. This might be one way you tackle it:
const data_url = () => AsyncStorage.getItem("data_url"); //change this into a function
module.exports = {
url: data_url,
.....
}
now inside your component...
onLogin: function() {
data.url().then((url) => {
fetch(JSON.parse(url) + '/manager/api/v1/obtain-auth-token/', })
.then(function(body) {
return body.json();
}).then(function(json) {
.....
}).catch(function() {
....
});
});
},
AsyncStorage.getItem is a promise and needs to await for response rather than accessing direct and the function calling it should be defined as async. Here is an example to retrieve from AsyncStorage..
export async function getAccessKey(){
let accessToken = await AsyncStorage.getItem(ACCESS_TOKEN);
return accessToken;
}
Related
Im working with my friends on a app project and we find an issue many times when we tring to set a use state and the console log the variable, i've looking for a solution in the website and saw that the reason is that the usestate is an async awiat which means the variable that i set in the use state isn't immidatly set in it, so i tried many solution that i found in the websites but none of them work for me.
in the screenShot you can see that the json variable is in console log before and the set varaible doesn't show after the setActiveUser , any help?
Thanks!
If you want to do something upon setting state then your best bet is to use the useEffect hook from React and adding your state in the dependency array. This will then call the function in your useEffect every time the state changes. See below a rough example:
import { Text } from 'react-native';
const MyComponent = () => {
const [activeUser, setActiveUser] = useState(null);
useEffect(() => {
// This should log every time activeUser changes
console.log({ activeUser });
}, [activeUser]);
const fetchAuthentication = async user => {
var flag = false;
await fetch('/api/authUser/', {
method: 'PUT',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify(user),
})
.then(res => {
res.ok && (flag = true);
return res.json();
})
.then(json => {
if (flag) {
setActiveUser(json);
}
})
.catch(error => console.error(error));
return flag;
};
return <Text>Hi</Text>;
};
Full documentation: https://reactjs.org/docs/hooks-effect.html
I am using an api call to get information for my app which I display to the user. The problem is that when I open the screen for the first time the app displays the information but when I go to a different screen and then comeback I dont see the information unless I restart the app.
This function makes the apiCall for me:
async function getOrders() {
var retrieveData = async () => {
try {
var value = await AsyncStorage.getItem("user");
var data = JSON.parse(value);
return data.user.email;
} catch (error) {
alert(error);
}
};
retrieveData().then((usr) => {
setUser(usr)
fetch(URL + "/api/order/quoted", {
method: "POST",
body: "user=" + usr,
headers: { "Content-type": "application/x-www-form-urlencoded" },
})
.then((response) => response.json())
.then((responseJson) => {
if (responseJson.error === null) {
setOrders(responseJson.orders);
}
});
});
}
First I use the retriveData function to get the used id, based on that information is server to the user.
You are using react-navigation version 5, so you need to wrap your logic fetch data in useFocusEffect hook react navigation docs
import { useFocusEffect } from '#react-navigation/native';
useFocusEffect(
React.useCallback(() => {
getOrders()
}, [getOrders])
);
The problem can be solved in the following steps:
If you want the data fetched from your endpoint to be used even if you move to other screen use Redux.
If you use redux or not and want to fetch the api every time you open a specific screen then you need to add an onfocus listener. An example is here https://reactnavigation.org/docs/navigation-events/
class Profile extends React.Component {
componentDidMount() {
this._unsubscribe = navigation.addListener('focus', () => {
// do something
});
}
My problem is that when I go from one user page to another user page the info in component still remains from first user. So if I go from /user/username1 to /user/username2 info remains from username1. How can I fix this ? This is my code:
UserProfile.vue
mounted() {
this.$store.dispatch('getUserProfile').then(data => {
if(data.success = true) {
this.username = data.user.username;
this.positive = data.user.positiverep;
this.negative = data.user.negativerep;
this.createdAt = data.user.createdAt;
this.lastLogin = data.user.lastLogin;
data.invites.forEach(element => {
this.invites.push(element);
});
}
});
},
And this is from actions.js file to get user:
const getUserProfile = async ({
commit
}) => {
try {
const response = await API.get('/user/' + router.currentRoute.params.username);
if (response.status === 200 && response.data.user) {
const data = {
success: true,
user: response.data.user,
invites: response.data.invites
}
return data;
} else {
return console.log('Something went wrong.');
}
} catch (error) {
console.log(error);
}
};
Should I add watch maybe instead of mounted to keep track of username change in url ?
You can use watch with the immediate property, you can then remove the code in mounted as the watch handler will be called instead.
watch: {
'$route.params.username': {
handler: function() {
this.$store.dispatch('getUserProfile').then(data => {
if(data.success = true) {
this.username = data.user.username;
this.positive = data.user.positiverep;
this.negative = data.user.negativerep;
this.createdAt = data.user.createdAt;
this.lastLogin = data.user.lastLogin;
data.invites.forEach(element => {
this.invites.push(element);
});
}
});
},
deep: true,
immediate: true,
},
}
Your page is loaded before the data is retrieved it seems, you need put a "loading" property in the data and have a v-if="!loading" for your component then it will only render once the display is updated. Personally I would avoid watch if I can it is not great for performance of for fine grained handling.
Yes you should add wach on statement that contain user info.(you may have a problem to watch on object, so you can save user info in json, but im not sure). When user changing - call action, after recived response call mutation that should change a state, then watch this state.
And you might use better syntax to receive data from store. That is really bad idea call dispatch directly from your mouted hook, use vuex documentation to make your code better.
There is a form which submits some data to an API in my component. Assume that it's method is ProcessLogin(). Inside this function I have written my API calls using axios. With the help of then() I have handled my server response and displayed my toast. All good.
Now as a part of my code clean up, I have decided to move all my axios functions to another api.js file and export functions from there. Here is an example function I have in my api.js file :
function ApiLogin(data) {
const url = `${BASE_URL}/authenticate`;
axios.post(url,data).then(response => {
return response;
}).catch(error => {
return error.response;
});
}
On the other side in my component I have my method defined as below :
methods: {
ProcessLogin() {
var status = ApiLogin(this.data);
console.log(status);
}
}
When executing this, I get undefined on my console. I know why it is happening. Because console.log(status) executes before ApiLogin could process and sends it's response. How to handle this kind of situation.? I know that callback is the rescue here, but I am not really sure about how to integrate it.
If you return the axios call from your ApiLogin function:
function ApiLogin(data) {
const url = `${BASE_URL}/authenticate`
return axios.post(url, data)
}
You could then handle the response in your component using then and console log from there:
methods: {
ProcessLogin() {
ApiLogin(this.data)
.then(res => console.log(res))
.catch(err => console.log(err))
}
}
...or with async/await:
methods: {
ProcessLogin: async function() {
try {
var status = await ApiLogin(this.data)
console.log(status)
}
catch(err) {
console.log(err)
}
}
}
Good day. I have the following problem:
I have an item editor.
How it works: I push 'Add' button, fill some information, click 'Save' button.
_onSaveClicked function in my react component handles click event and call function from service, which sends params from edit form to server and return promise.
_onSaveClicked implements
.then(response => {
console.log('I\'m in then() block.');
console.log('response', response.data);
})
function and waits for promise result. It works in real situation.
I created fake service and placed it instead of real service.
Service's function contains:
return Promise.resolve({data: 'test response'});
As you can see fake service return resolved promise and .then() block should work immediatly. But .then() block never works.
Jest test:
jest.autoMockOff();
const React = require('react');
const ReactDOM = require('react-dom');
const TestUtils = require('react-addons-test-utils');
const expect = require('expect');
const TestService = require('./service/TestService ').default;
let testService = new TestService ();
describe('TestComponent', () => {
it('correct test component', () => {
//... some initial code here
let saveButton = TestUtils.findRenderedDOMComponentWithClass(editForm, 'btn-primary');
TestUtils.Simulate.click(saveButton);
// here I should see response in my console, but I don't
});
});
React component save function:
_onSaveClicked = (data) => {
this.context.testService.saveData(data)
.then(response => {
console.log('I\'m in then() block.');
console.log('response', response.data);
});
};
Service:
export default class TestService {
saveData = (data) => {
console.log('I\'m in services saveData function');
return Promise.resolve({data: data});
};
}
I see only "I'm in services saveData function" in my console.
How to make it works? I need to immitate server response.
Thank you for your time.
You can wrap your testing component in another one like:
class ContextInitContainer extends React.Component {
static childContextTypes = {
testService: React.PropTypes.object
};
getChildContext = () => {
return {
testService: {
saveData: (data) => {
return {
then: function(callback) {
return callback({
// here should be your response body object
})
}
}
}
}
};
};
render() {
return this.props.children;
}
}
then:
<ContextInitContainer>
<YourTestingComponent />
</ContextInitContainer>
So your promise will be executed immediately.