Develop Reference

axios interceptor - hold off the request until cookie API call is finished, and only then continue

I am trying to get the axios to wait until one extra call in the interceptor finishes. So I am using NuxtJS as a frontend SPA and API in Laravel 8.
I've tried a lot of different things over the course of last ~ 4 days but nothing seems to be working.
THE GOAL
I need my axios REQUEST interceptor to check for existence of the cookie. If cookie is not present I need to make an API call first to grab the cookie and then we can continue with any other request.
WHAT I AM DOING?
So basically I have Axios interceptor for the requests that will call cookie endpoint if the cookie doesn't exist.
I am also saving cookie request promise to be reused in case there are multiple calls and the cookie still is not there.
PROBLEM
While it was supposed to just call cookie API first and everything else after I am mostly getting two results in different variations of the attached code.
A) I am making an extra cookie call but it is not in the required order so I still end up hitting laravel endpoint multiple times without cookies which causes extra sessions to spawn.
B) It is not making any calls at all (attached example).
Does anyone know what in the world I am confusing here?
export default function ({$axios, redirect, $cookiz, store}) {
$axios.onRequest(async request => {
// make sure that XSRF cookie exists before we make aby calls to prevent backend from
// creating multiple session when page on load calls more than one endpoint, if we don't have
// that cookie we will first have to get it and then call the rest of the endpoints
const xsrfCookie = $cookiz.get('XSRF-TOKEN')
if (xsrfCookie === undefined || xsrfCookie === null || xsrfCookie === '') {
await store.dispatch('login/getXsrfCookie')
$axios.request(request)
}
$axios.request(request)
})
}
getXsrfCookie(context) {
if (context.state.xsrfCookiePromise instanceof Promise) {
return context.state.xsrfCookiePromise
}
const xsrfCookiePromise = this.$axios.get('/csrf-cookie').then(response => {
context.commit('setXsrfCookiePromise', null)
console.log('This is the cookie response', response)
})
context.commit('setXsrfCookiePromise', xsrfCookiePromise)
return context.state.xsrfCookiePromise
}

I don't know anything about nuxt, and have only a vague idea about axios interceptors, but just looking at the code...
I think you want to persist a cookie, not the promise for a cookie.
I don't think you need to involve the store.
I think you can do that with your cookie plugin. If I'm right about that, using the set method is what you need. (you might need an options param, described here)
async getXsrfCookie() {
if (!$cookiz.get('XSRF-TOKEN')) {
// the op should double check which part of the response to persist, whether to stringify it, etc.
const response = await this.$axios.get('/csrf-cookie');
$cookiz.set('XSRF-TOKEN', response.data);
}
}
export default function ({$axios, redirect, $cookiz, store}) {
$axios.onRequest(async request => {
await getXsrfCookie();
return $axios.request(request)
})
}

Why does a GET request with fetch API log a server response error message into the browser console?

I am using the fetch-API to send a GET request to a Spring Boot backend. The request looks somewhat like this:
const response = await fetch(url);
if (response.status === 200) {
// do something
} else {
response.json().then(response => console.log(response));
}
In case that I send a valid request, i.e. the url passed into fetch() is valid, everything works fine. In case that I pass an invalid url into fetch(), however, two things appear to be happenning:
A serer response message is thrown:
My Spring Boot backend return a ResponseEntity with a custom error message as body. This error message is logged inside the else-block of the above code snippet:
While I do expect the second point to be happenning, I cannot explain the first. I don't understand why this server-response error is logged into my browser console. I do have a few catch-blocks inside my code, something like:
const response = await fetch(url).catch(error => console.log(error));
As far as I know, however, fetch only throws an error if a network connection error occurred or similar. A response code not equal to 200 does not result in fetch throwing an error. So, as I said, I don't know where this error message comes from and I was hoping that somebody does, maybe it is something generic to the fetch API that I just don't know?

I recommend using "try catch" to better capture errors.
If the response is positive and it's a json, use a "then" after the fetch.
try {
const response = await fetch(url).then(res => res.json());
// do something
} catch (e) {
console.error(e);
}
If you're getting a 400 error, check the api documentation to see if you're passing the parameter incorrectly. or if that is not the route

ReactJS: how to make two backend requests at once?

Is it possible to make two backend requests at once from react?
The code below is the first backend call. The post request gets send to the backend and then I would like to do another request. Is it possible at all? Or do I have to wait for the backend response until the next request could be made?
What I basically want is to get information about how many files have been uploaded. The upload could take 3 minutes and the user right now only sees a loading icon. I want to additionally add a text like "50 of 800 Literatures uploaded" and 10 seconds later "100 of 800 litereratures uploaded".
This is basically my code :
class ProjectLiterature extends Component {
constructor(props) {
super(props);
this.state = {
isLoading:"false",
}
}
addLiterature(data, project_name) {
this.setState({ isLoading:true }, () => {
axios.post("http://127.0.0.1:5000/sendLiterature", data })
.then(res => {
this.setState({ isLoading: false })
})
})
}

If both requests do not depend on each other, you can make use of JavaScript's Promise.all() for the above purpose.
const request1 = axios.get('http://127.0.0.1:5000/sendLiterature');
const request2 = axios.get(url2);
Promise.all([request1,request2]).then([res1, res2] => {
// handle the rest
}).catch((error) => {
console.error(error);
// carry out error handling
});
If the second request relies on the response of the first request, you will have to wait for the first request to be completed as both requests have to be carried out in sequence.
const res = await axios.get('http://127.0.0.1:5000/sendLiterature');
// carry out the rest

You can see axios docs for this purpose, they support multiple requests out of box.
You can use Promise.all instead of axios.all as well but if one of requests fails then you won't be able to get response of successful calls. If you want get successful response even though some calls fails then you can use Promise.allSettled.

Data part of Response is a long script instead of desired json object

I am building a web app using laravel and vuejs. I have made a axios get request to get a list of users .
I am getting a Promise object, and from what i have read. Reason for getting a promise object is because it's an async request.
I have tried .then() to get data part of the response. But i am getting a huge script instead of desired data.
axios......then(function(response){
console.log(response.data);
})
Initially what i did was
var res = axios.get('/allUsers');
console.log(res)
That time i came to know about promise object and read about.
When i checked network in dev tools, status code is 200 and i can see list of users. So i guess my request is successfully completed.
What should be done to get the list of the users. That list i will be using to update my UI.

Depending on what you're getting back for data there are a few ways to handle this. You may need to convert the data after the you get receive the response.
axios.get('some_url')
.then(res => res.json())
.then(data => {
// do something with the data
}).catch(err) {
conosole.error(err);
}
if you're seeing the data come through properly in the response and you're getting what you need without doing that then just do
axios.get('some url').then(res => {
// do something in here with the data here
})
also make sure you're getting back json if that's what you're looking for. check your response to see if its html or json because they can be handled a bit differently
as an "Edit" you could also handle this with async await so you dont end up in callback hell
async function fetchData() {
try {
const res = await axios.get('some url');
// next step might not be necessary
const data = await res.json();
// do something with the data
console.log(data); // if converting it was necessary
console.log(res); // if not converting
} catch (err) {
console.error(err);
}
}

How can I make an asynchronous request (non-blocking) using a Cloudflare Worker

I'm writing a Cloudflare Worker that needs to ping an analytics service after my original request has completed. I don't want it to block the original request, as I don't want latency or a failure of the analytics system to slow down or break requests. How can I create a request which starts and ends after the original request completes?
addEventListener('fetch', event => {
event.respondWith(handle(event))
})
async function handle(event) {
const response = await fetch(event.request)
// Send async analytics request.
let promise = fetch("https://example.com")
.then(response => {
console.log("analytics sent!")
})
// If I uncomment this, only then do I see the
// "analytics sent!" log message. But I don't
// want to wait for it!
// await promise;
return response
}

You need to use Event.waitUntil() to extend the duration of the request. By default, all asynchronous tasks are canceled as soon as the final response is sent, but you can use waitUntil() to extend the request processing lifetime to accommodate asynchronous tasks. The input to waitUntil() must be a Promise which resolves when the task is done.
So, instead of:
await promise
do:
event.waitUntil(promise)
Here's the full working script in the Playground.