Skip to main content

Fetch fails when exceeding a certain execution time even-though using proper CORS headers

I have been stuck with a weird issue with CORS for quite some time now. To explain the setup I have a frontend JS snippet (including fetch API call to my own server) which I want to use as an embed code snippet other web applications can use. (ex: kind of like google analytics)

// JS snippet to copy to an unknown website 

<script>
// extract data and add to the body
const extracted_data = {}

fetch("https://api.xxxx.com/xxxxxx/create", {
        method: "POST",
        mode: 'cors',
        body: JSON.stringify(extracted_data),
        referrer: "origin",
        headers: {
            'Content-Type': 'application/json',
        },
    })
        .then(function (response) {
            // The API call was successful!
            if (response.ok) {
                return response.json();
            } else {
                return Promise.reject(response);
            }
        })
        .then(function (data) {
            // This is the JSON from our response
            console.warn("Successfull!", data);
            alert("Success:" + JSON.stringify(data));
        })
        .catch(function (err) {
            // There was an error
            console.warn("Something went wrong ->", err);
            alert("error:" + err.message);
        });

</script>

enter image description here

The problem is even if I have set my fetch API as below and the correct CORS headers are in my preflight response from my API it works only when the API call resolves immediately. If the API takes more time Fetch throws this common error even if the preflight is successful.

TypeError: Failed to fetch

I verified it using adding the below code to my API. Then it stops working and throws the above error. When I don't have any time taking functions inside my API call it works without errors.

 // 10 sec delay to check async behavior of the API
 await new Promise(resolve => setTimeout(resolve, 10000));

Any recommendations on how I should proceed to resolve this?

Via Active questions tagged javascript - Stack Overflow https://ift.tt/0FHRokm

Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

How to show number of registered users in Laravel based on usertype?

i'm trying to display data from the database in the admin dashboard i used this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count(); echo $users; ?> and i have successfully get the correct data from the database but what if i want to display a specific data for example in this user table there is "usertype" that specify if the user is normal user or admin i want to user the same code above but to display a specific usertype i tried this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count()->WHERE usertype =admin; echo $users; ?> but it didn't work, what am i doing wrong? source https://stackoverflow.com/questions/68199726/how-to-show-number-of-registered-users-in-laravel-based-on-usertype
Post a Comment
Read more

Why is my reports service not connecting?

I am trying to pull some data from a Postgres database using Node.js and node-postures but I can't figure out why my service isn't connecting. my routes/index.js file: const express = require('express'); const router = express.Router(); const ordersCountController = require('../controllers/ordersCountController'); const ordersController = require('../controllers/ordersController'); const weeklyReportsController = require('../controllers/weeklyReportsController'); router.get('/orders_count', ordersCountController); router.get('/orders', ordersController); router.get('/weekly_reports', weeklyReportsController); module.exports = router; My controllers/weeklyReportsController.js file: const weeklyReportsService = require('../services/weeklyReportsService'); const weeklyReportsController = async (req, res) => { try { const data = await weeklyReportsService; res.json({data}) console...
Post a Comment
Read more

ValueError: X has 10 features, but LinearRegression is expecting 1 features as input

So, I am trying to predict the model but its throwing error like it has 10 features but it expacts only 1. So I am confused can anyone help me with it? more importantly its not working for me when my friend runs it. It works perfectly fine dose anyone know the reason about it? cv = KFold(n_splits = 10) all_loss = [] for i in range(9): # 1st for loop over polynomial orders poly_order = i X_train = make_polynomial(x, poly_order) loss_at_order = [] # initiate a set to collect loss for CV for train_index, test_index in cv.split(X_train): print('TRAIN:', train_index, 'TEST:', test_index) X_train_cv, X_test_cv = X_train[train_index], X_test[test_index] t_train_cv, t_test_cv = t[train_index], t[test_index] reg.fit(X_train_cv, t_train_cv) loss_at_order.append(np.mean((t_test_cv - reg.predict(X_test_cv))**2)) # collect loss at fold all_loss.append(np.mean(loss_at_order)) # collect loss at order plt.plot(np.log(al...
Post a Comment
Read more