Example fetch with authorization header: fetch(‘URL_GOES_HERE’, { method: ‘post’, headers: new Headers({ ‘Authorization’: ‘Basic ‘+btoa(‘username:password’), ‘Content-Type’: ‘application/x-www-form-urlencoded’ }), body: ‘A=1&B=2’ });
The problem here is that iOS does not allow HTTP requests by default, only HTTPS. If you want to enable HTTP requests add this to your info.plist: <key>NSAppTransportSecurity</key> <dict> <key>NSAllowsArbitraryLoads</key> <true/> </dict>
Using a promise race solution will leave the request hanging and still consume bandwidth in the background and lower the max allowed concurrent request being made while it’s still in process. Instead use the AbortController to actually abort the request, Here is an example const controller = new AbortController() // 5 second timeout: const timeoutId … Read more
Why does response.json return a promise? Because you receive the response as soon as all headers have arrived. Calling .json() gets you another promise for the body of the http response that is yet to be loaded. See also Why is the response object from JavaScript fetch API a promise?. Why do I get the … Read more
Consider the case in which a service worker acts as an agnostic cache. Your only goal is serve the same resources that you would get from the network, but faster. Of course you can’t ensure all the resources will be part of your origin (consider libraries served from CDNs, for instance). As the service worker … Read more
A solution without dependencies. Node headers.set(‘Authorization’, ‘Basic ‘ + Buffer.from(username + “:” + password).toString(‘base64’)); Browser headers.set(‘Authorization’, ‘Basic ‘ + btoa(username + “:” + password));
There are a few things that you can do with fetch and not with XHR: You can use the Cache API with the request and response objects; You can perform no-cors requests, getting a response from a server that doesn’t implement CORS. You can’t access the response body directly from JavaScript, but you can use … Read more
You have to put together the x-www-form-urlencoded payload yourself, like this: var details = { ‘userName’: ‘test@gmail.com’, ‘password’: ‘Password!’, ‘grant_type’: ‘password’ }; var formBody = []; for (var property in details) { var encodedKey = encodeURIComponent(property); var encodedValue = encodeURIComponent(details[property]); formBody.push(encodedKey + “=” + encodedValue); } formBody = formBody.join(“&”); fetch(‘https://example.com/login’, { method: ‘POST’, headers: { … Read more
To quote MDN on FormData (emphasis mine): The FormData interface provides a way to easily construct a set of key/value pairs representing form fields and their values, which can then be easily sent using the XMLHttpRequest.send() method. It uses the same format a form would use if the encoding type were set to “multipart/form-data”. So … Read more
TL/DR: fetch now supports a signal parameter as of 20 September 2017, but not all browsers seem support this at the moment. 2020 UPDATE: Most major browsers (Edge, Firefox, Chrome, Safari, Opera, and a few others) support the feature, which has become part of the DOM living standard. (as of 5 March 2020) This is … Read more