Blog / October 4, 2019

What is xmlxmlhttprequest in JavaScript?

XMLHttpRequest is a built-in browser object that allows to make HTTP requests in JavaScript. Despite of having the word “XML” in its name, it can operate on any data, not only in XML format. We can upload/download files, track progress and much more. Right now, there’s another, more modern method fetch, that somewhat deprecates XMLHttpRequest.

Does IE9 support XMLHttpRequest?

That should actually not be the case as IE 9 supports the XMLHttpRequest Object. Believe it or not, ie9 DOES NOT actually support XMLHttpRequest (you can change some settings in your internet options as the end-user, but I’m sure that’s not gonna be an acceptable answer to your boss).

What happens if XMLHttpRequest takes too long?

If a synchronous call takes too much time, the browser may suggest to close the “hanging” webpage. Many advanced capabilities of XMLHttpRequest, like requesting from another domain or specifying a timeout, are unavailable for synchronous requests. Also, as you can see, no progress indication.

Why can’t I scroll the page in XMLHttpRequest?

In some browsers it becomes impossible to scroll. If a synchronous call takes too much time, the browser may suggest to close the “hanging” webpage. Many advanced capabilities of XMLHttpRequest, like requesting from another domain or specifying a timeout, are unavailable for synchronous requests.

Is it possible to open a PDF in the browser via XMLHttpRequest?

I want to do XMLHttpRequest and then open a PDF in the Browser by sending the filename by POST method. Is that possible or XMLHttpRequest is just for HTML? It is not possible to do via XMLHttpRequest if the URL you are querying actually returns the PDF data.

How do I read JSON data with XMLHttpRequest?

Despite its name, XMLHttpRequest can operate on any data, not only XML. The following example creates a request to a testing site and returns the current datetime. This example reads JSON data with XMLHttpRequest . A new instance of XMLHttpRequest is created. The open () method initializes a GET request to the specified URL.

Does XMLHttpRequest support cross-site requests?

Modern browsers support cross-site requests by implementing the Cross-Origin Resource Sharing (CORS) standard. As long as the server is configured to allow requests from your web application’s origin, XMLHttpRequest will work.