Which JavaScript library or framework offers support for the "onprogress" event for XmlHttpRequest, even if it needs to be emulated using a plugin or extension? Alternatively, which JavaScript framework is the most straightforward to extend in order to add support for xhr.onprogress?
When I mention "emulated if necessary" here, I am referring to the scenario where the web browser does not support the XHR 2.0 "onprogress" event. In such cases, the "onreadystatechange" event would be utilized instead. However, some browsers only fire onreadystatechange once per state change and do not call onreadystatechange during server flushes. Thus, a timer or interval may need to be implemented to periodically check the XHR object in these situations.