How to intercept or modify native AJAX requests

jquery has implemented a variety of Ajax events, such as Beforesend, but the native XMLHttpRequest does not have such events. In the absence of jquery, if you want to modify the AJAX request, you have to do some special processing. Here's how I deal with it:

xmlhttprequest.prototype._open = xmlhttprequest.prototype.open; Xmlhttprequest.prototype.open = function (Method, url, async)  {     //  objects for easy modification of parameters     var options = {         method: method,        url: url,         async: async    }    if (' function '  === typeof window.beforexmlhttprequestsend)  {         if (!window.beforexmlhttprequestsend (this, options))  {             return;        }     }    this._open (Options.method, options.url, options.async);}; Window.beforexmlhttprequestsend = function (Xhr, optiONS)  {    //reset Parameters     options.url ==  ' Reset url ';     options.method =  ' PUT ';    options.async =  false;        //Prohibit send request     //return false;         //Send Request     return true;     };

How to intercept or modify native AJAX requests