How to intercept all http requests including form submits

Question

I would like to intercept all http requests going out from my web page and add a parameter to the request body. My page includes forms - I also want to capture form submits. I have tried using Jquery ajaxSend and Javascript's setRequestHeader but both did not work for me. How do I achieve this?

Thanks

Answer 1

https://developer.mozilla.org/en/docs/Web/API/Service_Worker_API

Service workers essentially act as proxy servers that sit between web applications, and the browser and network (when available).

It takes the form of a JavaScript file that can control the web page/site it is associated with, intercepting and modifying navigation and resource requests

You register a service worker in your application code from a file named, e.g., sw.js by doing:

if ('serviceWorker' in navigator) {   window.addEventListener('load', function() {     navigator.serviceWorker.register('sw.js').then(function(registration) {       console.log('Service worker registered with scope: ', registration.scope);     }, function(err) {       console.log('ServiceWorker registration failed: ', err);     });   }); } 

And in the sw.js file (the actual service-worker code): To intercept requests, you attach a fetch event listener to the service worker that calls the respondWith() method and does something with the .request member from the event object:

self.addEventListener('fetch', function(event) {   event.respondWith(     // intercept requests by handling event.request here   ); }); 

A simple service worker that just passes through requests unchanged looks like this:

self.addEventListener('fetch', function(event) {   event.respondWith(     fetch(event.request)   ); }); 

To add a param to the request body, you need to:

1. Serialize the request.
2. Modify that serialized request.
3. Deserialize the modified request to create a new request.
4. Call fetch(…) with that new request.

So, a service worker that does all that would look like this (untested):

self.addEventListener('fetch', function(event) {   event.respondWith(     fetchWithParamAddedToRequestBody(event.request)   ); }); function fetchWithParamAddedToRequestBody(request) {   serialize(request).then(function(serialized) {     // modify serialized.body here to add your request parameter     deserialize(serialized).then(function(request) {       return fetch(request);     });   }); // fixed this } function serialize(request) {   var headers = {};   for (var entry of request.headers.entries()) {     headers[entry[0]] = entry[1];   }   var serialized = {     url: request.url,     headers: headers,     method: request.method,     mode: request.mode,     credentials: request.credentials,     cache: request.cache,     redirect: request.redirect,     referrer: request.referrer   };     if (request.method !== 'GET' && request.method !== 'HEAD') {     return request.clone().text().then(function(body) {       serialized.body = body;       return Promise.resolve(serialized);     });   }   return Promise.resolve(serialized); } function deserialize(data) {   return Promise.resolve(new Request(data.url, data)); } 

Note: https://serviceworke.rs/request-deferrer_service-worker_doc.html, a page from the Service Worker Cookbook, is where I lifted that serialize(…) code/approach from—by way of the answer at https://stackoverflow.com/questions/35420980/how-to-alter-the-headers-of-a-request/35421644#35421644—and it’s worth taking a look at, because the code there has detailed annotations explaining what it’s all doing

Answer 2

try this code :

(function(send) {  XMLHttpRequest.prototype.send = function(data) {      var _valuToAdd = $("input[name='valuToAdd']").val();     this.setRequestHeader('valueName', _valuToAdd);     send.call(this, data); }; })(XMLHttpRequest.prototype.send);