Modify Request Body

Question

I'm trying to modify the request body of a request to show the research tool in Google docs. I'm able to trigger on each request that matches, and pull the form_data request body, but I don't see any way of modifying the request body and passing it on. All I need to do is change docs-show_reference to false.

Blocking the request doesn't work, as the page then initiates the request again, leading to a loop. I can't seem to modify the request headers properly to block the request, as the only thing that needs to change is within the form_data request body. It also doesn't appear that it's at all possible to return modified request body through chrome.webRequest

The extension also blocks all non-docs addresses (which is also working).

Here's the code I'm using (that initiates the redirect loop). All the permissions and config in manifest.json is also working properly.

chrome.webRequest.onBeforeRequest.addListener(
  function(info) {
      var request = info.requestBody;
      if (info.url.indexOf(chrome.runtime.id) > -1) {
          console.log("popup: %s",info.url);
          return;
      }
      if (info.url.indexOf("docs.google.com") > -1){
          if (request && request.formData && request.formData.preferences && request.formData.preferences[0] == '{"docs-show_reference":true}') {

             return {cancel:true};
          } else {
            return {cancel:false};
          }
      }
      if (info.url.indexOf('gstatic') > -1) {
          return {cancel:false};
      }

      console.log("blocked: %s",info.url);
      return {redirectUrl:chrome.extension.getURL("blocked.png")};
  },
  // filters
  {
    urls: [
      "<all_urls>"
    ]
  },
  // extraInfoSpec
  ["blocking", "requestBody"]
);

Answer 1

According to Issue 91191, we can't modify form data in chrome extension now.