Chrome extension: Block page items before access

Question

I am trying to do block items on a webpage but I want to do that, before they are loaded. So, e.g., I could use

chrome.webRequest.onBeforeRequest.addListener(

Answer 1

I was able to achieve what i was trying to do. The solution does not necessarily need extensions anymore, but to setup a proxy this might be useful. Afterwards, the solution (for the specified problem above) is as follows:

• Use a chrome extension to use a proxy, in this case, localhost
• Setup a proxyscript, e.g. using python, to route all traffic (and maybe install certificates, so HTTPs traffic may be analyzed as well)
• => Man-in-the-middle established, analyze traffic and modify if needed

Yes, this is not really a solution to the problem of making a chrome extension do this somehow, but it is not possible yet (see https://bugs.chromium.org/p/chromium/issues/detail?id=104058).

Best regards, mutilis