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Re: Catching http request with JavaScript

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In article <568e31ca$0$19736$426a74cc@news.free.fr>, mireero
<mireero@free.fr> wrote:

>Hi,
>
>Some addons like adblocks, ghostery... are using some browser specific 
>functionalities to "regular expression block" some specific http requests.
>
>Is there any cross-browser way of achieving something similar using 
>regular JavaScript?
>
>For example I'd like to block some <img> tag or to modify on the fly 
>involved request headers.
>
>I know you cannot act on the DOM before it is loaded and after it looks 
>too late but I'm still asking as my knowledge isn't 100% wide.

What I do is create a new DOM element, load the html into that, then
modify *that* DOM to remove <img> or other tags I don't trust, and then
load that modified DOM into an <iframe> for display.

This also prevents the browser from doing speculative downloading of
(e.g.) images while your javascript is still running. What I had done
originally was load the HTML into the live DOM, and then modify it, on
the basis that I could do that before rendering started because
javascript is supposed to be single-threaded. But I still saw network
activity of images being downloaded and then guessed that the browser
was doing stuff behind my back.

-- 
"If you're not able to ask questions and deal with the answers without feeling 
that someone has called your intelligence or competence into question, don't 
ask questions on Usenet where the answers won't be carefully tailored to avoid
tripping your hair-trigger insecurities."                  - D M Procida, UCSM

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Thread

Catching http request with JavaScript mireero <mireero@free.fr> - 2016-01-07 10:36 +0100
  Re: Catching http request with JavaScript Tim Streater <timstreater@greenbee.net> - 2016-01-07 09:44 +0000
  Re: Catching http request with JavaScript Stefan Weiss <krewecherl@gmail.com> - 2016-01-07 13:49 +0100
  Re: Catching http request with JavaScript JJ <jj4public@vfemail.net> - 2016-01-08 13:08 +0700

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