Detecting a browser addon using JavaScript or C#?

Question

We are writing a website in C#, and we need to detect if the client's browser has a certain (custom developed) add-on installed.

We have figured out a way how to do it when the client is using Firefox or Internet Explorer. How can we do the same with Safari and Chrome?

Have you figured-out Chrome or not? You mention it twice in your question. — WEFX, May 17 '11 at 14:52
I don't agree with those Close votes. This is a real question. — Jeff Yates, May 17 '11 at 15:12
no i haven't figured out the chrome .. i have added to say .. "firefox and IE". — Yousuf Jawwad, May 17 '11 at 15:38
add code to display how the plugin detection was achieved for IE and firefox — Yousuf Jawwad, May 17 '11 at 18:46
Since your detection is actually done in JavaScript (rather than in C#, which just outputs the JavaScript), I've added the javascript tag and changed the title. Hopefully, that will attract JavaScript experts who can help you. — Heinzi, May 19 '11 at 07:18

score 0 · Answer 1 · answered Jun 20 '13 at 06:44

Since addons have permission to modify DOM
using the add-on you can inject some javascript variable(e.g. var IsMyAddonNameInstalled = 'true') into the DOM when your website is requested from browser
and then pass it to server using AJAX request or hidden input field.

PS: This will work on all browsers

score 0 · Answer 2 · answered May 17 '11 at 14:52

0

You can add your Addon name to User-Agent variable of your browser (by modyfing this value in browser settings store, open about:config in URL for Firefox). Then you can read it back from Request object.

answered May 17 '11 at 14:52

Dariusz

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If the UserAgent string gets too long, it can become truncated and information is lost. – Jeff Yates May 17 '11 at 14:54
@Jeff Yates. There is no limitation on HTTP side for that. Do you know any? – Dariusz May 17 '11 at 15:00
Or (depending on the capabilities of the plugin) add it as a custom (X-*) header. – Benjamin Podszun May 17 '11 at 15:00
Maybe not, but it happens on Windows. I had that issue several times and it caused some weird issues as [ASP.NET truncates the User Agent string to 256 characters](http://blogs.msdn.com/b/psssql/archive/2008/12/29/failure-to-load-report-manager-due-to-truncated-useragent-string.aspx). I wouldn't rely on it. – Jeff Yates May 17 '11 at 15:09

Detecting a browser addon using JavaScript or C#?

2 Answers2