Access non-privileged js function from privileged code ?

[Lianghwa Jou]

Hi,

A video player on a third party web site provides a function to return
the duration of the video. I am writing a firefox extension and want to
get the duration information. I don't want to invoke non-privileged code
directly to cause security problem. I wonder if the following scheme
will work.

The extension will modify the web page (window.content) and insert
javascript code into its dom. The inserted code will call the player
function and get the duration. It will then post a custom event with
duration as an attribute so the privileged event handler can get the
duration. Will this work ? Any other suggestion ?

thanks,