Thanks for you reply :) I can get the userId,of course, i am using 'linebot' SDK with node.js.
My question is about to set rich menu's uri action dynamically,like append the userId as parameter to the url. For now,my solution is send specific keyword and generate linkbutton for the url dynamically and reply the template message. All i want to know is whether existing a way to directly redirect user to the same page as above(generated by userId dynamically) by clicking the rich menu content button or not?
For the other problem is completely answered, sincerely thanks again for your help.
You can get the user id. Which SDK are you using?
As for your other question, you could do a browser sniff and have your website send a request to your webhook.