CODEWITHSUNDEEP
node.jsexpress
Craig
Craig

Reputation: 36826

Checking other users are viewing this page in Node Express

I have a NodeJs Express app and when a particular user goes to a page/route would like to identify and display if another user is currently viewing the page as well. So for example it would say "Jerry currently viewing this page" and someone else goes there.

Is there any easy/lightweight way to do this?

Upvotes: 0

Views: 505

Answers (1)

jfriend00
jfriend00

Reputation: 708146

First off, with a regular web page, the server only knows who and when a page was requested. It doesn't, all by itself, know whether that user is still viewing that page or not. The user could have closed the browser, typed something else in the URL bar, the computer could have gone to sleep, etc...

Second off, even if the page is still being displayed in the browser, you can't know if someone is actually there at the computer or not. The best you could do is to try to keep track of activity in that web page (last mouse click, recent mouse movements over the web page, etc...).

Then, to even have any idea of the web page is even still open in the browser, you need some way of tracking that notion. There are two possibilities I can think of.

  1. You can have some Javascript in the web page that regularly (say once every few minutes) sends a small little ajax call to your server that basically just says "I'm still here". This wouldn't know immediately when they left the page, but if the server finds that the usual every few minutes ajax call didn't come, then the server can change the status of that user on that page to not there any more.

  2. If that web page makes a webSocket or socket.io connection to the server and keeps that connection alive, then whenever the browser closes or the user closed that tab or navigates to another page, that webSocket or socket.io connection will get automatically closed and the server will be notified that the socket got closed. Using this technique, the server can know pretty much right away when the user leaves the page.

Upvotes: 2

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