"Is being viewed by now.." question

[ruddie]

Hello, I was wondering how to create the 'This post is being viewed by user1, user2, user3 and ... guests' on a certain location of the forum/website.

 

I was thinking about having all these usernames / guests stored in the mysql database, however this caused an issue for me, since I got no idea if you can/are allowed to place an array in a table.

 

I am hoping someone out here knows what is the easiest/most efficient way of doing this.

 

Thanks in advance.

[PaulRyan]

For this I would do the following...

- Add a new field on the users DB called current_location

- When a person loads a page, update the current_location with the page name

- Then you can select from the database all of the people currently viewing the page and display the count

 

This is probably the easiest method, but someone else may have something better.

 

Regards, PaulRyan

[ruddie]

For this I would do the following...

- Add a new field on the users DB called current_location

- When a person loads a page, update the current_location with the page name

- Then you can select from the database all of the people currently viewing the page and display the count

 

This is probably the easiest method, but someone else may have something better.

 

Regards, PaulRyan

 

I was in fact thinking of that, but I was stuck on the point where people would just exit the browser, what would happen then? Is there a function that somehow gets called when they do this? (I.e. Server loses connection ..)

[MikeDean89]

Paul is correct and you should look to use his method. I'd only change it if you wanted a 'history' type feature, where you can show the last 5 - for example - places the user has visited.

 

The only thing I would add is a 'last_seen' field. This should store the last time the user visited any page on the website and should be updated when the current_location field is. This is so you're not stuck with a potentially huge list containing users who navigated away from your website when visiting a certain page.

 

So to recap:

- Use Paul's method unless you're looking for a "history" feature.

- Add a last_seen field to the DB.

- Update the field when current_location is updated.

- Decide the 'timeout' time so you're not left with users who aren't online any more.

 

Hope this helps.

 

Michael.

[PaulRyan]

Damn MikeDean, knew I forgot something

 

You'd have to update the last_seen field with a Unix Timestamp for simpleness.

Then only select people from the DB who have been online in the last 10 minutes or so?

 

Something like...

<?PHP
  $lastSeen = time()-600; // Upto and including 10 minutes ago
  $myQuery = "SELECT username FROM users WHERE current_location='$thisPage' AND last_seen>$lastSeen AND username!='$loggedUser' ORDER BY last_seen";

  if($doQuery = mysql_query($myQuery)) {
    if(mysql_num_rows($doQuery)) {

      $pageViewers = $loggedUser;

      while($user = mysql_fetch_assoc($doQuery)) {
        $pageViewers .= ', '.$user['username'];
      }

      echo $pageViewers;

    } else {
      echo $loggedUser;
    }
  } else {
    echo 'This query failed: '.$myQuery
  }
?>

 

$loggedUser - The user that is currently logged in, if not logged in set this variable blank.

 

Something like the above would work

 

Regards, PaulRyan.

[ruddie]

Amazing, never thought of that! I can even use this to tell whether the user is online or not! I'll mark the threat solved - Both of you Thanks!

 

Edit: Where did the mark solved button go?

[ruddie]

In fact.. I have been thinking a bit again - And I got no idea how to measure 'Guests'. I guess these will work the same way, but I was thinking about somehow using these people there IP? Perhaps I'll make a 'guest' table for these. I would like to hear your insights on this.

[MikeDean89]

Ah, I think if you're looking to monitor guests too then I'd move this entirely into a new table (so even for users).

 

You can still keep the general idea of what Paul and I (well, mostly Paul) have been discussing. Here's a few things I'd do for this type of feature.

 

- Create an online table with the following fields

-- id

-- session_id.

-- user_id (default this to 0 which will represent a guest, otherwise, it'll store the logged in users ID).

-- IP

-- current_location

-- last_seen

 

- Still update both current_location and last_seen but also look to run a query that deletes any users that are now logged off, i.e. been offline for more than 10 minutes.

$lastSeen = time()-600; // Upto and including 10 minutes ago
$myQuery = "DELETE FROM online WHERE last_seen<$lastSeen";

 

I haven't got a lot of time to go into more detail but that should give you a general idea of how this could work.

 

Of course, there could be a better, more efficient way of doing this.

[ruddie]

Just perfect, and exactly the same way I thought of. Thanks again.