"Show unread posts since last visit" not working

Rick · Sep 15, 2009, 09:09:56

It's almost certainly that the forum is getting a brief glimpse of you and thinking that you've visited it more recently than the last time you actually gave the forum any attention.

RobertM · Sep 15, 2009, 09:57:26

Ditto here too. There is nothing consistently wrong but I'm finding that posts are definitely being missed.

Rick · Sep 15, 2009, 10:42:26

I can think of situations when "Show unread posts since last visit" will miss posts, depending on what sets the "this is when you last visited" time. Consider the following sequence:

*:01 You click on "Show unread posts since last visit" and start reading posts
*:03 Someone else adds a post to a thread that's not showing up in your list
*:05 You finish off reading, maybe by posting something.

My guess is the next time you click on "Show unread posts since last visit" it'll use the *:05 time, and miss the *:03 post...

On a quiet forum when there's seldom more than one person online it'll work fine. If there're a hundred it'll be not much use. I rely on the main indexes...

mickw · Sep 15, 2009, 11:58:02

Perhaps hitting "Refresh" before you quit the current session ?

OK, that's not the answer

I just quit the forum with no new posts visible, then restarted and there were "new posts" showing in the section headings.
I had a nose around the sections and read the new ones but I didn't notice one of them

When I went back to the main menu and hit Refresh, there were no new posts showing under the sections but when I clicked "Show unread......" the one I missed showed up.

Don't know if that helps or confuses things more

Rick · Nov 12, 2009, 00:06:04

It seems there's also something odd that happens if someone edits a post. Not sure exactly what, though...

Mac · Nov 15, 2009, 20:42:48

show unread posts since last visit and also "Click here to try all unread topics."

dosent seem to be working today.
well at least from about 3pm anyway.

Mac.

Carole · Nov 15, 2009, 21:32:06

Mine hasn't worked for a couple of months. I've given up now and just look for the blue tags. It does mean I miss the odd post now and then though.

Carole

Ian · Nov 16, 2009, 10:59:47

it's probably worth avoiding the "back" button too. Lots of the forum is clickable (for example Orpington Astronomical Society > Random Rambling Ruminations > Updates and Upsets > in blue above will take you back to the forum you came from. The browser will then give you a fresh impression of the page with any updates that have appeared in the mean time.

Carole · Dec 11, 2009, 00:04:11

Well after not working for several months it suddenly started working again this evening!!!!

But will it last?

Carole

Carole · Jan 13, 2010, 15:51:42

This is still not working reliably and I keep missing important posts. Is this something to do with my PC settings and if so, what should I do?

Carole

Rick · Jan 13, 2010, 16:29:07

It is known not to be 100% reliable because it uses a very simple mechanism which cannot catch everything.

Quote from: Carolepope on Jan 13, 2010, 15:51:42what should I do?

I would suggest not relying on it, at least for important messages (whichever they may be).

mickw · Jan 14, 2010, 10:21:07

Just curious, are the read/unread flags generated by cookies ?

A lot of people have reported this problem so it's either a forum issue or something our systems are doing. A common thing we do on our PCs is delete cookies or prevent them.

Rick · Jan 14, 2010, 19:06:13

The forum does use cookies, but only (as far as I can tell^*1) for login. It may get confused if you delete cookies while you're reading the forum.

There is a database table keyed on user and board IDs with a field for message number. As far as I can tell it's a "low water" level rather than a post-by-post one^*2, but it might be trying to be a bit cleverer than that so that some holes in your reading history survive for a while.

One thing it might be worth trying is making use of the "Mark All Read" option occasionally, as that'll make sure it has a clear line to start at.

Also, if you have a category hidden (aka "collapsed") then you may well not see any new posts in it^*3.

Obviously, if (for some reason) you're not logged in then the forum won't adjust (or use) your last visit pointers.

^{*1 It's possible it might use cookies to get a "last time I visited" value, but the experiments I've done suggest that it doesn't.}

^{*2 A post-by-post table would, of course, get stupidly large very quickly...}

^{*3 There's a hideous join in the query that determines what's read and what's not read which includes invormation about hidden categories.}

mickw · Jan 14, 2010, 19:55:12

Cheers Rick

Looks like it's not an easy fix after all, shame

Rick · Jan 15, 2010, 00:10:55

I think it tries to keep some sort of track of holes in your reading, so that it can flag as new posts you've not yet read, even though they're older than posts you have read. However, I suspect it doesn't always succeed.

I suspect it does suffer a bit from the window of missed opportunity problem I described earlier.

If you make much use of the

and

buttons then I think you'll probably also increase your chances of missing something.

So, in summary:

We know it's not perfect
Use it, by all means
Don't rely on it to show you everything you might have missed
Help it out by using the MARK READ link when you're done with a board
Cross-check against the "Recent Posts" list at the bottom of the screen

News:

"Show unread posts since last visit" not working