The old address book had a 'Total contacts in <address book>' counter in the status bar of the Address Book window. Such a counter is useful for a number of reasons.
The new address book implementation is lacking such a counter.
Please add a counter for the no. of contacts in an address book for the new address book implementation.

Yes, and another counter for selected contacts, please!

Is this a lost cause for v102.0?

Unfortunately, the status bar currently is devoted to the main message pane.

I'm seeing questions in Support Forum about where is the total number of contacts they have for mailing lists and address books.

This used to be displayed in the Status Bar.
But if not possible under new design - as an alternative - could it be added to the right of the actual address book/mailing list name - similar to how the Folder Pane has the folder pane columns option to display number of emails in folder ?

Alex can you assign priority etc?
I also miss this fwiw

We weren't able to add new strings for this in 102 as we missed that window.
We still have the old string here: https://searchfox.org/comm-central/rev/ded3b63d927ab68e9ae12d11eddb9929e7527d38/mail/locales/en-US/chrome/messenger/addressbook/addressBook.properties#99

We can temporarily use this old string to show an indicator at the bottom of the Address Book list (first column) only for 102, and then move things forward for post-102 with new strings.

Nicolai, would be able to take care of this?
Also CC'ing Geoff to make him aware of this temporary fix.

The counter for selected contacts was never part of 91, that's an extra feature that we have ready but didn't land because of string freeze.
RFE and regressions shouldn't be listed together in the same bug.

Pushed by mkmelin@iki.fi:
https://hg.mozilla.org/comm-central/rev/2c97012ce4e1
Add total count for a selected address book. r=aleca

Reopen this ticket, the count is not updated on contact creation or deletion.

Pushed by mkmelin@iki.fi:
https://hg.mozilla.org/comm-central/rev/7b2fdfe9e1f4
Update total number of contacts when creating or deleting contacts. r=aleca

(In reply to Alessandro Castellani [:aleca] from comment #6)

We can temporarily use this old string to show an indicator at the bottom of the Address Book list (first column) only for 102, and then move things forward for post-102 with new strings.

Nicolai, can you request uplift for this?

Comment on attachment 9288265 [details]
Bug 1745571 - Add total count for a selected address book. r=aleca

[Approval Request Comment]
Regression caused by (bug #):
User impact if declined: Missing total contacts counter
Testing completed (on c-c, etc.): on c-c, beta
Risk to taking this patch (and alternatives if risky): None

Comment on attachment 9288265 [details]
Bug 1745571 - Add total count for a selected address book. r=aleca

[Triage Comment]
Approved for esr102

Thunderbird 102.3.1:
https://hg.mozilla.org/releases/comm-esr102/rev/b28a4b2184b9
https://hg.mozilla.org/releases/comm-esr102/rev/0bfd400d85bf