Add column picker option for number of holds in item context

[Blake GH]

Our libraries have expressed and interest for a feature that would allow them to quickly know about holds on items while viewing a list of items. For example, the items out screen, they would like to be able to inform the patron at the desk about which item(s) have holds and therefore cannot be renewed. The patron would presumably, read those items first and return them first knowing that they would not be able to renew them.

It seems like this information could easily be added to the fleshing of an item. An extra query such as:

select count(*) from action.hold_request where cancel_time is null and fulfillment_time is null and capture_time is null and id in
(select hold from action.hold_copy_map where target_copy=**this copy**)

should return the number of holds on a given item and could be displayed along with all of the other columns in the staff client/web based staff client.

This removes the complex query for checking hold types and comparing them to each of the different targets. Instead, let's use the logic that the hold target has already used and query the hold_copy_map.

[Blake GH (bmagic)]

Here is the code for that

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/blake/LP1402770_column_picker_option_for_number_of_holds

[Andrea Neiman (aneiman)]

I have tested this code and consent to signing off on it with my name Andrea Neiman and email address <email address hidden>

[Kathy Lussier (klussier)]

Just adding a note that I tested this code with production data, and saw no noticeable performance issues when displaying the holds count for an item that had 600+ holds. I'm also noting that, due to the way the count is generated, you can have different counts for different copies on the same record. I don't think it's a problem, but I'm just making note of it because some users may expect the holds count to match the count they see in the bib record.

The branch will need a release notes entry.

[Kathy Lussier (klussier)]

Thanks Blake! I added Andrea's and my signoff to your commit. I also added a release notes entry and added another commit to make the new column picker option hidden in most item interfaces. It was displaying by default in the Check Out tab, In-House Use screen and other interfaces where the info might not be very useful to users. WIth this commit, it continues to display by default in the xul Items Out tab.

[Ben Shum (bshum)]

Pushed to master, thanks Blake, Andrea and Kathy!

[Blake GH (bmagic)]

Good call on the hidden default. That thought crossed my mind as well. Thanks for all of the testing!

[Blake GH (bmagic)]

Oh - and the code also puts that column option in the web based staff client (I don't think anyone mentioned that)

[Kathy Lussier (klussier)]

Hi Blake,

Yes, I saw it in the Items Out tab for the web client. Very nice! i Tried to tweak the code to get it to appear in Item Status in the web client, but gave up when my first few tries didn't work. Thanks for the contribution!