Editing ticket field values from ITicketChangeListener's ticket_changed()

[Daniel Abel]

Hi!

I am working a plugin which would help time-related ticket
activities. The functionality I would like to have is to

1) e-mail notifications / warnings if a ticket spends too much time in
a given state.

2) have automatic transitions, i.e. tickets get transfered from status
A to status B after a given time.

3) show the dates/time involved in the features above on the ticket
view pages, allow searching based on them, etc.


My implementation plan is to create a plugin that implements
ITicketChangeListener, and in ticket_changed() check whether the
ticket entered one of the states which have a time-limit
configured. If yes,
1) store the current time in a custom foo_state_entered_date field
2) set a callback by invoking 'at', which will run a small script

The part where I got stuck is setting a field's value from
ticket_changed(). Following erikand's suggestion (on #trac) I thought
the following would work:

ticket[fieldname] = datetime.date.today().isoformat()
ticket.save_changes('auto-script',None)

which would be simple, and it would store such automatic changes in
the ticket's changelog. However, this throws an exception:


Traceback (most recent call last):
File "$pkg/trac/web/main.py", line 398, in _dispatch_request
dispatcher.dispatch(req)
File "$pkg/trac/web/main.py", line 195, in dispatch
resp = chosen_handler.process_request(req)
File "$pkg/trac/ticket/web_ui.py", line 159, in process_request
return self._process_ticket_request(req)
File "$pkg/trac/ticket/web_ui.py", line 459, in
_process_ticket_request
self._do_save(req, ticket, action)
File "$pkg/trac/ticket/web_ui.py", line 943, in _do_save
cnum=internal_cnum):
File "$pkg/trac/ticket/model.py", line 276, in save_changes
listener.ticket_changed(self, comment, author, old_values)
File "/home/abeld/WORK/trac-for-internal-inventory/trac-install/
plugins/proba.py", line 54, in ticket_changed
ticket.save_changes('auto-script',None)
File "$pkg/trac/ticket/model.py", line 264, in save_changes
(self.id, when_ts, author, cnum, comment))
File "$pkg/trac/db/util.py", line 50, in execute
return self.cursor.execute(sql_escape_percent(sql), args)
File "$pkg/trac/db/sqlite_backend.py", line 58, in execute
args or [])
File "$pkg/trac/db/sqlite_backend.py", line 50, in
_rollback_on_error
return function(self, *args, **kwargs)
IntegrityError: columns ticket, time, field are not unique


(where $pkg in the filenames is
/home/abeld/temp-trac-install-dir/lib/python2.4/site-packages/
Trac-0.11b1-py2.4.egg
as I am using a locally-installed 0.11b1; and the trac instance is at
/home/abeld/WORK/trac-for-internal-inventory/trac-install/)



So, how should I be doing this? (I would like to store the date
explicitly, even though it could be figured out by parsing the
ticket's changelog, as well. However, having it stored in a seperate
field means it is possible to show in the ticket view page / search
for, and that manual editing of it can be allowed.)

Should the above, or some variation of it work? Or do I have to open a
new connection to the database? If the latter, are there any issues
with multiple simultaneous connections to the db? (I am using sqlite
db backend)

Thanks in advance,
Daniel Abel
ab...@freemail.hu

[Erik Andersson]

Hi

Unfortunately I only had an example for ticket_created, and I do not know how things are supposed to be handled in ticket_changed, but hopefully someone else will now let us know..

Regarding sqlite: sqlite does only handle one transaction at a time, so if you need multiple simultaneous connections to the db you will be better of with postgres. Performancewise I've been told that sqlite and postgres are about the same, but with postgres you get better throughput since you don't need to wait for locks..

Cheers / Erik