[rt-users] What do "first", "last" and "all" mean in --transaction on rt-crontool?

[Thomas Sibley]

On 07/16/2013 08:48 PM, Craig Ringer wrote:
> They're not related to database-level transactions since RT doesn't make
> use of them.

This is wrong.  RT _does_ make use of DB transactions.  grep for
BeginTransaction and/or Rollback.

> It looks like --transaction picks an *existing* transaction to set as
> the context of the cronjob. 'first' for the tx that created the ticket,
> 'last' for the most recent ticket, or 'all' to select all transactions
> on the ticket.
> 
> [snip lots more]

Yes, that all sounds about right without verifying myself.

> I'm a little puzzled by the way crontool doesn't seem to have the
> ability to create a *new* transaction for matching tickets. I guess the
> action code is supposed to do that if a new transaction is required, eg
> when adding a Comment to a ticket.

rt-crontool can create new transactions by using the normal RT actions,
just as you describe.  I'm not sure why it seems odd to you.

crontool is fundamentally a way to run scrip conditions/actions over a
batch of tickets/transactions on a time-based trigger rather than solely
event-based.

> Some actions and conditions don't require a transaction context, and for
> those no --transaction should be specified; there's an implicit
> "--transaction none" where "undef" is passed as the transaction to act
> on in process(...) .
> 
> This can result in unexpected effects, like sending mail in the name of
> the person who last did something on the ticket, so it's best to avoid
> specifying a transaction unless you know you need one and one makes
> sense in that context.
> 
> For example, if you invoke RT::Action::SendEmail, it'll use the
> transaction in GetFriendlyName to get the creator of the current
> transaction and from it, the friendlyname. Same with SetReturnAddress.

FWIW, the Notify* subclasses are generally much more useful than the
SendEmail action directly.

> It might be worth elaborating on this a little more in the documentation
> and/or book. Feel free to use any of the above.

As is, the above isn't really suitable for pasting into the usage doc
for rt-crontool.  A doc patch based on the above that fits with the rest
of the doc would be appreciated, though.

Thomas