Rolling back transactions

[edoloughlin]

Hi all,

I'm trying to use clj-record.core/transaction to rollback based on
some logic.

I don't want to throw exceptions directly, as I'm using ring and it
works nicely with clojure.contrib.condition/raise. However, a clj-
record transaction seems to ignore this and my transacitons don't get
rolled back. If I use (clojure.contrib.sql/set-rollback-only) then my
transaction does get rolled back but I get an ugly exception thrown:

java.lang.Exception: transaction rolled back: null
at clojure.contrib.sql.internal$throw_rollback.invoke(internal.clj:
142)
at clojure.contrib.sql.internal$transaction_STAR_.invoke(internal.clj:
169)
[... my code]

Any advice as to how I might cleanly roll back without mixing Java
exceptions and clojure.contrib.condition's?

Thanks,
Ed O'Loughlin

[Shantanu Kumar]

Do either of these help?

http://bitumenframework.blogspot.com/2010/11/non-breaking-error-handling-in-clojure.html

http://clojuredocs.org/clojure_contrib/clojure.contrib.condition/handler-case

Regards,
Shantanu

[John D. Hume]

I don't have any suggestions off-hand, but do let the list know if you see a change that could be made to clj-record that would make this cleaner.

-- typed with my thumbs

[edoloughlin]

I implemented something similar to contrib.sql/transaction and
contrib.sql/set-rollback to cause a condition to be raised. The code's
at https://gist.github.com/760295

Call rollback-with-raise within a transaction body to cause a
condition to be raised with a specific error code. I haven't included
my.util.error/raise-with-message as it does some error text lookup
specific to my app but it's simple to implement.

On Dec 1, 4:07 pm, "John D. Hume" <duelin.mark...@gmail.com> wrote:
> I don't have any suggestions off-hand, but do let the list know if you see a
> change that could be made to clj-record that would make this cleaner.
>
> -- typed with my thumbs