On Aug 14, 7:58 pm, Michael Baldock <[email protected]> wrote:
> I've got a table of events, and each event has a boolean attribute
> is_ten_event.
>
> On each row of the table is a chekbox to edit the value of is_ten_event,
> so that multiple rows can be edited with one submit.
>
> In order to allow boxes to be un-checked as well, the logic in the
> controller works like this
>
> get array of events from checkboxes that are ticked.
> make all events.is_ten_event = false
> make all events in array . is_ten_event = true
>
> When I first check the checkbox and submit, everything works fine, the
> attribute is updated in the database and the table view reflects the
> changes.
> If I then submit again, with the same values still checked the values I
> set the last time get set to false.
The problem is rails' change tracking. When you save a record, active
record checks whether there are actually any changed attributes and
saves those. You've loaded your events from the database, which have
your flag set to true. Then you call update_all which changes
everything to false in the database, but doesn't update any objects
that already exist in memory, so when you call update attribute, rails
thinks you are setting to true something that is already true and
doesn't do anything.
Fred
>
> The view code looks like this :
>
> check_box_tag "is_ten_event_ids[]", event.id, event.is_ten_event
>
> The controller is like this :
>
> def multi_params_edit
>
> @events = Event.find( params[:is_ten_event_ids] )
> logger.debug("MULTI PARAMS EDIT : " + @events.length.to_s)
>
> unless @events.empty?
>
> Event.transaction do
> Event.update_all(:is_ten_event => false)
> @events.each do |e|
> logger.debug("trying to make event is_ten_event = true")
> e.update_attribute(:is_ten_event, true)
> end
> end
> end
>
> redirect_to (:action =>:index)
>
> end
>
> Here's the log output from the first submit (when it works)
>
> Started POST "/admin/events/events/multi_params_edit" for 127.0.0.1 at
> Sun Aug 14 19:37:42 +0100 2011
> Processing by Admin::Events::EventsController#multi_params_edit as
> HTML
> Parameters: {"commit"=>"save changes (not functional)",
> "authenticity_token"=>"3MJ8aUhRWkrsOTLzkcLup8s7wrQH387H7uJeeKEU9Ss=",
> "utf8"=>"✓", "is_ten_event_ids"=>["5", "12", "20"]}
> User Load (0.2ms) SELECT "users".* FROM "users" WHERE ("users"."id" =
> 3) LIMIT 1
> AREL (0.4ms) UPDATE "users" SET "last_access" = '2011-08-14
> 18:37:42.858005', "updated_at" = '2011-08-14 18:37:42.858858' WHERE
> ("users"."id" = 3)
> Event Load (0.6ms) SELECT "events".* FROM "events" WHERE
> ("events"."id" IN (5, 12, 20))
> MULTI PARAMS EDIT : 3
> AREL (1.9ms) UPDATE "events" SET "is_ten_event" = 'f'
> trying to make event is_ten_event = true
> AREL (0.2ms) UPDATE "events" SET "is_ten_event" = 't', "updated_at" =
> '2011-08-14 18:37:42.913564' WHERE ("events"."id" = 5)
> trying to make event is_ten_event = true
> AREL (0.1ms) UPDATE "events" SET "is_ten_event" = 't', "updated_at" =
> '2011-08-14 18:37:42.916311' WHERE ("events"."id" = 12)
> trying to make event is_ten_event = true
> AREL (0.1ms) UPDATE "events" SET "is_ten_event" = 't', "updated_at" =
> '2011-08-14 18:37:42.918503' WHERE ("events"."id" = 20)
> Redirected tohttp://0.0.0.0:3000/admin/events/events
>
> And here's the log output from the second submit (when it doesn't work)
>
> Started POST "/admin/events/events/multi_params_edit" for 127.0.0.1 at
> Sun Aug 14 19:37:49 +0100 2011
> Processing by Admin::Events::EventsController#multi_params_edit as
> HTML
> Parameters: {"commit"=>"save changes (not functional)",
> "authenticity_token"=>"3MJ8aUhRWkrsOTLzkcLup8s7wrQH387H7uJeeKEU9Ss=",
> "utf8"=>"✓", "is_ten_event_ids"=>["5", "12", "20"]}
> User Load (0.3ms) SELECT "users".* FROM "users" WHERE ("users"."id" =
> 3) LIMIT 1
> AREL (0.4ms) UPDATE "users" SET "updated_at" = '2011-08-14
> 18:37:50.369619', "last_access" = '2011-08-14 18:37:50.368912' WHERE
> ("users"."id" = 3)
> Event Load (0.6ms) SELECT "events".* FROM "events" WHERE
> ("events"."id" IN (5, 12, 20))
> MULTI PARAMS EDIT : 3
> AREL (1.9ms) UPDATE "events" SET "is_ten_event" = 'f'
> trying to make event is_ten_event = true
> trying to make event is_ten_event = true
> trying to make event is_ten_event = true
> Redirected tohttp://0.0.0.0:3000/admin/events/events
>
> As you can see, in both cases, the 3 event ids which are checked get
> passed through, and the length of the @events array is 3. After all
> events are set to false, the first log staement shows the block being
> executed, and the database being updated. The second log statement shows
> that although the block was run (from the printout "trying to make event
> is_ten_event = true") the update_attribute call didn't do anything!
>
> CAn anyone tell me why?? it seems very simple this, so probably doing
> something silly.
>
> What is also odd however is that I wrapped the whole thing in a
> Transaction, which should ensure that if the update_attribute didn't
> work, the set all events to is_ten_event = false call should be rolled
> back, but this doesn't happen either!
>
> I'm losing faith in transaction as a method, and update_attribute.
> I'm somewhat losing faith in reality!
>
> Can anyone please help!??
>
> --
> Posted viahttp://www.ruby-forum.com/.
--
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Talk" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.
