cc2.0: Problems with multiple rules for same controller

[gamov]

Some of my findings using cc2.0: 1 . Craps out with multiple rules going through the same nested association:

Sale.joins(:order_request => :business_site).where({:order_request => {:business_site => {:business_id => 12}}} | {:order_request => {:business_site => {:name => '3'}}} )

works fine in the console (Sale belong_to OrderRequest belong_to BusinessSite belong_to Business) When I write the follow rule: can :access, :sales, {:order_request => {:business_site => {:business_id => 3}}} Sales index display fine but if I duplicate the rule (or add any other rules referencing :business_site, I get the following malformed SQL:

SELECT "sales".* FROM "sales" INNER JOIN "order_requests" ON "order_requests"."id" = "sales"."order_request_id" INNER JOIN "business_sites" ON "business_sites"."id" = "order_requests"."business_site_id" WHERE (("order_requests"."business_sites" = '---
:business_id: 3
') OR ("order_requests"."business_sites" = '---
:business_id: 3
'))

The debugger tells me that it's the '@model_class.send(:sanitize_sql, conditions)' line in ActiveRecordAdapter that returns the malformed SQL. Indeed:

Sale.send(:sanitize_sql, order_request: {business_site: {business_id: 4}})
# => "\"order_request\".\"business_site\" = '---\n:business_id: 4\n'"

Update: This is actually a misuse of sanitize_sql, it should be at most 1 level deep. In that case, order_request should be removed.

2 . cc shouldn't duplicate same rules As we see, cc OR'ed the two rules conditions (as stated in the doc). However, when the rule is the same, it shouldn't, should it?

3 . Multiple overlapping roles I found out of those issues when I was adding different roles to a user. Those roles abilities overlap for some controllers. This means I can't be sure that all role configurations will work together... I'm wondering what should I do to have a predictable behavior.

Ruby: 1.9.3 / Rails 3.0.20

[mikepack]

CanCan can't handle complex SQL very well, due to the nature of constructing queries. Specifically, joining through numerous tables. I'm not sure if @ryanb has plans to dig deep into this issue but this might help in the meantime:

The longer your can declaration, the deeper the query. Though it's unideal, try denormalizing your dataset a bit. This might be too long:

can :access, :sales, {:order_request => {:business_site => {:business_id => 3}}}

If you denormalized your data so that business_id lived on your sale model, your authorization declaration could be simplified:

can :access, :sales, {:business_id => 3}

[graywh]

You can use through associations instead of denormalizing

class Sales < ActiveModel::Base
  belongs_to :order_request
  has_one :business_site, :through => :order_request
  has_one :business, :through => :business_site
end

so the ability is similar

can :access, :sales, :business_site => { :business_id => 3 }

Alternatively, you could also do

can :access, :sales, :business => { :id => 3 }

[gamov]

Thanks for your comments @mikepack and @graywh. At this point of time, I don't want to denormalize. I've just tried using :through associations but cc fails the same. In the meantime, I'll add unless/if clauses in my ability files where needed... :o(

[graywh]

Sorry, I tried entering that without looking at how I'd done it before. I've updated my comment.

[mikepack]

@graywh belongs_to does not have a :through option. I believe you're looking for has_one. This is a good thought, but it doesn't ultimately eliminate the join which is the cause of the issue. Denormalizing would be the only way to eliminate the join.

[graywh]

It does use joins, but it works for me with 1.6.8. Did something change in 2.0 to break that?

And thanks for the correction.

[graywh]

To clarify, with Cancan 1.6.8 (or branch 2.0) and ActiveRecord 3.2.8, all the through associations, and these abilities

can :manage, Sale, :business => { :id => 3 }
can :manage, Sale, :business => { :name => '3' }

it generates the following SQL with Sale.accessible_by

SELECT "sales".* FROM "sales"
INNER JOIN "order_requests" ON "order_requests"."id" = "sales"."order_request_id"
INNER JOIN "business_sites" ON "business_sites"."id" = "order_requests"."business_site_id"
INNER JOIN "businesses" ON "businesses"."id" = "business_sites"."business_id"
WHERE (("businesses"."id" = 3) OR ("businesses"."id" = 3))

[gamov]

@graywh have you tried setting both ability declarations to :business => { :id => 3}

[xhoy]

Thanks for your submission! The ryanb/cancan repository has been inactive since Sep 06, 2013. Since only Ryan himself has commit permissions, the CanCan project is on a standstill.

CanCan has many open issues, including missing support for Rails 4. To keep CanCan alive, an active fork exists at cancancommunity/cancancan. The new gem is cancancan. More info is available at #994.

If your pull request or issue is still applicable, it would be really appreciated if you resubmit it to CanCanCan.

We hope to see you on the other side!