When using :checked with collection_check_boxes, existing associations should be ignored

[watson]

Consider a User who can have many Roles:

class User < ActiveRecord::Base
  has_many :user_roles
  has_many :roles, :through => :user_roles
end

class UserRole < ActiveRecord::Base
  belongs_to :user
  belongs_to :role
end

class Role < ActiveRecord::Base
  has_many :user_roles
  has_many :users, :through => :user_roles
end

One can make a view where a user can be edited and roles can be selected:

= simple_form_for @user do |f|
  = f.name
  = f.email
  = f.association :roles, :as => :check_boxes

By default, when requesting the edit form above, simple_form will list all possible roles that a user can have, checking the onces where a UserRole record exists for the @user object.

But if I add the :checked => [...] option to the f.association call with an array of role id's, I would expect simple_form to pre-check those roles and those roles only. What I get instead, is a set of check boxes with both the existing roles checked + the roles given in the :checked array (i.e. it has merged the @user.user_roles array with the :checked array).

I see the same issue when using f.collection_check_boxes :role_ids, Role.all, :id, :name, :checked => [...] instead of f.association ....

I would expect the array given to :checked to override any existing associations on the @user object. Otherwise simple_form will re-check un-checked check boxes on form validation errors.

[rafaelfranca]

I tried to reproduce this issue and I saw that this is the default behavior of check_box rails helper. I have not figured out how to fix this issue. Any clues @carlosantoniodasilva?

[carlosantoniodasilva]

Hey guys, sorry to delay that much to answer you here.

It really seems to be more a Rails issue than a SimpleForm one, we will try to check what Rails and SimpleForm are doing to see if we can find out what's going on here. Thanks.

[rafaelfranca]

Closed by #374