Rails - Apr 2006 - Problems with multiple ActiveRecords and Validations

Hi all,

I am a RoR newbie and have the following scenario set up:

There are 2 ActiveRecords involved, the first one being "User", the 
second one being "Visibility".

The corresponding users table holds address informations regarding a 
User. The visibilities table holds visibility settings for the 
individual columns of the users table (i.e. firstname, lastname, country 
should be visible to everybody while the credit card data should be only 
visible to the admin, and so on) for individual users. It has 
practically the same schema as the users table and a foreign key, namely 
user_id. The relationship between the tables is 1:1.

Now I have created an "edit user profile" view which displays all the 
individual form elements corresponding to the columns of the user table. 
Next to each form element is a checkbox which is populated from the 
visibilities-table. (Un-)checking the checkbox you can decide which 
elements should be visible in the "show user profile" view. I hope you
can follow me so far.

Everything is handled from a UserController which extracts the 
visibility alongside the user and prepares everything for display.

Problems arise, if the ActiveRecord validations come into play (e.g. 
there is a validates_presence_of :lastname rule). If everything 
validates successfully, the update action is invoked and all changes are 
saved (in the users and visibilities tables). But if a validation fails 
and the edit user profile view is rendered once again ONLY the submitted 
values of the User ActiveRecord are filled into the form fields once 
again. But all the checkboxes are unchecked!

I haven''t been able to figure out what exactly does happen in case a 
validation fails, although I have screened the source code of the 
ActiveRecord and ActiveView classes and come across the magic errors 
object.


Here some source code:

users_controller.rb:

def edit
  @user = User.find(params[:id])
  @visibility = @user.visibility
end

user.rb
class User < ActiveRecord::Base
  validates_presence_of :lastname, :firstname
  has_one :visibility
end

edit.rhtml (excerpt)
<%= text_field ''user'', ''lastname''  %>
<%= check_box ''visibility'', ''lastname'',
{}, "public", "admin" %> </p>


I am desperately trying to make that work. Any ideas?

Best regards,
 Dominik

-- 
Posted via http://www.ruby-forum.com/.

Dominik wrote:
> users_controller.rb:
> 
> def edit
>   @user = User.find(params[:id])
>   @visibility = @user.visibility
> end
> 
> user.rb
> class User < ActiveRecord::Base
>   validates_presence_of :lastname, :firstname
>   has_one :visibility
> end
> 
> edit.rhtml (excerpt)
> <%= text_field ''user'', ''lastname'' 
%>
> <%= check_box ''visibility'',
''lastname'', {}, "public", "admin" %>
</p>
> 
> 
> I am desperately trying to make that work. Any ideas?
> 
> Best regards,
>  Dominik
You might want to post your "update" action from users_controller,
too.
It''s hard to tell what happens exactly without that.

Jeff Coleman

-- 
Posted via http://www.ruby-forum.com/.

Jeff Coleman wrote:
> Dominik wrote:
> 
>> users_controller.rb:
>> 
>> def edit
>>   @user = User.find(params[:id])
>>   @visibility = @user.visibility
>> end
>> 
>> user.rb
>> class User < ActiveRecord::Base
>>   validates_presence_of :lastname, :firstname
>>   has_one :visibility
>> end
>> 
>> edit.rhtml (excerpt)
>> <%= text_field ''user'',
''lastname''  %>
>> <%= check_box ''visibility'',
''lastname'', {}, "public", "admin" %>
</p>
> 
> You might want to post your "update" action from
users_controller, too.
> It''s hard to tell what happens exactly without that.

Here you are:

def update
  @user = User.find(params[:id])
  @user.create_visibility(params[:visibility]) unless @user.visibility
  @visibility = @user.visibility
  if @user.update_attributes(params[:user]) && 
@user.visibility.update_attributes(params[:visibility]) then
    flash[:notice] = ''Update was successful.''
    redirect_to :action => ''show'', :id => @user
  else
    render :action => ''edit''
  end
end

And here is the relevant form-tag from the view, but that is quite 
obvious:
<%= start_form_tag :action => ''update'', :id => @user
%>

Thanks in advance!

Dominik

-- 
Posted via http://www.ruby-forum.com/.

Hi all,

I just wanted to tell you how delighted I am now: I have found the bug 
after one night''s sleep - stupid me!

It had nothing to do with the edit or update action (which I posted 
above) but with the new/create actions: the line @visibility = 
@user.visibility was missing and consequently the new action could not 
fill in the checkboxes after a failed update from the instance variable 
@visibility.

For all the newbies in the world I just want to explicitly state that 
the validations take place while update_attributes is running. If any 
validations fail update_attributes returns false and you can control 
what happens next with a call to render :action or redirect to :action.


Rails rocks!

-- 
Posted via http://www.ruby-forum.com/.