Rails - Aug 2009 - unable to create record with has_mant :through relationship

hi all,

i have a has_many :through r''ship in my application. my tables are -
users, apps(short form for applications), categorizations. i''m trying
to
create a user in new.rhtml where all apps are also shown in checkboxes
for selection. on submit, user gets created but the join table i.e.
categorizations table doesn''t get updated. where am i going wrong?
doesn''t the join table gets updated automatically? or do i''ve
to update
it manually? if yes, how? Any help will be greatly appreciated. thanks
in advance.

code:

class App < ActiveRecord::Base
  has_many :categorizations
  has_many :users, :through => :categorizations
end

class User < ActiveRecord::Base
  has_many :categorizations
  has_many :apps, :through => :categorizations
end

class Categorization < ActiveRecord::Base
  belongs_to :user
  belongs_to :app
end

class UsersController < ApplicationController
  def new
    @user = User.new
    @apps = App.find(:all)
  end

  def create
    @user = User.new(params[:user])
    @user.save!
    redirect_to(:action => "new")
    flash[:notice] = "Thanks for signing up!"
    rescue ActiveRecord::RecordInvalid
    render :action => ''new''
  end
end

users/new.rhtml
<%= error_messages_for :user %>
<% form_for :user, :url => users_path do |f| -%>
<p><label for="login">Login</label><br/>
<%= f.text_field :login %></p>

<p><label for="email">Email</label><br/>
<%= f.text_field :email %></p>

<p><label for="password">Password</label><br/>
<%= f.password_field :password %></p>

<p><label for="password_confirmation">Confirm
Password</label><br/>
<%= f.password_field :password_confirmation %></p>

<p><label
for="password_confirmation">Applications</label><br/>
<%for app in @apps%>
    <%= check_box_tag "user[app_ids][]", app.id,
@user.apps.include?(app)%> <%=app.name%><br/>
<%end%>
</p>

<p><%= submit_tag ''Sign up'' %></p>
<% end -%>

log:
Parameters:
{"user"=>{"password_confirmation"=>"aaaa",
"app_ids"=>["1",
"2", "3", "4"],
"login"=>"aaaa",
"password"=>"aaaa",
"email"=>"aaaa-MB/4cHSNlRU@public.gmane.org"},
"commit"=>"Sign up",
"action"=>"create",
"controller"=>"users"}
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Dhaval Phansalkar wrote:
> hi all,
> 
> i have a has_many :through r''ship in my application. my tables are
-
> users, apps(short form for applications), categorizations. i''m
trying to
> create a user in new.rhtml where all apps are also shown in checkboxes
> for selection. on submit, user gets created but the join table i.e.
> categorizations table doesn''t get updated. where am i going wrong?
> doesn''t the join table gets updated automatically? or do
i''ve to update
> it manually? if yes, how? Any help will be greatly appreciated. thanks
> in advance.
> 
> code:

where is your habtm?
-- 
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An User can have many applications and an App can have many users.  So I 
would think...

class App < ActiveRecord::Base
 has_and_belongs_to_many: users
end

class User < ActiveRecord::Base
  has_and_belongs_to_many: apps
end



-- 
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Rails List wrote:
> An User can have many applications and an App can have many users.  So I 
> would think...
> 
> class App < ActiveRecord::Base
>  has_and_belongs_to_many: users
> end
> 
> class User < ActiveRecord::Base
>   has_and_belongs_to_many: apps
> end
let me know how it goes

http://www.craigslistcloned.com
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Rails List wrote:
> Rails List wrote:
>> An User can have many applications and an App can have many users.  So
I
>> would think...
>> 
>> class App < ActiveRecord::Base
>>  has_and_belongs_to_many: users
>> end
>> 
>> class User < ActiveRecord::Base
>>   has_and_belongs_to_many: apps
>> end
> 
> let me know how it goes
> 
> http://www.craigslistcloned.com
yes, thats correct. but i''m going to add one more field called 
permission in the join table. so used has_many :through
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>> 
>> let me know how it goes
>> 
>> http://www.craigslistcloned.com
> 
> yes, thats correct. but i''m going to add one more field called 
> permission in the join table. so used has_many :through
Have you got a corresponding model for Categorization?.
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Rails List wrote:
> 
>>> 
>>> let me know how it goes
>>> 
>>> http://www.craigslistcloned.com
>> 
>> yes, thats correct. but i''m going to add one more field called
>> permission in the join table. so used has_many :through
> 
> Have you got a corresponding model for Categorization?.
yes. it''s in my 1st post under "code"
class Categorization < ActiveRecord::Base
  belongs_to :user
  belongs_to :app
end
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On Tue, Aug 25, 2009 at 1:45 PM, Dhaval
Phansalkar<rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
wrote:
>
> hi all,
>
> i have a has_many :through r''ship in my application. my tables are
-
> users, apps(short form for applications), categorizations. i''m
trying to
> create a user in new.rhtml where all apps are also shown in checkboxes
> for selection. on submit, user gets created but the join table i.e.
> categorizations table doesn''t get updated. where am i going wrong?
> doesn''t the join table gets updated automatically? or do
i''ve to update
> it manually? if yes, how? Any help will be greatly appreciated. thanks
> in advance.
I beleive that you need to create the categorizations yourself
something like (this is untested):
> class UsersController < ApplicationController
>  def new
>    @user = User.new
>    @apps = App.find(:all)
>  end
>
>  def create
>    @user = User.new(params[:user])
      params[:user][:app_ids].each do | app_id|
           @user.categorizations << Category.new(:app_id => app_id)
      end
>    -uQpvtAwYA0+zQB+pC5nmwQ@public.gmane.org!
>    redirect_to(:action => "new")
>    flash[:notice] = "Thanks for signing up!"
>    rescue ActiveRecord::RecordInvalid
>    render :action => ''new''
>  end
> end
HTH


-- 
Rick DeNatale

Blog: http://talklikeaduck.denhaven2.com/
Twitter: http://twitter.com/RickDeNatale
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LinkedIn: http://www.linkedin.com/in/rickdenatale

Rick Denatale wrote:
> On Tue, Aug 25, 2009 at 1:45 PM, Dhaval
>
Phansalkar<rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
wrote:
>> in advance.
> I beleive that you need to create the categorizations yourself
> something like (this is untested):
> 
>> class UsersController < ApplicationController
>> �def new
>> � �@user = User.new
>> � �@apps = App.find(:all)
>> �end
>>
>> �def create
>> � �@user = User.new(params[:user])
>       params[:user][:app_ids].each do | app_id|
>            @user.categorizations << Category.new(:app_id =>
app_id)
>       end
>> � �-uQpvtAwYA0+zQB+pC5nmwQ@public.gmane.org!
>> � �redirect_to(:action => "new")
>> � �flash[:notice] = "Thanks for signing up!"
>> � �rescue ActiveRecord::RecordInvalid
>> � �render :action => ''new''
>> �end
>> end
> Rick DeNatale
Thanks Rick. That worked. i thought join table might get updated 
automatically after mentioning the r''ship in models. only 1 change in
ur
code, Category shd be replaced with Categorization. Thanks once again :)

-DPP
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