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I find a solution to my problem following many SO answers. But , i'm not so comfort with Rails magic , and i would understand what happened in my web app. I explain the context:

I have two model:

class Registry < ActiveRecord::Base
  belongs_to  :profession       
  accepts_nested_attributes_for :profession 
end

class Profession < ActiveRecord::Base
  has_many  :registries
end

and a form (for registry ) with nested attributes of the profession model

<%= form_for(@registry) do |f| %>
...
    <%= f.fields_for :profession do |ff| %>
...

The problem was , that if i used: 

<%= f.fields_for :profession do |ff| %>

I didn't show the attributes of profession table. Instead ,if i used 

:professions

so:

<%= f.fields_for :professions do |ff| %>

I see the form. I don't understand why this happened but then , searching on google and on SO , I found that:

Nested attributes allow you to save attributes on associated records through the parent.

So , maybe this behaviour is caused cause I’m using nested attributes in the child table. But i would have explained better why with :professions i saw the attributes of the form and with :profession , no.

Now , i fixed the problem using this in the registries_controller:

def new
  @registry = Registry.new
  @registry.build_profession
end

I added the @registry.build_profession and now in the form i can use the singular ":profession"

I don't know what happened... Can someone explain me these two things? really, i'm not confort with Rails magic..

Also , i have a problem cause if i don't want to insert data in the part of profession form , the profession row is always created in the database. This row is linked by foreign_key to registry row , but is blank (if i don't write nothing in the form , of course). This is really unacceptable..why i have to create a row , before to check if the user put the values..this is not good. I know , nested attribute should be in the parent , but i have this necessity to use them in the child. Really, rails programmers didin't think this possibility? I programmed in rails for 6 months , it's not much, i know..but is it possible that everytime i have to fix or discover new things (completely new)??

I'm getting crazy.

EDIT: I'm serching explaination of the problem. Not to solve it.

Vito
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  • Possible duplicate of [Ruby on Rails: Nested Attributes, belongs\_to relation](http://stackoverflow.com/questions/1593853/ruby-on-rails-nested-attributes-belongs-to-relation) – lorefnon Oct 24 '15 at 14:32
  • I'm serching explaination of the problem. Not to solve it. – Vito Oct 24 '15 at 14:40
  • So " This appears to be a documented bug" . Is this meaning that nobody know the answer to my question? – Vito Oct 24 '15 at 15:05

1 Answers1

0

Actually, since you're using the has_many association, your controller should be:

   def new
     @registry = Registry.new
     @registry.profession.build
   end
Vinicius Martinson
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