Question

In our rails 3.1.4 app, there are user (parent) and user_levels (child) models.

class User < ActiveRecord::Base
  attr_accessible :name, :login, :password, :user_levels_attributes, :as => :role_new
  has_many :user_levels
  ccepts_nested_attributes_for :user_levels, :allow_destroy => true, :reject_if => proc { |a| a['position'].blank? }
  validates_associated :user_levels
end

class UserLevel < ActiveRecord::Base
  belongs_to :user
  validates_presence_of :position
end

The position column in user_level has to be filled. If it is not, both user and user_levels should NOT be saved. The problem with the above is that it always causes error of “position can’t be blank” even there is a position value in the params.

{"utf8"=>"✓",
 "user"=>{"name"=>"tester ceo",
 "login"=>"testceo",
 "update_password_checkbox"=>"[FILTERED]",
 "password"=>"[FILTERED]",
 "password_confirmation"=>"[FILTERED]",
 "user_levels_attributes"=>{"1339886115748"=>{"position"=>"ceo"}}},
 "commit"=>"Save"}

After deleting user_levels_attribues, the model saves user into users table no matter what kind of user_levels is filled int. We did extensive online search and haven’t found a solution yet. For example, if validates_presence_of :user_levels is added to the user model, then none of the user levels can be saved or updated, even with a valid position.

Any suggestion about how to implement the orchestrated saving/updating of two associated models? Thanks so much.

UPDATE:
_user_level.html.erb:

<div class="fields">
  <%= f.input :position, :collection => return_position, :prompt => "Choose position", 
                      :label => false, :include_blank => true, :selected => i_id %>
  <%= link_to_remove_fields "remove", f %>
</div>

_form_new.html.erb:

<%= simple_form_for @user do |f| %>
  <%= f.input :name, :label => 'name：' %>
  <%= f.input :login, :label => 'login：', :hint => '6 digits ' %>
  <%= f.input :password, :label => 'password：', :hint => '6digits', :input_html => {:id => 'new_user_password'} %>
  <%= f.input :password_confirmation, :label => 'confirmation：' %>  
  <%= f.input :user_type, :label => 'user type：', :collection => return_user_type, :include_blank => true %>
  &nbsp;&nbsp;position：
  <p><%= link_to_add_fields "Choose position", f, :user_levels %></p>

  <p><%= f.button :submit, 'Save' %></p>
<% end %>

Here is the method to add position field:

  #add user position in system user creation
  def link_to_add_fields(name, f, association)
    new_object = f.object.class.reflect_on_association(association).klass.new
    fields = f.fields_for(association, new_object, :child_index => "new_#{association}") do |builder|
      render :partial => association.to_s, :locals => {:f => builder, :i_id => 0} 
    end
    link_to_function(name, "add_fields(this, \"#{association}\", \"#{j fields}\")")
  end

JS file:

function add_fields(link, association, content) {
  var new_id = new Date().getTime();
  var regexp = new RegExp("new_" + association, "g")
  $(link).parent().before(content.replace(regexp, new_id));
}

Answer 1

I think you need to remove the :reject_if and change validates_associated :user_levels to validates_presence_of :user_levels.