Nested attributes for belongs_to association rails

问题

I have two models, Complaint and Company. Complaint belongs_to and accepts_nested_attributes for Company, and Company has_many Complaints.

# Models

class Complaint < ActiveRecord::Base
  attr_accessible :complaint, :date, :resolved

  belongs_to :user, :class_name => 'User', :foreign_key => 'id'
  belongs_to :company, :class_name => 'Company', :foreign_key => 'id'
  has_many :replies

  accepts_nested_attributes_for :company

end

class Company < ActiveRecord::Base
  attr_accessible :name

  has_many :complaints, :class_name => 'Complaint', :foreign_key => 'id'
  has_many :branches, :class_name => 'Branch', :foreign_key => 'id'
  belongs_to :industry

end

In the Complaint Controller I try build a Company in the new method.

# Complaint Controller

class ComplaintsController < ApplicationController
...
def new
    @complaint = Complaint.new
    @complaint.build_company

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @complaint }
    end
  end
...
end

In the form I have added a field for adding a name attribute to the Company.

# Complaint Form

<%= form_for(@complaint) do |f| %>
  <% if @complaint.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@complaint.errors.count, "error") %> prohibited this complaint from being saved:</h2>

      <ul>
      <% @complaint.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :complaint %><br />
    <%= f.text_area :complaint, :rows => 5 %>
  </div>
  <div class="field">
    <%= f.label :date %><br />
    <%= f.datetime_select :date %>
  </div>

  <% if current_user.try(:admin?) %>
    <div class="field">
      <%= f.label :resolved %><br />
      <%= f.check_box :resolved %>
    </div>
  <% end %>

  <%= fields_for :company do |company| %>
    <div class="field">
      <%= company.label :name, 'Company' %>
      <%= company.text_field :name %>
    </div>
  <% end %>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

The form submits but only the Complaint is saved. The user input for Company is disregarded. Why won't this create a new Company?

回答1:

My mistake was in the form. I missed the f. before the fields_for :company

<%= f.fields_for :company do |company| %>

来源：https://stackoverflow.com/questions/15471104/nested-attributes-for-belongs-to-association-rails