Ruby on Rails 4.2中的嵌套表单无法识别来自fields_for的参数

Question

undefined method `hname' for #<Wife:0x007f1eb7f91230> Did you mean? wname

Hi! I'm new to ruby and am learning how to make a nested form manually and not using a scaffold for about 1 week now and still couldnt find a way to make it, i've done lots of research but still couldn't find the right solution. Please help me know what are my problems and missing syntax. Thanks in advance!

here is my tables:

    mysql> desc husbands;
+------------+--------------+------+-----+---------+----------------+
| Field      | Type         | Null | Key | Default | Extra          |
+------------+--------------+------+-----+---------+----------------+
| id         | int(11)      | NO   | PRI | NULL    | auto_increment |
| hname      | varchar(255) | YES  |     | NULL    |                |
| wife_id    | int(11)      | YES  | MUL | NULL    |                |
| kabet_id   | int(11)      | YES  | MUL | NULL    |                |
| created_at | datetime     | NO   |     | NULL    |                |
| updated_at | datetime     | NO   |     | NULL    |                |
+------------+--------------+------+-----+---------+----------------+
6 rows in set (0.01 sec)

mysql> desc wives;
+------------+--------------+------+-----+---------+----------------+
| Field      | Type         | Null | Key | Default | Extra          |
+------------+--------------+------+-----+---------+----------------+
| id         | int(11)      | NO   | PRI | NULL    | auto_increment |
| wname      | varchar(255) | YES  |     | NULL    |                |
| created_at | datetime     | NO   |     | NULL    |                |
| updated_at | datetime     | NO   |     | NULL    |                |
+------------+--------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)

mysql> desc kabets;
+------------+--------------+------+-----+---------+----------------+
| Field      | Type         | Null | Key | Default | Extra          |
+------------+--------------+------+-----+---------+----------------+
| id         | int(11)      | NO   | PRI | NULL    | auto_increment |
| kname      | varchar(255) | YES  |     | NULL    |                |
| created_at | datetime     | NO   |     | NULL    |                |
| updated_at | datetime     | NO   |     | NULL    |                |
+------------+--------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)

Here are my codes:

wife.rb

class Wife < ActiveRecord::Base
    has_one :husband

    accepts_nested_attributes_for :husband
    validates_presence_of :hname
end

husband.rb

class Husband < ActiveRecord::Base
    belongs_to :wife
    belongs_to :kabet

    accepts_nested_attributes_for :wife
end

kabet.rb

class Kabet < ActiveRecord::Base
    has_one :husband

    accepts_nested_attributes_for :husband
end

husbands controller:

class HusbandsController < ApplicationController
  def index
    @husbands = Husband.all
  end

  def show
    @husband = Husband.find(params[:id])
  end

  def new
    @husband = Husband.new
    @husband.build_wife
    @husband.build_kabet
  end

  def create
    @husband = Husband.new(husband_params)
    @husband.build_wife
    @husband.build_kabet
    @husband.save
    redirect_to action: "show"
  end

  private
  def husband_params
    params.require(:husband).permit(:hname, :wife_id, :kabet_id, wife_attributes:[:id,:wname], kabets_attributes:[:id,:kname])
  end
end

wives controller:

class WivesController < ApplicationController
  def index
    @wives = Wife.all
  end

  def new
    @wife = Wife.new
    @wife.build_husband
  end

  def create
    @wife = Wife.new(wife_params)
   #@wife.build_husband
    @wife.save
    redirect_to action: "index"
  end

  def show
  end

  private
  def wife_params
    params.require(:wife).permit(:id,:wname, husband_attributes: [:id,:hname])
  end
end

view form for husband:

<%= form_for @husband do |f| %>
<table>
    <tr>
        <th>Name ng Husband</th>
        <th>Name ng Legal Wife</th>
        <th>Name ng Kabet</th>
    </tr>
    <tr>
        <td><%= f.text_field :hname %></td>
        <%= f.fields_for :wife do |wife| %>
        <td><%= wife.text_field :wname %></td>
        <% end %>
        <%= f.fields_for :kabets do |kabet| %>
        <td><%= kabet.text_field :kname %></td>
        <% end %>
    </tr>

<%= f.submit %>   
</table>
<% end %>

view form for wives:

<%= form_for @wife do |f| %>
<table>
    <tr>
        <th><%= f.label :wname %></th>
        <td><%= f.text_field :wname %></td>
    </tr>
    <%= f.fields_for :husbands do |ff| %>
    <tr>
        <th><%= ff.label :hname %></th>
        <td><%= ff.text_field :hname %></td>
    <% end %>
    </tr>
</table>
<%= f.submit %>
<% end %>

It doesnt matter even if i create on husband's form or on wives' form, i still encounter this error:

undefined method `hname' for #<Wife id: nil, wname: "zzxc", created_at: nil, updated_at: nil> Did you mean? wname

Extracted source (around line #14):

Answer 1

In your Wife model, you have mentioned validates_presence_of :hname but you dont have a hname in Wife table. It is in husband table. That is why it is giving that error.

Instead, you can move that validation to Husband model and in Wife model use:

validates_associated: husband if you really want to validate hanme name before saving wife object.

Please note that , I have not checked your codes for any other possible mistakes in nested form setup. Fix this error first and then you can proceed further, step by step.

Answer 2

In your WivesController why do you have #@wife.build_husband commented. That alone is one source of your problems. Uncomment that line and everything should be fine. If it doesn't work try the following

1. Use pry in your wives view and try to call its association on it like this @wives.husband if you get nil, then you will have to build the association like this @wives.build_husband . I know you have already built this in the controller, but for debugging sake, try it building in on the view and see how things go.

2. validates_presence_of :hname should be done in the Husband model not in the Wife model. Alternatively you can validate the presence of hname for nested attributes like this

accepts_nested_attributes_for :husband, reject_if: proc { |attributes| attributes['hname'].blank? }

Hope this helps you out.