rails multi-level nested forms with cocoon and tables - ruby-on-rails

Question

I've successfully implemented one level of nested form with Cocoon and tables. However, I'm having a difficult time wrapping my mind on how to do another nested level. My issue is how to do this with a table. And maybe a table isn't the write way to go at all. Thank you for helping a newbie.
Here are my models:
class Profession < ApplicationRecord
has_many :procedure_categories, dependent: :destroy
accepts_nested_attributes_for :procedure_categories, allow_destroy: true
end
And:
class ProcedureCategory < ApplicationRecord
belongs_to :profession
has_many :procedures
accepts_nested_attributes_for :procedures, allow_destroy: true
end
And:
class Procedure < ApplicationRecord
belongs_to :procedure_category
end
Here is my top level form code:
<%= form_for(#profession) do |f| %>
<%= render 'shared/profession_error_messages' %>
<%= f.label :profession %>
<%= f.text_field :profession, class: 'form-control' %>
<%= f.label :description %>
<%= f.text_field :description, class: 'form-control' %>
<%= f.label :active, class: "checkbox inline" do %>
<%= f.check_box :active %>
<span>Active profession?</span>
<% end %>
<table class='table'>
<thead>
<tr>
<th>Category</th>
<th>Description</th>
<th>Display Order</th>
<th>Selection Type</th>
<th>Delete</th>
<th>Edit</th>
</tr>
</thead>
<tbody class="categories">
<%= f.fields_for :procedure_categories do |procedure_category| %>
<%= render 'procedure_category_fields', f: procedure_category %>
<% end %>
</tbody>
</table>
<%= link_to_add_association 'Add Category', f, :procedure_categories,
data: { association_insertion_node: '.categories', association_insertion_method: :append } %>
<br><br>
<%= f.submit "Save", class: "btn btn-primary" %>
<% end %>
And the next partial one level down:
<tr class="nested-fields">
<td><%= f.text_field :category, class: 'form-control' %></td>
<td><%= f.text_field :description, class: 'form-control' %></td>
<td><%= f.text_field :display_order, class: 'form-control' %></td>
<% cs = options_for_select(controls, f.object.selection_type) %>
<td><%= f.select :selection_type, cs, class: 'form-control' %></td>
<td><%= link_to_remove_association "Remove Category", f %></td>
<% if f.object != nil %>
<td><%= link_to "Category", edit_procedure_category_path(#profession,f.object) %><td></td>
<% end %>
</tr>
So, I'm struggling with how to implement the final level of nesting (procedures).
Thank you for listening.

Answer 1

Use has_many :through
Here are my models:
class Profession < ApplicationRecord
has_many :procedures, through: categories
has_many :categories, dependent: :destroy
accepts_nested_attributes_for :categories, allow_destroy: true
end
Rename this procedure_category model in category
class Category < ApplicationRecord
belongs_to :profession
has_many :procedures
accepts_nested_attributes_for :procedures, allow_destroy: true
end
And:
class Procedure < ApplicationRecord
belongs_to :category
end
If I miss something you can check the instruction from the rails guide
The controller professions#new action should create the following variables, so that they are available in the view:
def new
#profession = Profession.new
#categories = #profession.categories.build
#procedures = #categories.procedures.build
end
The view uses that variable so store the user inputs and make a post request at /profession/ with those inputs stored in the parameters hash
<%= form_for(#profession) do |f| %>
<%= f.fields_for :categories do |category| %>
<%= category.fields_for :procedures do |precedure| %>
<% end %>
<% end %>
<% end %>
The fields_for yields a form builder. The parameters' name will be what accepts_nested_attributes_for expects. For example, when creating a user with 2 addresses, the submitted parameters would look like:
This is how your parameters should look like:
{
'profession' => {
'name' => 'John Doe',
'categories_attributes' => {
'0' => {
'kind' => 'Home',
'street' => '221b Baker Street',
'procedures_attributes' => {
'0' => {},
'1' => {}
}
},
'1' => {
'kind' => 'Office',
'street' => '31 Spooner Street'
}
}
}
}
so make sure your form is pointing at post url /professions/ and that the routing will trigger the professions#create action
def create
binding.pry
end
for any problems set a binding pry and check in your console how your parameters are showing up.
Read more at
http://guides.rubyonrails.org/form_helpers.html#building-complex-forms