Contact and Address saving with Rails 5

_address.html.erb

<% prefix = "contact_address" %>                                                                    
<%= fields_for prefix, @address do |address_form| -%>                                               
  <div class="field">                                                                               
    <%= address_form.label :name %>                                                                     
    <%= address_form.text_field :name, id: :address_name %>                                           
    </div>                                                                                                                                                                                                
  <div class="field">                                                                                   
  <%= address_form.label :street %>                                                                   
  <%= address_form.text_field :street, id: :address_street %>                                       
  </div>                                                                                                                                                                                                
  <div class="field">                                                                               
    <%= address_form.label :city %>                                                                 
    <%= address_form.text_field :city, id: :address_city %>                                         
  </div>                                                                                            
                                                                                                    
  <div class="field">                                                                               
    <%= address_form.label :state %>                                                                
    <%= address_form.text_field :state, id: :address_state %>                                       
  </div>      
  
   <div class="field">                                                                               
    <%= address_form.label :zip %>                                                                  
    <%= address_form.text_field :zip, id: :address_zip %>                                           
  </div>                                                                                            
                                                                                                    
  <div class="field">                                                                               
    <%= address_form.label :country %>                                                              
    <%= address_form.text_field :country, id: :address_country %>                                   
  </div>                
  
    <div class="field">                                                                               
    <%= address_form.label :primary %>                                                              
    <%= address_form.check_box :primary, id: :address_primary %>                                    
  </div>                                                                                            
                                                                                                    
<% end %>  

_form.html.erb

<%= form_with(model: contact, local: true) do |form| %>
<% if contact.errors.any? %>                                                                          
<div id="error_explanation">                                                                          
<h2><%= pluralize(contact.errors.count, "error") %> prohibited this contact from being saved  :</h2>                                                                                                                                                                                                        <ul>                                                                                                <% contact.errors.full_messages.each do |message| %>                                                  <li><%= message %></li>                                                                           <% end %>                                                                                           </ul>                                                                                       
</div>                                                                                        
    <% end %>                                                                                                                                                                                           
    <%= form.hidden_field :list_id, id: :contact_list_id, value: @list.id %>                                                                                                                            
    <div class="field">                                                                             
      <%= form.label :name %>                                                                             
      <%= form.text_field :name, id: :contact_name %>                                               
    </div>                                                                                                                                                                                              
    <div class="field">                                                                             
      <%= form.label :active %>                                                                     
      <%= form.check_box :active, id: :contact_active %>                                            
    </div>                                                                                          
                                                                                                    
    <%= render "contacts/address" %>                                                                                                                                                    
    <div class="field">                                                                                   
    <%= form.label :comment %>                                                                          
    <%= form.text_area :comment, id: :contact_comment %>     
     </div>                                                                                          
                                                                                                    
    <div class="actions">                                                                           
      <%= form.submit %>                                                                                
      </div>                                                                                          
  <% end %>

contacts_controller.erb

def create                                                                                      
      @contact = Contact.new(contact_params)                                                        
                                                                                                          
      respond_to do |format|                                                                                
        if @contact.save                                                                                    
          @contact_address = @contact.addresses.build(contact_address_params)                               
          @contact_address.save                                                                               
          format.html { redirect_to @contact, notice: 'Contact was successfully created.' }         
          format.json { render :show, status: :created, location: @contact }                        
        else                                                                                        
          format.html { render :new }                                                               
          format.json { render json: @contact.errors, status: :unprocessable_entity }               
        end                                                                                         
      end                                                                                           
    end

...

# Never trust parameters from the scary internet, only allow the white list through.                
  def contact_params                                                                                    
    params.require(:contact).permit(:list_id, :name, :active, :comment)                               
  end                                                                                   
  def contact_address_params                                                                        
    params.permit(:contact_address).permit(:name, :street, :city, :state, :zip, :country, :primary)              
  end 

gistfile1.txt

class Contact < ApplicationRecord                                                                 
    belongs_to :list                                                                                
    has_many :addresses                                                                             
    has_many :contact_meta                                                                                                                                                                                                                                                               
  end