Rails nested form attributes not showing on edit - ruby-on-rails

Question

I'm working on an app that has and agency which has many branches and both the agency and the branches can have addresses. I have created the models for them as shown below:
# agency.rb
has_many :branches
has_one :address
accepts_nested_attributes_for :branches, reject_if: :all_blank, allow_destroy: true
accepts_nested_attributes_for :address, reject_if: :all_blank, allow_destroy: true
# branch.rb
belongs_to :agency
has_one :address
accepts_nested_attributes_for :address, reject_if: :all_blank
# address.rb
belongs_to :agency
belongs_to :branch
I have an agency form which should allow me to create/edit an agency and it's address as well as add/edit/delete branches and their addresses too.
Here is the agency form:
<%= form_for(#agency) do |f| %>
<div class="box-body">
# errors and messages etc etc ...
<div class="field">
<%= f.label :name %><br>
<%= f.text_field :name, class: 'form-control' %>
</div>
# more agency fields
<%= f.fields_for :address do |address| %>
<%= render 'addresses/address_fields', f: address %>
<% end %>
#other fields which all work fine
<div id="branches">
<%= f.fields_for :branches do |branch| %>
<%= render 'branch_fields', f: branch %>
<% end %>
<div class="links">
<%= link_to_add_association 'add branch', f, :branches %>
</div>
</div>
</div>
<%= f.submit 'Save Changes', class: 'btn btn-primary' %>
<% end %>
Here are the branch fields (partial form):
# branch name ...
<div class="field">
<%= f.label :name %>
<%= f.text_field :name %>
</div>
# I will explain this bit below
<% if f.object.new_record? %>
<% f.object.build_address %>
<% end %>
###
<%= f.fields_for :address do |address| %>
<%= render 'addresses/address_fields', f: address %>
<% end %>
# other branch fields that work fine
<%= link_to_remove_association "remove branch", f %>
And here is the agencies controller:
class AgenciesController < ApplicationController
before_action :authenticate_user!
before_action :set_agency, only: [:show, :edit, :update]
# before_action :build_address, only: [:new, :edit]
def index
#agencies = Agency.all
end
def show
end
def create
#agency = Agency.new(agency_params)
respond_to do |format|
if #agency.save
format.html { redirect_to #agency, notice: 'Agency was successfully created.' }
format.json { render :show, status: :created, location: #agency }
else
format.html { render :new }
format.json { render json: #agency.errors, status: :unprocessable_entity }
end
end
end
def new
#agency = Agency.new
#agency.build_address
#agency.build_domain_name
#agency.branches.build
#agency.services.build
# #agency.branches.build_addresses
# #agency.branches.each do |branch|
# branch.build_address
# end
end
def edit
end
def update
respond_to do |format|
if #agency.update(agency_params)
format.html { redirect_to #agency, notice: 'Agency was successfully updated.' }
format.json { render :show, status: :ok, location: #agency }
else
format.html { render :edit }
format.json { render json: #agency.errors, status: :unprocessable_entity }
end
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_agency
#agency = Agency.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def agency_params
params.require(:agency).permit(:name, :logo, :description, :phone_number, :alt_phone_number, :email, :alt_email,
services_attributes:
[:id, :name, :description, :_destroy],
address_attributes:
[:id, :first_line, :second_line, :third_line, :city_town, :post_code, :_destroy],
domain_name_attributes:
[:id, :domain],
branches_attributes:
[:id, :name, :description, :phone_number, :alt_phone_number, :_destroy, :email, :alt_email,
services_attributes:
[:id, :name, :description, :_destroy],
address_attributes:
[:id, :first_line, :second_line, :third_line, :city_town, :post_code, :_destroy]
]
)
end
end
Apologies for the lengthy code.
The problem I was facing initially was that when I was adding a new branch, the address fields were not showing up. After some digging, I found a question on SO where someone suggested running f.object.build_address
just before calling the fields for the branch. This worked fine for creating a new branch on the agency form but after saving, and returning to the edit agency page, the address fields for the branch were blank. However, the address was saved correctly to teh database. I think this was caused bu the build_address line overriting the content when editing which is why I attempted to wrap it in the if loop but I'm almost certain this is wrong.
How can I correctly build the nested branch address attributes in the controller so that the fields are shown correctly when adding a new agency and or branch? And how can I ensure that the saved values are displayed correctly when I come back to edit the agency and branch(es) later.
I have done a lot of reading and digging and I cant see any of the normal issues like wrong tags used (<%= / <%) to no avail. Any help would be most appreciated.

Answer 1

Try with these modifications:
<%= f.fields_for #agency.address do |address| %>
<%= render 'addresses/address_fields', f: address %>
<% end %>
#other fields which all work fine
<div id="branches">
<%= f.fields_for #agency.branches do |branch| %>
<%= render 'branch_fields', f: branch %>
<% end %>