Nested form validation in Rails - ruby-on-rails

Question

I have the following code:
<%= form_with(model: [#lawsuit, #lawsuit.suits.build]) do |f| %>
<fieldset>
<legend>New Suit</legend>
</fieldset>
<br />
<div class="form-group">
<%= f.label :claim %>
<%= f.text_field :claim, class: 'form-control', placeholder: 'Name' %>
</div>
<div class="form-group">
<%= f.label :sentence %>
<%= f.text_area :sentence, class: 'form-control', placeholder: 'Sentence' %>
</div>
<div class="form-group">
<%= f.label :result %>
<%= f.select(:result, [['Not Favorable', false], ['Favorable', true]], {}, {class: 'form-control'}) %>
</div>
<%= button_tag type: 'submit', class: "btn btn-primary float-right" do %>
<i class="fa fa-plus" aria-hidden="true"></i>
Create
<% end %>
<% end %>
How can I show the list of errors of the suit (which is a nested attribute of #lawsuit) and show it's errors on the screen ? I have already done the validations on the model. The model is like that:
class Suit < ApplicationRecord
belongs_to :lawsuit
validates_presence_of :claim, :sentence
end
My controllers are like below.
The process start in lawsuit controller. There I build the #suit (which is used in the form).
Suit controller:
class SuitsController < ApplicationController
before_action :set_suit, only: [:show]
def new
end
def create
Rails.logger.info "=====================SUIT CREATION"
#lawsuit = Lawsuit.find(params[:lawsuit_id])
#suit = #lawsuit.suits.build(suit_params)
Rails.logger.info "AISHA #{#suit.errors.any?}"
# #suit = #lawsuit.suits.new(suit_params)
if #suit.save
flash[:notice] = "Suit created successfully"
redirect_to lawsuit_path(#lawsuit)
else
Rails.logger.info "AISHA #{#suit.valid?}"
flash[:alert] = "Something went wrong"
redirect_to lawsuit_path(#lawsuit)
end
end
Lawsuit Controller
class LawsuitsController < ApplicationController
before_action :set_lawsuit, only: [:show]
def index
#lawsuits = Lawsuit.paginate(:page => params[:page], :per_page => 8)
end
def show
begin
#blob = Lawsuit.get_blob_for_document(#lawsuit.document_number)[1]
rescue
#blob = "Cannot load document!"
flash[:error] = "Cannot load document!"
end
#lawsuit = Lawsuit.find(params[:id])
#suit = #lawsuit.suits.build
end
private
def set_lawsuit
#lawsuit = Lawsuit.find(params[:id])
end
def lawsuit_params
params.require(:lawsuit).permit(:document_number, :region, :court, :noted)
end
end

Answer 1

Modify view as follows
<%= form_with(model: [:lawsuit, #suit]) do |f| %>
<fieldset>
<legend>New Suit</legend>
</fieldset>
<br />
<% if #suit.errors.any? %>
<div id="error_explanation">
<h2>
<%= pluralize(#suit.errors.count, "error") %>
<%= "prohibited this suit from being saved:" %>
</h2>
<ul></ul>
<% #suit.errors.full_messages.each do |message| %>
<li>
<%= message %>
</li>
<% end %>
</div>
<% end %>
<div class="form-group">
<%= f.label :claim %>
<%= f.text_field :claim, class: 'form-control', placeholder: 'Name' %>
</div>
<div class="form-group">
<%= f.label :sentence %>
<%= f.text_area :sentence, class: 'form-control', placeholder: 'Sentence' %>
</div>
<div class="form-group">
<%= f.label :result %>
<%= f.select(:result, [['Not Favorable', false], ['Favorable', true]], {}, {class: 'form-control'}) %>
</div>
<%= button_tag type: 'submit', class: "btn btn-primary float-right" do %>
<i class="fa fa-plus" aria-hidden="true"></i>
Create
<% end %>
<% end %>
note you should build #suit object from controller action first
#suit = #lawsuit.suits.build
and you controller should be
class SuitsController < ApplicationController
before_action :set_suit, only: [:show]
def new
end
def create
#lawsuit = Lawsuit.find(params[:lawsuit_id])
#suit = #lawsuit.suits.build(suit_params)
if #suit.save
flash[:notice] = "Suit created successfully"
redirect_to lawsuit_path(#lawsuit)
else
render :form
end
end
Or
If you want to display flash message then you should write following code on view
<% flash.each do |key, value| %>
<div class="alert alert-<%= key %>"><%= value %></div>
<% end %>