error message passed through to front end

app/controllers/case_logs_controller.rb

@@ -24,21 +24,27 @@ class CaseLogsController < ApplicationController
   def next_page
     form = Form.new(2021, 2022)
     @case_log = CaseLog.find(params[:case_log_id])
+    
     previous_page = params[:previous_page]
     questions_for_page = form.questions_for_page(previous_page).keys
     answers_for_page = page_params(questions_for_page).select { |k, _v| questions_for_page.include?(k) }
-    if @case_log.valid?
+
+    @case_log_temp = CaseLog.new(answers_for_page)
+    if @case_log_temp.valid?
       @case_log.update!(answers_for_page)
       next_page = form.next_page(previous_page)
       redirect_to(send("case_log_#{next_page}_path", @case_log))
+    else
+      @errors = @case_log_temp.errors.full_messages
+      redirect_to(send("case_log_#{previous_page}_path", @case_log, errors: @errors))
     end
   end
 
   form = Form.new(2021, 2022)
   form.all_pages.map do |page_key, page_info|
-    define_method(page_key) do
+    define_method(page_key) do |errors = {}|
       @case_log = CaseLog.find(params[:case_log_id])
-      render "form/page", locals: { case_log_id: @case_log.id, form: form, page_key: page_key, page_info: page_info }
+      render "form/page", locals: { case_log_id: @case_log.id, form: form, page_key: page_key, page_info: page_info, errors: errors }
     end
   end
 

app/models/case_log.rb

@@ -5,13 +5,14 @@ class CaseLogValidator < ActiveModel::Validator
     elsif record.tenant_age > 120
       record.errors.add :base, "Age needs to be below 120"
     end
-    binding.pry
   end
 
   def validate(record)
+    if record.tenant_age?
       validate_tenant_age(record)
     end
   end
+end
 
 class CaseLog < ApplicationRecord
   enum status: { "in progress" => 0, "submitted" => 1 }

app/views/form/page.html.erb

@@ -6,12 +6,17 @@
 <% end %>
 
 <%= turbo_frame_tag "case_log_form", target: "_top" do %>
+
   <% if page_info["header"].present? %>
     <h1 class="govuk-heading-xl">
       <%= page_info["header"] %>
     </h1>
   <% end %>
   <%= form_with action: '/case_logs', method: "next_page", builder: GOVUKDesignSystemFormBuilder::FormBuilder do |f| %>
+    <% if params[:errors].present? %>
+      <%= params[:errors] %>
+      <%= f.govuk_error_summary 'Uh-oh, spaghettios' %>
+    <% end %>
 
     <% page_info["questions"].map do |question_key, question| %>
       <%= render partial: "form/#{question["type"]}_question", locals: { question_key: question_key, question: question, f: f } %>