Displaying items captured via a nested form - ruby-on-rails

Question

I'm trying to build a small expense tracking app. Using the nested_form gem to add line items. There is an Expense model which accepts nested attributes. Items belong to expenses and there is a foreign key association. Here's the expense controller:
class ExpensesController < ApplicationController
def new
#expense = Expense.new
#item = #expense.items.build
end
def index
#expenses = Expense.all
##items = Item.where(:expense_id => #expense.id)
end
def show
#expense = Expense.find(params[:id])
#items = Item.where(:expense_id => #expense.id)
end
def create
#expense = Expense.new(expense_params)
respond_to do |format|
if #expense.save
format.html { redirect_to #expense, notice: 'Expense Report Submitted.' }
format.json { render :show, status: :created, location: #expense }
else
format.html { render :new }
format.json { render json: #expense.errors, status: :unprocessable_entity }
end
end
end
def edit
#expense = Expense.find(params[:id])
end
def update
#expense = Expense.find(params[:id])
if #expense.save(expense_params)
flash[:notice] = "Expense Report Updated"
redirect_to #expense
else
render 'edit'
end
end
def destroy
#expense = Expense.find(params[:id])
#expense.destroy
redirect_to 'root'
end
private
def expense_params
params.require(:expense).permit(:department_id, :expense_type_id, :notes, items_attributes: [:id, :description, :amount, :issue_date, :_destroy])
end
end
The form looks like:
<%= nested_form_for (#expense) do |f| %>
<% if #expense.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#expense.errors.count, "error") %> prohibited
this expense from being saved:</h2>
<ul>
<% #expense.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class"row">
<div class="col-md-8">
<div class="form-group">
<%= f.label :department_id %><br>
<%= f.collection_select(:department_id, Department.all, :id, :department_name, prompt: true, class: "dropdown-menu") %>
</div>
<div class="form-group">
<%= f.label :expense_type_id %><br>
<%= f.collection_select(:expense_type_id, ExpenseType.all, :id, :expense_name, prompt: true, class: "form-control") %>
</div>
<%= f.fields_for :items do |i| %>
<div class="form-group">
<%= i.label :description%>
<%= i.text_field :description, class: "form-control" %>
</div>
<div class="form-group">
<%= i.label :amount%>
<%= i.text_field :amount, class: "form-control" %>
</div>
<div class="form-group">
<%= i.label :issue_date%>
<%= i.date_select :issue_date, class: "form-control" %>
</div>
<%= i.link_to_remove "Remove", class: "btn btn-default" %>
<% end %>
<div><p><%= f.link_to_add "Add Expense", :items, class: "btn btn-default" %></p></div>
<div class="form-group">
<%= f.label :notes %>
<%= f.text_area :notes, class: "form-control" %>
</div>
<%= f.submit "Submit", class: "btn btn-primary" %>
<% end %>
</div>
</div>
When I hit submit, the expense and items are saved. I checked with Sqlite browser and the foreign key values are captured for each item.
The index file looks like:
<% #expenses.each do |expense| %>
<tr>
<td><%= expense.item.description %></td>
<td><%= number_to_currency(expense.item.amount) %></td>
<td><%= expense.item.issue_date %></td>
<% end %>
I tried the usual combinations (like expense.item.description) by passing through a block, but they aren't working. I would like to know how to display the expense and the associated items in the show and index pages.

Answer 1

Looking at your new action, in your models you would have
class Expense < ActiveRecord::Base
has_many :items
accepts_nested_attributes_for :items
end
So when you are doing expense.items in your view it gives you an active record relation(since expense has many items), try this:
<% #expenses.each do |expense| %>
<% expense.items.each do |item| %>
<tr>
<td><%= item.description %></td>
<td><%= number_to_currency(item.amount) %></td>
<td><%= item.issue_date %></td>
</tr>
<% end %>
<% end %>