Bulk add item rails 6 - ruby-on-rails

Question

I have a little project management app.
In the app I have a Project, Item and Delivery Model.
class Project < ApplicationRecord
has_many :locations, dependent: :destroy
has_many :items, dependent: :destroy
has_many :deliveries, dependent: :destroy
end
class Item < ApplicationRecord
belongs_to :project
belongs_to :location, optional: true
has_many :delivery_items, dependent: :destroy
has_many :deliveries, through: :delivery_items
enum status: [:unscheduled, :scheduled, :delivered]
end
class Delivery < ApplicationRecord
belongs_to :project
has_many :delivery_items, dependent: :destroy
has_many :items, through: :delivery_items
enum status: [ :unapproved, :approved, :scheduled ]
end
I also have a delivery_item join table
class DeliveryItem < ApplicationRecord
belongs_to :delivery
belongs_to :item
end
I have added a new Model called location, which is a way of classifying the items into a group on the project.
class Location < ApplicationRecord
belongs_to :project
has_many :items
has_many :part_numbers, through: :items
def bulkadd(delivery)
self.items.each do |row|
batch << Product.new(row)
end
end
end
At the moment the user individually adds items to deliveries via a form on the page
<h6>Add to Delivery</h6>
<%= form_for #delivery_item, html: {class: 'form-inline'} do |form| %>
<div class="form-group">
<%= form.collection_select :delivery_id, #project.deliveries.all, :id, :date, placeholder: 'Add to Delivery', class: 'form-control' %>
</div>
<%= form.hidden_field :item_id, value: item.id %>
<div class="form-group">
<%= form.submit "Add",class: 'btn btn-primary' %>
</div>
<% end %>
I would like to simplify the process by adding a bulk add button to each location which would add all of the associated items to the delivery selected has many items.
I know that I will need the delivery_item(delivery, item).
I just cant seem to get the final part to work in my brain

Answer 1

When you create a has_many or has_and_belongs_to_many assocation the macro creates an others_ids setter/getter. In this case item_ids= which will automatically add/remove rows from the join table.
Its really easy to use this together with the form option helpers to create a select where the user can choose multiple records:
<%= form_for(#delivery) do |form| %>
<div class="field">
<%= f.label :item_ids, 'Select the items' %>
<%= f.collection_select :item_ids, #items, :id, :name, multiple: true %>
</div>
<% end %>
Or if you prefer checkboxes:
<%= form_for(#delivery) do |form| %>
<div class="field">
<%= f.label :item_ids, 'Select the items' %>
<%= f.collection_check_boxes :item_ids, #items, :id, :name %>
</div>
<% end %>
Replace :name with whatever attribute you want to use for the option text.
class DeliveriesController < ApplicationController
before_action :set_delivery, only: [:show, :edit, :update, :destroy]
# This avoids a database query in the view
before_action :set_items, only: [:new, :edit]
# POST /deliveries
def create
#delivery = Delivery.new(delivery_params)
if #delivery.save
redirect_to #delivery, notice: 'Delivery created'
else
set_items
render :new
end
end
# PUT|PATCH /deliveries/1
def update
if #delivery.update(delivery_params)
redirect_to #delivery, notice: 'Delivery updated'
else
set_items
render :edit
end
end
private
def set_delivery
#delivery = Delivery.find(params[:id])
end
def set_items
#items = Item.all
end
def delivery_item_params
# Passing the hash `item_ids: []` allows an array of permitted scalar types.
params.require(:delivery)
.permit(:foo, :bar, :baz, item_ids: [])
end
end