Problem with getting data from html in RoR controller - html

Question

I'm trying to make a product cart.
I want to be able choose the quantity of product when i add the product to cart.
This is LineItemsController
class LineItemsController < ApplicationController
include CurrentCart
before_action :set_line_item, only: [:show, :edit, :update, :destroy]
before_action :set_cart, only: [:create]
def index
#line_items = LineItem.all
end
def show
end
def new
#line_item = LineItem.new
end
def edit
end
def create
product = Product.find(params[:product_id])
#line_item = #cart.add_product(product)
#line_item.quantity = params['q'].to_i
if #line_item.save
redirect_to #line_item.cart, notice: 'Item added to cart.'
else
render :new
end
end
def update
if #line_item.update(line_item_params)
redirect_to #line_item, notice: 'Line item was successfully updated.'
else
render :edit
end
end
def destroy
#cart = Cart.find(session[:cart_id])
#line_item.destroy
redirect_to cart_path(#cart), notice: 'Item successfully removed.'
end
private
def set_line_item
#line_item = LineItem.find(params[:id])
end
def line_item_params
params.require(:line_item).permit(:product_id, :quantity)
end
end
This is view/line_item/_form.html.erb
<%= simple_form_for(#line_item) do |f| %>
<%= f.error_notification %>
<div class="form-inputs">
<%= f.association :product %>
<%= f.association :cart %>
</div>
<div class="form-actions">
<%= f.button :submit %>
</div>
<% end %>
This is view/product/show.html.erb
<% content_for :body_class, 'bg-light' %>
<section class="section instrument-show">
<div class="columns">
<div class="column is-8">
<%= render 'shared/breadcrumb', category: #product.category %>
<h1 class="title is-2"><%= #product.title %></h1>
<!--ul class="pv1">
<%# if #product.brand? %>
<li class="inline-block pr3"><%#= #product.brand %></li-->
<%# end %>
<!--li class="inline-block pr3"><%#= #product.model %></li-->
<%# if #product.condition? %>
<!--li class="inline-block pr3"><%#= #product.condition %></li>
<%# end %>
</ul-->
<div class="feature-image">
<%= image_tag(#product.image_url(:default).to_s) %>
</div>
<div class="content pa4 mt3 bg-white border-radius-3">
<h3 class="subtitle is-4">Description</h3>
<%= #product.description %>
<h3 class="subtitle is-4 pt5">Product Specs</h3>
<table class="table is-narrow">
<% if #product.category.present? %>
<tr>
<td class="has-text-weight-bold">Category:</td>
<td><%= link_to #product.category.name, #product.category %></td>
</tr>
<% end %>
<%# if #product.finish %>
<tr>
<td class="has-text-weight-bold">Finish:</td>
<td><%#= #product.finish %></td>
</tr>
<%# end %>
<tr>
<td class="has-text-weight-bold">Model:</td>
<td><%#= #product.model %></td>
</tr>
</table>
</div>
</div>
<div class="column is-3 is-offset-1">
<div class="bg-white pa4 border-radius-3">
<h4 class="title is-5 has-text-centered"><%= number_to_currency(#product.price) %></h4>
<p class="has-text-centered mb4">Sold by <%#= #product.user.name %></p>
<form>
<input type="number" name="q" min="1" max="50" step="1" class="input label">
</form>
<%= button_to 'Add to cart', line_items_path(product_id: #product), class: 'button is-warning add-to-cart' %>
</div>
</div>
</div>
<% if user_signed_in? && current_user.admin? %>
<%= link_to 'Edit', edit_admin_product_path(#product), class: 'button' %>
<% end %>
</section>
Now in this string #line_item.quantity = params['q'].to_i from
<form>
<input type="number" name="q" min="1" max="50" step="1" class="input label">
</form>
i'm getting "nil" and i desperately don't now what should i do to get actual number.
P.S. This is view/line_items/new.html.erb
<h1>New Line Item</h1>
<%= render 'form', line_item: #line_item %>
<%= link_to 'Back', line_items_path %>

Answer 1

new.html.erb is to enter your data and if you submit, the data will flow to create method inside your controller, meanwhile show is just to show the data, and you cannot input form inside show,
my suggestion try to put q part of new.html.erb, and put it inside simple_form_for tag
since it is number, you can use number_field rails tag helper as sample below, with name :q and range between 1 .. 50 with step 1, below is the sample probably can help your problem
when you submit from new.html.erb, you will receive params[:q] as part of parameters and save it with create method
<%= simple_form_for(#line_item) do |f| %>
<%= f.error_notification %>
<%= number_field(:q, in: 1.0..50.0, step: 1) %>
<div class="form-inputs">
<%= f.association :product %>
<%= f.association :cart %>
</div>
<div class="form-actions">
<%= f.button :submit %>
</div>
<% end %>