passing html input from view to controller in rails

Question

My repo: https://github.com/Gtar69/artstore_hw2 => It's my shopping cart project

Now I want to input a value in the carts/index.html to change cart_item quantity.

No idea how to do that in rails

In typical php it's like

<form action="backend.php"> 
  <td><input type="number" name= "kobe"> 
    <input type="submit" value="submit/>
  </td>

However, I want simplify the coding structure instead of using form.

My idea is => view/carts/index.html

<tbody>
  <% current_cart.items.each do |product| %>
    <tr>
      <td><%= render_product_photo(product.default_photo) %></td>

      <td> 
        <%= link_to(product.title, admin_product_path(product)) %>
      </td>

      <td><%= product.price %></td>

      <td>
         <input type="number" name= "kobe" value = <%= CartItem.where(product_id: product.id).take!.count%>>
         <input type="submit" value="shala">
      </td>

      <td><%= link_to("改變數量", change_item_quantity_carts_path(:product_id => product.id, :count => 2),
                      :method => :post , :class => "btn btn-primary btn-lg btn-danger") %></td>

      <td><%= link_to("刪除物品", delete_item_carts_path(:product_id => product.id) , :method => :post, :class => "btn btn-primary btn-lg btn-danger") %></td>
    </tr>
  <% end %>
</tbody>

passing "kobe" variable to carts_controller

def change_item_quantity
  product = Product.find(params[:product_id])
  # :count => 2  
  current_cart.change_cart_item_quantity(product ,params[:kobe])
  redirect_to carts_path
end   

and do backend calculation in model/cart.rb

def change_cart_item_quantity(product, count)
  #改變cart_item中的數量
  c= CartItem.where(product_id: product.id).take!
  c.count = count
  c.save
end  

I'm still struggling in how to pass "kobe" to controller. Any ideas?

Thanks in advance.

Answer 1

refer to guides.rubyonrails.org/form_helpers.html

I used

<td>
              <%= form_tag("/carts/change_item_quantity", method: "post") do%>
                <%= label_tag(:q, "改變數量") %>
                <%= number_field_tag(:kobe, CartItem.where(product_id: product.id).take!.count)%>
                <%= hidden_field_tag(:product_id, product.id)%>
                <%= submit_tag("Change") %>
                <% end %>
            </td>

In that way, I can pass any parameter I needed to controller.