在 Rails 表单输入字段中覆盖迁移默认值

Question

I am having a products table with default min_quantity is 0 and max_quantity is MAX INT number 999999999 . When I tried to display this form, the default values from backened are displayed in the UI with min_quantity as 0 and max_quantity as 999999999. How to leave this input fields as blank for the create action?

schema.rb:

create_table "products”, id: :integer, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin", force: :cascade do |t|
  t.string "name", null: false
  t.integer "min_quantity”, default: 0, null: false
  t.integer "max_quantity”, default: 999999999, null: false
end

products/_form.slim:

= simple_form_for([@product]) do |f|
  = f.error_notification
  .form-inputs
    = f.input :name
    = f.input :min_quantity, label: 'Minimum Quantity'
    = f.input :max_quantity, label: 'Maximum Quantity'

I tried using value: nil as:

-if f.object.new_record?
 = f.input :min_quantity, label: 'Minimum Quantity’, input_html: {value: nil}
-else 
= f.input :min_quantity, label: 'Minimum Quantity'

But when there is validation error, the values entered are getting disappeared. The same issue when I use jQuery.

So how can I handle this issue of overriding blackened values in Rails? Please help

Answer 1

You can get the behavior you want by setting the min_quantity and max_quantity to nil in the new method of the controller.

def new
  @product.min_quantity = @product.max_quantity = nil
end

The reason why the values of min_quantity and max_quantity are show when the validation fails is because they are set in the @product object so they actual values of the attributes are going to be shown when the form is reloaded