Rails 5 - Custom validation with one error message

Question

I want to add multiple conditions to valid but i want to view only one summary error message.

validates :floor, presence: true, numericality: { only_integer: true }, length: { maximum: 2 }

How show only one message whenever having any error, like: "Floor is required, must be number..."

In addition, when i use:

if @posts.valid?
   @posts.save
   redirect_to room_path
else
   render :new
end

Browser will render new with message but url is http://localhost:3000/posts , it is not http://localhost:3000/posts/new This is a problem when user refresh page => it will return index page (not new page). How can i fix it?

Answer 1

You can write custom validator:

validate :validate_floor

private
def validate_floor
  return if floor.present? && floor.scan(/\D/).empty? && floor.length <= 2
  errors.add(:floor, 'Floor is required, must be number...')
end

Other question;

When you post the form, the request goes to create action. Because of the create action, the path is redirected to http://localhost:3000/posts . When there is an error in the form, the form is re-rendered with render:new . But the url doesn't change because there is no redirect. Actually, there is no error here. This is what it should be.