Question

How do I make Rails treat the “http://” value as blank: if the value is “http://”, do not validate website field and insert an empty string (not “http://”) into database?

In view:

<%= f.text_field :website, value: "http://" %>

In model:

validates :website, format: { with: /^https?:\/\/\S+/i }, allow_blank: true

Answer 1

You can use :if or :unless to conditionally validate (untested):

validates :website, format: { with: /^https?:\/\/\S+/i }, allow_blank: true, :unless => ['http://', 'https://'].include?(params[:website]) } 

Use a before_save callback to convert the string to blank:

def before_save
  self.website = "" if ['http://', 'https://'].include?(self.website)

  true
end