Rails URL validate

ruby 代码

validates_each :href, :on => :create do |record, attr, value|
  begin
    uri = URI.parse(value)
    if uri.class != URI::HTTP
      record.errors.add(attr, 'Only HTTP protocol addresses can be used')
    end
  rescue URI::InvalidURIError
    record.errors.add(attr, 'The format of the url is not valid.')
  end
end