model Movement
  def to_param
    name.gsub(/ /, '-')
  end

  def self.find_by_param input
    find_by_name input.gsub(/-/, ' ')
  end
end

model Event
  def to_param
    name.gsub(/ /, '-')
  end

  def self.find_by_param input
    find_by_name input.gsub(/-/, ' ')
  end
end

# It can be solved by using module and submodule
module ParamToName
  module ClassMethods
    def self.find_by_param input
      find_by_name input.gsub(/-/, ' ')
    end
  end

  def to_param
    name.gsub(/ /, '-')
  end

  def self.included(klass)
    klass.extend ClassMethods
  end
end

model Event
  include ParamToName
end

model Movement
  include ParamToName
end

Event.new.to_param
Event.find_by_param input