I am trying to create a Single Table Inheritance.

However, the Controller must be able to know which class to find or create. These are based on another class.

For example, ContactEvent with type = Letter needs to grab attributes from a corresponding Model called Letter.

Here's what I've tried to do and hit a snag, labelled below.

I need to be able to dynamically call assign a value of EventClass so that it can be Letter.find(:conditions =>) or Calls.find(:conditions =>) depending on which type the controller is acting on.

  def new
    @contact_event = ContactEvent.new
    @contact_event.type = params[:event_type] # can be letter, call, postcard, email
    @contact_event.event_id = params[:event_id] # that ID to the corresponding Model
    @contact_event.contact_id = params[:contact]

    @EventClass = case
      when @contact_event.type == 'letter' then 'Letter'
      when @contact_event.type == 'call' then 'Call'
      when @contact_event.type == 'email' then 'Email'

SNAG BELOW:

    @event = @EventClass.find(@contact_letter.letter_id) #how do I make @EventClass actually the Class?SNAG

    # substitution of variables into the body of the contact_event
    @event.body.gsub!("{FirstName}", @contact.first_name)
    @event.body.gsub!("{Company}", @contact.company_name) 
    @evebt.body.gsub!("{Colleagues}", @colleagues.to_sentence)

    @contact_event.body = @event.body
    @contact_event.status = "sent"

  end