From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2012-09-25T05:05:19+09:00
Subject: Re: still learning by doing - connecting rooms in a game

On Mon, Sep 24, 2012 at 8:46 PM, Sebastjan H. <lists@ruby-forum.com> wrote:
> Thank you all for recommending the reading and all the suggestions and
> advices. According to those I'll try to re-factor the game like so:
>
> 1. Have one class for Room and then have subclasses for specific rooms.
> 2. Make a map of the rooms in one of the forms suggested above.
>
> I still have difficulties imagining hot to resolve the interaction
> between certain objects.
>
> For example, I wanted to have the kitchen and the dinning room play out
> like so:
>
>         a) room description
>         b) have the player decide whether or not they take some stuff
>         c) second description, prologue to fight
>         d) fight with a zombie
>         e) exit the room

It looks that there is a common algorithm for handling all rooms, so
this algorithm should be implemented only once, maybe in a parent
class of all rooms. It can delegate to the actual implementation of a
room the things related to data: does this room have items to pick?,
the descriptions, the monster and the connections to other rooms. Then
you run this algorithm from a specific room against the player that
enters the room. An example:

class Room

def player_enter player
  puts first_description
  if has_items? #maybe you could check the return of items instead of
having this method
    puts "This is what you can find in the room: #{items}"
    # perform the logic for the player to choose or not to pick
  end
  puts second_description
  if has_monster?
    fight player, monster
  end

  puts "Choose a door:"
  connections.each {|c| print the connection }
  ..
end

And then a specific room just implements the required methods:

class DiningRoom < Room
  def first_description
    "a typical dining room"
  end
  def has_items?
    true
  end
  def items
    [:gun, :bullets]
  end
  def second_description
    "you hear a strange sound coming from the dark corner"
  end
  def has_monster?
    true
  end
  def monster
    Zombie.new :hp => 100, :power => 5 #or however you instantiate zombies
  end
end

BTW, this pattern is called Template Method:
http://en.wikipedia.org/wiki/Template_method_pattern

> If I have all this in the room.state() I can't reference the player
> object since I get the undefined local variable or method for player.

I think the method that runs the algorithm could receive the player as
an argument.

> So I assume I should put any decision making or fighting in the "runner"
> file since the runner knows about all the objects and have the
> room.state contain only the description?

Well, the algorithm to go through a room can very well be in other
object other than a parent of all rooms, but still the above applies:
implement in each room the specifics of the room, putting the
algorithm in a single place.

> If there is another way I can reference these objects? If I initialize
> an object like player in the room itself it is again limited to the room
> in question, right?

I don't think the Room is the right place to initialize the player
object. The player object probably belongs to a Game object or such.
What you can do is pass the appropiate objects where they need to be
used.

Jesus.