Class: MailChess::Board

Inherits:
Object
  • Object
show all
Defined in:
lib/mail_chess/board.rb

Overview

Represents a chessboard.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db, board_id) ⇒ Board

Create a new Board object.

Arguments:

db: Sequel database object
board_id: (Integer)



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# File 'lib/mail_chess/board.rb', line 29

def initialize db, board_id
  @db = db

  Board.create_tables(@db) if Board.need_to_create_tables?(@db)

  @db_entry = @db[:boards].filter(:id => board_id).first

  @id = @db_entry[:id].to_i
  @pieces = {}
  @db[:pieces].filter(:board_id => @id).all.each do |p|
    Piece::Piece.load! db, p[:id], self
  end
end

Instance Attribute Details

#board ⇒ Object

Board itself.



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# File 'lib/mail_chess/board.rb', line 19

def board
  @board
end

#id ⇒ Object (readonly)

Board ID in database.



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# File 'lib/mail_chess/board.rb', line 16

def id
  @id
end

#pieces ⇒ Object

Pieces on this board.



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# File 'lib/mail_chess/board.rb', line 22

def pieces
  @pieces
end

Class Method Details

.create_tables(db) ⇒ Object

Create tables.



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# File 'lib/mail_chess/board.rb', line 51

def self.create_tables db
  db.create_table? :boards do
    primary_key :id
  end

  db.create_table? :pieces do
    primary_key :id
    String :type
    String :color
    String :position
    foreign_key :board_id, :boards, :key => :id
  end
end

.load!(db, filter, value) ⇒ Object

Load game from database.

Arguments:

db: Sequel database object
filter: (Symbol) :id only (for now)
value: filters value

Returns: (Board)

Raises:

  • (ArgumentError) 


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# File 'lib/mail_chess/board.rb', line 87

def self.load! db, filter, value
  raise ArgumentError unless [:id, :reference].index(filter)
  dataset = db[:games].filter(filter => value)
  raise ArgumentError unless dataset.all.size == 1

  id = dataset.first[:id]

  b = Board.new db, id

  return b
end

.need_to_create_tables?(db) ⇒ Boolean

Checks if needed to create tables.

Returns: (Boolean)

Returns:

  • (Boolean) 


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# File 'lib/mail_chess/board.rb', line 46

def self.need_to_create_tables? db
  return (db.tables + [:boards, :pieces]).uniq.size != db.tables.size
end

.new!(db) ⇒ Object

Create new board object and save it to database.

Arguments:

db: Sequel database object

Returns: (Board)



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# File 'lib/mail_chess/board.rb', line 71

def self.new! db
  Board.create_tables(db) if Board.need_to_create_tables?(db)

  id = db[:boards].insert

  return Board.new db, id
end

Instance Method Details

#add(field, piece) ⇒ Object

Add a new piece to board.

Arguments:

field: (String)
piece: (Piece)

Returns: (Piece)



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# File 'lib/mail_chess/board.rb', line 122

def add field, piece
  @pieces[field] = piece

  return piece
end

#delete! ⇒ Object

Delete game – save! won’t fix it!



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# File 'lib/mail_chess/board.rb', line 107

def delete!
  pieces.values.each do |p|
    p.delete!
  end
  
  # board deleted in Game class
end

#remove(field) ⇒ Object

Removes a piece from board.

Arguments:

field: (String)

Returns: (Piece)



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# File 'lib/mail_chess/board.rb', line 134

def remove field
  piece = @pieces[field]
  @pieces.delete(field)

  return piece
end

#save! ⇒ Object

Save game – save the pieces.



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# File 'lib/mail_chess/board.rb', line 100

def save!
  pieces.values.each do |p|
    p.save!
  end
end

#start! ⇒ Object

Place the start position of pieces.



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# File 'lib/mail_chess/board.rb', line 142

def start!
  COLS.each do |c|
    Piece::Pawn.new!(@db, self, c + '2', :white)
    Piece::Pawn.new!(@db, self, c + '7', :black)
  end

  %w[a h].each do |c|
    Piece::Rook.new!(@db, self, c + '1', :white)
    Piece::Rook.new!(@db, self, c + '8', :black)
  end

  %w[b g].each do |c|
    Piece::Knight.new!(@db, self, c + '1', :white)
    Piece::Knight.new!(@db, self, c + '8', :black)
  end

  %w[c f].each do |c|
    Piece::Bishop.new!(@db, self, c + '1', :white)
    Piece::Bishop.new!(@db, self, c + '8', :black)
  end

  Piece::Queen.new!(@db, self, 'd1', :white)
  Piece::Queen.new!(@db, self, 'd8', :black)

  Piece::King.new!(@db, self, 'e1', :white)
  Piece::King.new!(@db, self, 'e8', :black)
end

#to_html(player = :white) ⇒ Object

Generate HTML output.

Attributes:

player: (Symbol) which view

Returns: (String)



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# File 'lib/mail_chess/board.rb', line 176

def to_html player = :white
  result = '<table border="0" cellpadding="0" cellspacing="0">'
  result << '<tr height="40"><td align="center" width="40"></td>'

  cols = (player == :white ? COLS : COLS.reverse)
  cols.each do |c|
    result << '<td align="center" width="40"><b>'
    result << c.capitalize + '</b></td>'
  end
  result << '<td align="center" width="40"></td></tr>'

  rows = (player == :white ? ROWS : ROWS.reverse)
  start_color = :white

  rows.each do |r|
    result << '<tr height="40"><td align="center"><b>' + r + '</b></td>'
    cell_color = start_color
    cols.each do |c|
      result << '<td align="center" bgcolor="'
      result << (cell_color == :white ? '#ffffff' : '#d0d0d0')
      result << '">'
      
      if @pieces[c + r]
        result << '<font size="6">'
        result << @pieces[c + r].html
        result << '</font>'
      end
      result << '</td>'
      cell_color = (cell_color == :white ? :black : :white)
    end
    result << '<td align="center"><b>' + r + '</b></td></tr>'
    start_color = (start_color == :white ? :black : :white)
  end

  result << '<tr height="40"><td align="center" width="40"></td>'
  cols.each do |c|
    result << '<td align="center" width="40"><b>'
    result << c.capitalize + '</b></td>'
  end
  result << '<td align="center" width="40"></td></tr>'

  result << '</table>'

  return result
end