Module:Chessboard: Difference between revisions
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m Frietjes moved page Module:Chess from fen to Module:Chessboard without leaving a redirect: expanding this to make it work for more than just FEN |
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Revision as of 15:52, 10 May 2013
This module is subject to page protection. It is a highly visible module in use by a very large number of pages, or is substituted very frequently. Because vandalism or mistakes would affect many pages, and even trivial editing might cause substantial load on the servers, it is protected from editing. |
Usage
Implements {{Chess diagram}}
{{#invoke:Chessboard|function_name}}
function chessboard( fen, size, reverse )
local piecenames = { p = 'Pawn', r = 'Rook', n = 'Knight', b = 'Bishop', q = 'Queen', k = 'King' }
local colornames = { l = 'White', d = 'Black' }
function rowchar( row ) return 9 - row end
function filechar( file ) return ( "abcdefgh" ):sub( file, file ) end
function coord( ind ) return ( reverse and ( 8 - ind ) * size ) or ( ind - 1 ) * size end
function piecediv( piece, row, file, res )
local color = piece:match( '%u' ) and 'l' or 'd'
piece = piece:lower()
local alt = string.format("%s%s %s %s", filechar( file ), rowchar( row ), colornames[color], piecenames[piece] or piece)
local img = string.format('[[File:Chess %s%st45.svg|%dx%dpx|alt=%s|%s]]', piece, color, size, size, alt, alt)
table.insert( res, string.format('<div style="position:absolute;z-index:3;top:%dpx;left:%dpx;">%s</div>', coord( row ), coord( file ), img) )
end
function oneRow( s, row, res )
local file = 1
for piece in s:gmatch( "%w" ) do -- if a digit, increment "file" by the digit. else, add the piece _and_ increment file by 1
file = file + ( piece:match("%d") or piecediv( piece, row, file, res ) or 1 )
end
end
local result = {}
table.insert(result, string.format([=[
<div class="chess-fen" style="position:relative;">
[[File:Chessboard480.png|%dx%dpx|link=]]
]=], size * 8, size * 8))
local row = 0
for srow in string.gmatch("/" .. fen, "/%w+") do
row = row + 1
oneRow(srow, row, result)
end
table.insert(result, '</div>')
return result
end
--[[
this function is to be used only from Template:Chess diagram.
it provides part of the FEN string - the part that describes the board itself.
unfortunately, the template does not carry enough information to create the 2nd
part of the FEN, which includes information about whose turn is it, en-passant state,
castling, etc.
]]
function diagramToFen( frame )
function nullOrWhitespace( s ) return not s or s:match( '^%s*(.-)%s*$' ) == '' end
function piece( s )
return nullOrWhitespace( s ) and 1
or s:gsub( '%s*(%a)(%a)%s*', function( a, b ) return b == 'l' and a:upper() or a end )
end
local args = frame:getParent().args
local res = ''
for row = 0, 7 do
for file = 0, 7 do
res = res .. piece( args[3 + row * 8 + file] )
end
if row < 7 then res = res .. '/' end
end
return ( res.gsub('1+', function( s ) return #s end ) )
end
return {
f = function( frame )
local args = frame.args
local t = chessboard( args.fen, args.size or 30, ( args.reverse or '' ):lower() == "true" )
return table.concat( t, "\n" )
end,
['extract fen'] = diagramToFen,
}