Modul:ISBN

p = {} p.ISBN = function( frame ) local pframe = frame:getParent() local args = pframe.args local arg1 = args[ 1 ] arg1 = arg1:gsub('x','X') -- change 'x' to 'X' in order to avoid search failure in Special:Bokkällor (or Lua error) local arg = string.gsub(arg1,"%(.*%)","") -- remove possible parenthesis, e.g. "(inb.)", in the parameter value if arg and arg ~= then local link = 'ISBN ' .. arg1 .. '' local copy = arg copy = copy:gsub( '[^0-9X]', ) -- remove everything that is not a digit or X in order to avoid Lua error) − local length = copy:len() if length == 10 then local t = {} for i = 1, length do if copy:sub( i, i ) == 'X' then t[ i ] = 10 else t[ i ] = copy:sub( i, i ) end end local t2 = {} local multiplier = 10 for i = 1, #t do t2[ i ] = t[ i ] * multiplier multiplier = multiplier -1 end local sum = 0 for i = 1, #t2 do sum = sum + t2[ i ] end local remainder = sum % 11 if remainder ~= 0 then return link .. ' ' .. frame:preprocess('Mall:Error') .. end elseif length == 13 then local t = {} for i = 1, length do if copy:sub( i, i ) == 'X' then t[ i ] = 10 -- just to avoid Lua error if someone gives a ISBN-13 containing a 'X' else t[ i ] = copy:sub( i, i ) end end local t2 = {} for i = 1, #t do if i % 2 == 0 then t2[ i ] = t[ i ] * 3 else t2[ i ] = t[ i ] end end local sum = 0 for i = 1, #t2 do sum = sum + t2[ i ] end local remainder = sum % 10 if remainder ~= 0 then return link .. ' ' .. frame:preprocess('Mall:Error') .. end else return link .. ' ' .. frame:preprocess('Mall:Error') .. end return link else return '' end end return p