Module:Check isxn - Diff

--[[

--[[

This code is derived from the ISXN validation code at Module:Citation/CS1.  It allows validating ISBN,

This code is derived from the ISXN validation code at Module:Citation/CS1.  It allows validating ISBN,

ISMN, and ISSN without invoking a citation template.

ISMN, and ISSN without invoking a citation template.

]]

]]

local p = {}

local p = {}

--[[--------------------------< E R R _ M S G _ S U P L _ T >--------------------------------------------------

--[[--------------------------< E R R _ M S G _ S U P L _ T >--------------------------------------------------

error message supplements for check_isbn(); adapted from a similarly named table at Module:Citation/CS1/Configuration

error message supplements for check_isbn(); adapted from a similarly named table at Module:Citation/CS1/Configuration

]]

]]

local err_msg_supl_t = {

local err_msg_supl_t = {

	['char'] = 'invalid character',

	['char'] = 'invalid character',

	['check'] = 'checksum',

	['check'] = 'checksum',

	['form'] = 'invalid form',

	['form'] = 'invalid form',

	['group'] = 'invalid group id',

	['group'] = 'invalid group id',

	['length'] = 'length',

	['length'] = 'length',

	['prefix'] = 'invalid prefix',

	['prefix'] = 'invalid prefix',

--[[--------------------------< IS _ V A L I D _ I S X N >-----------------------------------------------------

--[[--------------------------< IS _ V A L I D _ I S X N >-----------------------------------------------------

ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in check_isbn().

ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in check_isbn().

If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,

If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,

spaces and other non-isxn characters.

spaces and other non-isxn characters.

]]

]]

local function is_valid_isxn (isxn_str, len)

local function is_valid_isxn (isxn_str, len)

	local temp = 0;

	local temp = 0;

	isxn_str = { isxn_str:byte(1, len) };	-- make a table of byte values '0' → 0x30 .. '9'  → 0x39, 'X' → 0x58

	isxn_str = { isxn_str:byte(1, len) };	-- make a table of byte values '0' → 0x30 .. '9'  → 0x39, 'X' → 0x58

	len = len+1;							-- adjust to be a loop counter

	len = len+1;							-- adjust to be a loop counter

	for i, v in ipairs( isxn_str ) do		-- loop through all of the bytes and calculate the checksum

	for i, v in ipairs( isxn_str ) do		-- loop through all of the bytes and calculate the checksum

		if v == string.byte( "X" ) then		-- if checkdigit is X (compares the byte value of 'X' which is 0x58)

		if v == string.byte( "X" ) then		-- if checkdigit is X (compares the byte value of 'X' which is 0x58)

			temp = temp + 10*( len - i );	-- it represents 10 decimal

			temp = temp + 10*( len - i );	-- it represents 10 decimal

		else

		else

			temp = temp + tonumber( string.char(v) )*(len-i);

			temp = temp + tonumber( string.char(v) )*(len-i);

end

end

end

end

	return temp % 11 == 0;					-- returns true if calculation result is zero

	return temp % 11 == 0;					-- returns true if calculation result is zero

end

end

--[[--------------------------< IS _ V A L I D _ I S X N  _ 1 3 >----------------------------------------------

--[[--------------------------< IS _ V A L I D _ I S X N  _ 1 3 >----------------------------------------------

ISBN-13 and ISMN validator code calculates checksum across all 13 isbn/ismn digits including the check digit.

ISBN-13 and ISMN validator code calculates checksum across all 13 isbn/ismn digits including the check digit.

If the number is valid, the result will be 0. Before calling this function, isbn-13/ismn must be checked for length

If the number is valid, the result will be 0. Before calling this function, isbn-13/ismn must be checked for length

and stripped of dashes, spaces and other non-isxn-13 characters.

and stripped of dashes, spaces and other non-isxn-13 characters.

]]

]]

local function is_valid_isxn_13 (isxn_str)

local function is_valid_isxn_13 (isxn_str)

	local temp=0;

	local temp=0;

	isxn_str = { isxn_str:byte(1, 13) };										-- make a table of byte values '0' → 0x30 .. '9'  → 0x39

	isxn_str = { isxn_str:byte(1, 13) };										-- make a table of byte values '0' → 0x30 .. '9'  → 0x39

	for i, v in ipairs( isxn_str ) do

	for i, v in ipairs( isxn_str ) do

		temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) );				-- multiply odd index digits by 1, even index digits by 3 and sum; includes check digit

		temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) );				-- multiply odd index digits by 1, even index digits by 3 and sum; includes check digit

end

end

	return temp % 10 == 0;														-- sum modulo 10 is zero when isbn-13/ismn is correct

	return temp % 10 == 0;														-- sum modulo 10 is zero when isbn-13/ismn is correct

end

end

--[[--------------------------< C H E C K _ I S B N >------------------------------------------------------------

--[[--------------------------< C H E C K _ I S B N >------------------------------------------------------------

Determines whether an ISBN string is valid.  Implements an ISBN validity check for {{ISBN}}, {{ISBNT}}, {{SBN}}, and

Determines whether an ISBN string is valid.  Implements an ISBN validity check for {{ISBN}}, {{ISBNT}}, {{SBN}}, and

{{Format ISBN}}.

{{Format ISBN}}.

]]

]]

local function check_isbn (isbn_str, frame)

local function check_isbn (isbn_str, frame)

	local function return_result (check, err_type)								-- local function to render the various error returns

	local function return_result (check, err_type)								-- local function to render the various error returns

		if not check then														-- <check> false when there is an error

		if not check then														-- <check> false when there is an error

			local template = ((frame.args.template_name and '' ~= frame.args.template_name) and frame.args.template_name) or nil;	-- get template name

			local template = ((frame.args.template_name and '' ~= frame.args.template_name) and frame.args.template_name) or nil;	-- get template name

			if not template then

			if not template then

				return '<span class="error" style="font-size:100%">&nbsp;calling template requires template_name parameter</span>';

				return '<span class="error" style="font-size:100%">&nbsp;calling template requires template_name parameter</span>';

end

end

			local out_t = {'<span class="error" style="font-size:100%">'};		-- open the error message span

			local out_t = {'<span class="error" style="font-size:100%">'};		-- open the error message span

			table.insert (out_t, '&nbsp;Parameter error in {{[[Template:');		-- open 'template' markup; open wikilink with Template namespace

			table.insert (out_t, '&nbsp;Parameter error in {{[[Template:');		-- open 'template' markup; open wikilink with Template namespace

			table.insert (out_t, template);										-- template name wikilink

			table.insert (out_t, template);										-- template name wikilink

			table.insert (out_t, '|');											-- its pipe

			table.insert (out_t, '|');											-- its pipe

			table.insert (out_t, template);										-- wikilink label

			table.insert (out_t, template);										-- wikilink label

			table.insert (out_t, ']]}}:&nbsp;');								-- close wikilink; close 'template' markup

			table.insert (out_t, ']]}}:&nbsp;');								-- close wikilink; close 'template' markup

			table.insert (out_t, err_type);										-- type of isbn error

			table.insert (out_t, err_type);										-- type of isbn error

			table.insert (out_t, '</span>')										-- close the error message span

			table.insert (out_t, '</span>')										-- close the error message span

			if 0 == mw.title.getCurrentTitle().namespace then					-- categorize only when this template is used in mainspace

			if 0 == mw.title.getCurrentTitle().namespace then					-- categorize only when this template is used in mainspace

				local category = table.concat ({'[[Category:Pages with ISBN errors]]'});

				local category = table.concat ({'[[Category:Pages with ISBN errors]]'});

				table.insert (out_t, category);

				table.insert (out_t, category);

end

end

			return table.concat (out_t);										-- make a big string and done

			return table.concat (out_t);										-- make a big string and done

end

end

	return '';																	-- no error, return an empty string

	return '';																	-- no error, return an empty string

end

end

	if nil ~= isbn_str:match ('[^%s-0-9X]') then

	if nil ~= isbn_str:match ('[^%s-0-9X]') then

		return return_result (false, err_msg_supl_t.char);						-- fail if isbn_str contains anything but digits, hyphens, or the uppercase X

		return return_result (false, err_msg_supl_t.char);						-- fail if isbn_str contains anything but digits, hyphens, or the uppercase X

end

end

	local id = isbn_str:gsub ('[%s-]', '');										-- remove hyphens and whitespace

	local id = isbn_str:gsub ('[%s-]', '');										-- remove hyphens and whitespace

	local len = id:len();

	local len = id:len();

	if len ~= 10 and len ~= 13 then

	if len ~= 10 and len ~= 13 then

		return return_result (false, err_msg_supl_t.length);					-- fail if incorrect length

		return return_result (false, err_msg_supl_t.length);					-- fail if incorrect length

end

end

	if len == 10 then

	if len == 10 then

		if id:match ('^%d*X?$') == nil then										-- fail if isbn_str has 'X' anywhere but last position

		if id:match ('^%d*X?$') == nil then										-- fail if isbn_str has 'X' anywhere but last position

			return return_result (false, err_msg_supl_t.form);

			return return_result (false, err_msg_supl_t.form);

end

end

		if id:find ('^63[01]') then												-- 630xxxxxxx and 631xxxxxxx are (apparently) not valid isbn group ids but are used by amazon as numeric identifiers (asin)

		if id:find ('^63[01]') then												-- 630xxxxxxx and 631xxxxxxx are (apparently) not valid isbn group ids but are used by amazon as numeric identifiers (asin)

			return return_result (false, err_msg_supl_t.group);					-- fail if isbn-10 begins with 630/1

			return return_result (false, err_msg_supl_t.group);					-- fail if isbn-10 begins with 630/1

end

end

		return return_result (is_valid_isxn (id, 10), err_msg_supl_t.check);	-- pass if isbn-10 is numerically valid (checksum)

		return return_result (is_valid_isxn (id, 10), err_msg_supl_t.check);	-- pass if isbn-10 is numerically valid (checksum)

	else

	else

		if id:match ('^%d+$') == nil then

		if id:match ('^%d+$') == nil then

			return return_result (false, err_msg_supl_t.char);					-- fail if ISBN-13 is not all digits

			return return_result (false, err_msg_supl_t.char);					-- fail if ISBN-13 is not all digits

end

end

		if id:match ('^97[89]%d*$') == nil then

		if id:match ('^97[89]%d*$') == nil then

			return return_result (false, err_msg_supl_t.prefix);				-- fail when ISBN-13 does not begin with 978 or 979

			return return_result (false, err_msg_supl_t.prefix);				-- fail when ISBN-13 does not begin with 978 or 979

end

end

		if id:match ('^9790') then

		if id:match ('^9790') then

			return return_result (false, err_msg_supl_t.group);					-- group identifier '0' is reserved to ISMN

			return return_result (false, err_msg_supl_t.group);					-- group identifier '0' is reserved to ISMN

end

end

		return return_result (is_valid_isxn_13 (id), err_msg_supl_t.check);		-- pass if isbn-10 is numerically valid (checksum)

		return return_result (is_valid_isxn_13 (id), err_msg_supl_t.check);		-- pass if isbn-10 is numerically valid (checksum)

end

end

end

end

--[[--------------------------< C H E C K _ I S M N >------------------------------------------------------------

--[[--------------------------< C H E C K _ I S M N >------------------------------------------------------------

Determines whether an ISMN string is valid.  Similar to isbn-13, ismn is 13 digits begining 979-0-... and uses the

Determines whether an ISMN string is valid.  Similar to isbn-13, ismn is 13 digits begining 979-0-... and uses the

same check digit calculations.  See http://www.ismn-international.org/download/Web_ISMN_Users_Manual_2008-6.pdf

same check digit calculations.  See http://www.ismn-international.org/download/Web_ISMN_Users_Manual_2008-6.pdf

section 2, pages 9–12.

section 2, pages 9–12.

]]

]]

local function check_ismn (id, error_string)

local function check_ismn (id, error_string)

	local text;

	local text;

	local valid_ismn = true;

	local valid_ismn = true;

	id=id:gsub( "[%s-–]", "" );													-- strip spaces, hyphens, and endashes from the ismn

	id=id:gsub( "[%s-–]", "" );													-- strip spaces, hyphens, and endashes from the ismn

	if 13 ~= id:len() or id:match( "^9790%d*$" ) == nil then					-- ismn must be 13 digits and begin 9790

	if 13 ~= id:len() or id:match( "^9790%d*$" ) == nil then					-- ismn must be 13 digits and begin 9790

		valid_ismn = false;

		valid_ismn = false;

	else

	else

		valid_ismn=is_valid_isxn_13 (id);										-- validate ismn

		valid_ismn=is_valid_isxn_13 (id);										-- validate ismn

end

end

	return valid_ismn and '' or error_string

	return valid_ismn and '' or error_string

end

end

--[[--------------------------< I S S N >----------------------------------------------------------------------

--[[--------------------------< I S S N >----------------------------------------------------------------------

Validate and format an issn.  This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four

Validate and format an issn.  This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four

digits with a space.  When that condition occurred, the resulting link looked like this:

digits with a space.  When that condition occurred, the resulting link looked like this:

	|issn=0819 4327 gives: [http://www.worldcat.org/issn/0819 4327 0819 4327]  -- can't have spaces in an external link

	|issn=0819 4327 gives: [http://www.worldcat.org/issn/0819 4327 0819 4327]  -- can't have spaces in an external link

This code now prevents that by inserting a hyphen at the issn midpoint.  It also validates the issn for length and makes sure that the checkdigit agrees

This code now prevents that by inserting a hyphen at the issn midpoint.  It also validates the issn for length and makes sure that the checkdigit agrees

with the calculated value.  Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check issn

with the calculated value.  Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check issn

error message.

error message.

]]

]]

local function check_issn(id, error_string)

local function check_issn(id, error_string)

	local issn_copy = id;		-- save a copy of unadulterated issn; use this version for display if issn does not validate

	local issn_copy = id;		-- save a copy of unadulterated issn; use this version for display if issn does not validate

	local text;

	local text;

	local valid_issn = true;

	local valid_issn = true;

	if not id:match ('^%d%d%d%d%-%d%d%d[%dX]$') then

	if not id:match ('^%d%d%d%d%-%d%d%d[%dX]$') then

		return error_string;

		return error_string;

end

end

	id=id:gsub( "[%s-–]", "" );									-- strip spaces, hyphens, and endashes from the issn

	id=id:gsub( "[%s-–]", "" );									-- strip spaces, hyphens, and endashes from the issn

	if 8 ~= id:len() or nil == id:match( "^%d*X?$" ) then		-- validate the issn: 8 digits long, containing only 0-9 or X in the last position

	if 8 ~= id:len() or nil == id:match( "^%d*X?$" ) then		-- validate the issn: 8 digits long, containing only 0-9 or X in the last position

		valid_issn=false;										-- wrong length or improper character

		valid_issn=false;										-- wrong length or improper character

	else

	else

		valid_issn=is_valid_isxn(id, 8);						-- validate issn

		valid_issn=is_valid_isxn(id, 8);						-- validate issn

end

end

	return valid_issn and '' or error_string

	return valid_issn and '' or error_string

end

end

------------------------------< E N T R Y   P O I N T S >--------------------------------------------------====

------------------------------< E N T R Y   P O I N T S >--------------------------------------------------====

function p.check_isbn(frame)

function p.check_isbn(frame)

	return check_isbn(frame.args[1] or frame:getParent().args[1], frame)

	return check_isbn(frame.args[1] or frame:getParent().args[1], frame)

end

end

function p.check_ismn(frame)

function p.check_ismn(frame)

	return check_ismn(frame.args[1] or frame:getParent().args[1], frame.args['error'] or frame:getParent().args['error'] or 'error')

	return check_ismn(frame.args[1] or frame:getParent().args[1], frame.args['error'] or frame:getParent().args['error'] or 'error')

end

end

function p.check_issn(frame)

function p.check_issn(frame)

	return check_issn(frame.args[1] or frame:getParent().args[1], frame.args['error'] or frame:getParent().args['error'] or 'error')

	return check_issn(frame.args[1] or frame:getParent().args[1], frame.args['error'] or frame:getParent().args['error'] or 'error')

end

end

return p

return p

Old	New
--[[	--[[

This code is derived from the ISXN validation code at Module:Citation/CS1. It allows validating ISBN,	This code is derived from the ISXN validation code at Module:Citation/CS1. It allows validating ISBN,
ISMN, and ISSN without invoking a citation template.	ISMN, and ISSN without invoking a citation template.

]]	]]

local p = {}	local p = {}


--[[--------------------------< E R R _ M S G _ S U P L _ T >--------------------------------------------------	--[[--------------------------< E R R _ M S G _ S U P L _ T >--------------------------------------------------

error message supplements for check_isbn(); adapted from a similarly named table at Module:Citation/CS1/Configuration	error message supplements for check_isbn(); adapted from a similarly named table at Module:Citation/CS1/Configuration

]]	]]

local err_msg_supl_t = {	local err_msg_supl_t = {
['char'] = 'invalid character',	['char'] = 'invalid character',
['check'] = 'checksum',	['check'] = 'checksum',
['form'] = 'invalid form',	['form'] = 'invalid form',
['group'] = 'invalid group id',	['group'] = 'invalid group id',
['length'] = 'length',	['length'] = 'length',
['prefix'] = 'invalid prefix',	['prefix'] = 'invalid prefix',
}	}


--[[--------------------------< IS _ V A L I D _ I S X N >-----------------------------------------------------	--[[--------------------------< IS _ V A L I D _ I S X N >-----------------------------------------------------

ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in check_isbn().	ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in check_isbn().
If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,	If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,
spaces and other non-isxn characters.	spaces and other non-isxn characters.

]]	]]

local function is_valid_isxn (isxn_str, len)	local function is_valid_isxn (isxn_str, len)
local temp = 0;	local temp = 0;
isxn_str = { isxn_str:byte(1, len) }; -- make a table of byte values '0' → 0x30 .. '9' → 0x39, 'X' → 0x58	isxn_str = { isxn_str:byte(1, len) }; -- make a table of byte values '0' → 0x30 .. '9' → 0x39, 'X' → 0x58
len = len+1; -- adjust to be a loop counter	len = len+1; -- adjust to be a loop counter
for i, v in ipairs( isxn_str ) do -- loop through all of the bytes and calculate the checksum	for i, v in ipairs( isxn_str ) do -- loop through all of the bytes and calculate the checksum
if v == string.byte( "X" ) then -- if checkdigit is X (compares the byte value of 'X' which is 0x58)	if v == string.byte( "X" ) then -- if checkdigit is X (compares the byte value of 'X' which is 0x58)
temp = temp + 10*( len - i ); -- it represents 10 decimal	temp = temp + 10*( len - i ); -- it represents 10 decimal
else	else
temp = temp + tonumber( string.char(v) )*(len-i);	temp = temp + tonumber( string.char(v) )*(len-i);
end	end
end	end
return temp % 11 == 0; -- returns true if calculation result is zero	return temp % 11 == 0; -- returns true if calculation result is zero
end	end


--[[--------------------------< IS _ V A L I D _ I S X N _ 1 3 >----------------------------------------------	--[[--------------------------< IS _ V A L I D _ I S X N _ 1 3 >----------------------------------------------

ISBN-13 and ISMN validator code calculates checksum across all 13 isbn/ismn digits including the check digit.	ISBN-13 and ISMN validator code calculates checksum across all 13 isbn/ismn digits including the check digit.
If the number is valid, the result will be 0. Before calling this function, isbn-13/ismn must be checked for length	If the number is valid, the result will be 0. Before calling this function, isbn-13/ismn must be checked for length
and stripped of dashes, spaces and other non-isxn-13 characters.	and stripped of dashes, spaces and other non-isxn-13 characters.

]]	]]

local function is_valid_isxn_13 (isxn_str)	local function is_valid_isxn_13 (isxn_str)
local temp=0;	local temp=0;

isxn_str = { isxn_str:byte(1, 13) }; -- make a table of byte values '0' → 0x30 .. '9' → 0x39	isxn_str = { isxn_str:byte(1, 13) }; -- make a table of byte values '0' → 0x30 .. '9' → 0x39
for i, v in ipairs( isxn_str ) do	for i, v in ipairs( isxn_str ) do
temp = temp + (3 - 2(i % 2)) tonumber( string.char(v) ); -- multiply odd index digits by 1, even index digits by 3 and sum; includes check digit	temp = temp + (3 - 2(i % 2)) tonumber( string.char(v) ); -- multiply odd index digits by 1, even index digits by 3 and sum; includes check digit
end	end
return temp % 10 == 0; -- sum modulo 10 is zero when isbn-13/ismn is correct	return temp % 10 == 0; -- sum modulo 10 is zero when isbn-13/ismn is correct
end	end


--[[--------------------------< C H E C K _ I S B N >------------------------------------------------------------	--[[--------------------------< C H E C K _ I S B N >------------------------------------------------------------

Determines whether an ISBN string is valid. Implements an ISBN validity check for {{ISBN}}, {{ISBNT}}, {{SBN}}, and	Determines whether an ISBN string is valid. Implements an ISBN validity check for {{ISBN}}, {{ISBNT}}, {{SBN}}, and
{{Format ISBN}}.	{{Format ISBN}}.

]]	]]

local function check_isbn (isbn_str, frame)	local function check_isbn (isbn_str, frame)
local function return_result (check, err_type) -- local function to render the various error returns	local function return_result (check, err_type) -- local function to render the various error returns
if not check then -- <check> false when there is an error	if not check then -- <check> false when there is an error
local template = ((frame.args.template_name and '' ~= frame.args.template_name) and frame.args.template_name) or nil; -- get template name	local template = ((frame.args.template_name and '' ~= frame.args.template_name) and frame.args.template_name) or nil; -- get template name
if not template then	if not template then
return '<span class="error" style="font-size:100%"> calling template requires template_name parameter</span>';	return '<span class="error" style="font-size:100%"> calling template requires template_name parameter</span>';
end	end

local out_t = {'<span class="error" style="font-size:100%">'}; -- open the error message span	local out_t = {'<span class="error" style="font-size:100%">'}; -- open the error message span
table.insert (out_t, ' Parameter error in {{[[Template:'); -- open 'template' markup; open wikilink with Template namespace	table.insert (out_t, ' Parameter error in {{[[Template:'); -- open 'template' markup; open wikilink with Template namespace
table.insert (out_t, template); -- template name wikilink	table.insert (out_t, template); -- template name wikilink
table.insert (out_t, '\|'); -- its pipe	table.insert (out_t, '\|'); -- its pipe
table.insert (out_t, template); -- wikilink label	table.insert (out_t, template); -- wikilink label
table.insert (out_t, ']]}}: '); -- close wikilink; close 'template' markup	table.insert (out_t, ']]}}: '); -- close wikilink; close 'template' markup
table.insert (out_t, err_type); -- type of isbn error	table.insert (out_t, err_type); -- type of isbn error
table.insert (out_t, '</span>') -- close the error message span	table.insert (out_t, '</span>') -- close the error message span
if 0 == mw.title.getCurrentTitle().namespace then -- categorize only when this template is used in mainspace	if 0 == mw.title.getCurrentTitle().namespace then -- categorize only when this template is used in mainspace
local category = table.concat ({'[[Category:Pages with ISBN errors]]'});	local category = table.concat ({'[[Category:Pages with ISBN errors]]'});
table.insert (out_t, category);	table.insert (out_t, category);
end	end
return table.concat (out_t); -- make a big string and done	return table.concat (out_t); -- make a big string and done
end	end
return ''; -- no error, return an empty string	return ''; -- no error, return an empty string
end	end

if nil ~= isbn_str:match ('[^%s-0-9X]') then	if nil ~= isbn_str:match ('[^%s-0-9X]') then
return return_result (false, err_msg_supl_t.char); -- fail if isbn_str contains anything but digits, hyphens, or the uppercase X	return return_result (false, err_msg_supl_t.char); -- fail if isbn_str contains anything but digits, hyphens, or the uppercase X
end	end

local id = isbn_str:gsub ('[%s-]', ''); -- remove hyphens and whitespace	local id = isbn_str:gsub ('[%s-]', ''); -- remove hyphens and whitespace

local len = id:len();	local len = id:len();

if len ~= 10 and len ~= 13 then	if len ~= 10 and len ~= 13 then
return return_result (false, err_msg_supl_t.length); -- fail if incorrect length	return return_result (false, err_msg_supl_t.length); -- fail if incorrect length
end	end

if len == 10 then	if len == 10 then
if id:match ('^%d*X?$') == nil then -- fail if isbn_str has 'X' anywhere but last position	if id:match ('^%d*X?$') == nil then -- fail if isbn_str has 'X' anywhere but last position
return return_result (false, err_msg_supl_t.form);	return return_result (false, err_msg_supl_t.form);
end	end
if id:find ('^63[01]') then -- 630xxxxxxx and 631xxxxxxx are (apparently) not valid isbn group ids but are used by amazon as numeric identifiers (asin)	if id:find ('^63[01]') then -- 630xxxxxxx and 631xxxxxxx are (apparently) not valid isbn group ids but are used by amazon as numeric identifiers (asin)
return return_result (false, err_msg_supl_t.group); -- fail if isbn-10 begins with 630/1	return return_result (false, err_msg_supl_t.group); -- fail if isbn-10 begins with 630/1
end	end
return return_result (is_valid_isxn (id, 10), err_msg_supl_t.check); -- pass if isbn-10 is numerically valid (checksum)	return return_result (is_valid_isxn (id, 10), err_msg_supl_t.check); -- pass if isbn-10 is numerically valid (checksum)
else	else
if id:match ('^%d+$') == nil then	if id:match ('^%d+$') == nil then
return return_result (false, err_msg_supl_t.char); -- fail if ISBN-13 is not all digits	return return_result (false, err_msg_supl_t.char); -- fail if ISBN-13 is not all digits
end	end
if id:match ('^97[89]%d*$') == nil then	if id:match ('^97[89]%d*$') == nil then
return return_result (false, err_msg_supl_t.prefix); -- fail when ISBN-13 does not begin with 978 or 979	return return_result (false, err_msg_supl_t.prefix); -- fail when ISBN-13 does not begin with 978 or 979
end	end
if id:match ('^9790') then	if id:match ('^9790') then
return return_result (false, err_msg_supl_t.group); -- group identifier '0' is reserved to ISMN	return return_result (false, err_msg_supl_t.group); -- group identifier '0' is reserved to ISMN
end	end
return return_result (is_valid_isxn_13 (id), err_msg_supl_t.check); -- pass if isbn-10 is numerically valid (checksum)	return return_result (is_valid_isxn_13 (id), err_msg_supl_t.check); -- pass if isbn-10 is numerically valid (checksum)
end	end
end	end


--[[--------------------------< C H E C K _ I S M N >------------------------------------------------------------	--[[--------------------------< C H E C K _ I S M N >------------------------------------------------------------

Determines whether an ISMN string is valid. Similar to isbn-13, ismn is 13 digits begining 979-0-... and uses the	Determines whether an ISMN string is valid. Similar to isbn-13, ismn is 13 digits begining 979-0-... and uses the
same check digit calculations. See http://www.ismn-international.org/download/Web_ISMN_Users_Manual_2008-6.pdf	same check digit calculations. See http://www.ismn-international.org/download/Web_ISMN_Users_Manual_2008-6.pdf
section 2, pages 9–12.	section 2, pages 9–12.

]]	]]

local function check_ismn (id, error_string)	local function check_ismn (id, error_string)
local text;	local text;
local valid_ismn = true;	local valid_ismn = true;

id=id:gsub( "[%s-–]", "" ); -- strip spaces, hyphens, and endashes from the ismn	id=id:gsub( "[%s-–]", "" ); -- strip spaces, hyphens, and endashes from the ismn

if 13 ~= id:len() or id:match( "^9790%d*$" ) == nil then -- ismn must be 13 digits and begin 9790	if 13 ~= id:len() or id:match( "^9790%d*$" ) == nil then -- ismn must be 13 digits and begin 9790
valid_ismn = false;	valid_ismn = false;
else	else
valid_ismn=is_valid_isxn_13 (id); -- validate ismn	valid_ismn=is_valid_isxn_13 (id); -- validate ismn
end	end

return valid_ismn and '' or error_string	return valid_ismn and '' or error_string
end	end


--[[--------------------------< I S S N >----------------------------------------------------------------------	--[[--------------------------< I S S N >----------------------------------------------------------------------

Validate and format an issn. This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four	Validate and format an issn. This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four
digits with a space. When that condition occurred, the resulting link looked like this:	digits with a space. When that condition occurred, the resulting link looked like this:

\|issn=0819 4327 gives: [http://www.worldcat.org/issn/0819 4327 0819 4327] -- can't have spaces in an external link	\|issn=0819 4327 gives: [http://www.worldcat.org/issn/0819 4327 0819 4327] -- can't have spaces in an external link

This code now prevents that by inserting a hyphen at the issn midpoint. It also validates the issn for length and makes sure that the checkdigit agrees	This code now prevents that by inserting a hyphen at the issn midpoint. It also validates the issn for length and makes sure that the checkdigit agrees
with the calculated value. Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check issn	with the calculated value. Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check issn
error message.	error message.

]]	]]

local function check_issn(id, error_string)	local function check_issn(id, error_string)
local issn_copy = id; -- save a copy of unadulterated issn; use this version for display if issn does not validate	local issn_copy = id; -- save a copy of unadulterated issn; use this version for display if issn does not validate
local text;	local text;
local valid_issn = true;	local valid_issn = true;

if not id:match ('^%d%d%d%d%-%d%d%d[%dX]$') then	if not id:match ('^%d%d%d%d%-%d%d%d[%dX]$') then
return error_string;	return error_string;
end	end

id=id:gsub( "[%s-–]", "" ); -- strip spaces, hyphens, and endashes from the issn	id=id:gsub( "[%s-–]", "" ); -- strip spaces, hyphens, and endashes from the issn

if 8 ~= id:len() or nil == id:match( "^%d*X?$" ) then -- validate the issn: 8 digits long, containing only 0-9 or X in the last position	if 8 ~= id:len() or nil == id:match( "^%d*X?$" ) then -- validate the issn: 8 digits long, containing only 0-9 or X in the last position
valid_issn=false; -- wrong length or improper character	valid_issn=false; -- wrong length or improper character
else	else
valid_issn=is_valid_isxn(id, 8); -- validate issn	valid_issn=is_valid_isxn(id, 8); -- validate issn
end	end

return valid_issn and '' or error_string	return valid_issn and '' or error_string
end	end


------------------------------< E N T R Y P O I N T S >--------------------------------------------------====	------------------------------< E N T R Y P O I N T S >--------------------------------------------------====

function p.check_isbn(frame)	function p.check_isbn(frame)
return check_isbn(frame.args[1] or frame:getParent().args[1], frame)	return check_isbn(frame.args[1] or frame:getParent().args[1], frame)
end	end

function p.check_ismn(frame)	function p.check_ismn(frame)
return check_ismn(frame.args[1] or frame:getParent().args[1], frame.args['error'] or frame:getParent().args['error'] or 'error')	return check_ismn(frame.args[1] or frame:getParent().args[1], frame.args['error'] or frame:getParent().args['error'] or 'error')
end	end

function p.check_issn(frame)	function p.check_issn(frame)
return check_issn(frame.args[1] or frame:getParent().args[1], frame.args['error'] or frame:getParent().args['error'] or 'error')	return check_issn(frame.args[1] or frame:getParent().args[1], frame.args['error'] or frame:getParent().args['error'] or 'error')
end	end

return p	return p

Diff: Module:Check isxn