-- this module is created to support {{London Gazette}}  require('Module:No globals') local getArgs = require('Module:Arguments').getArgs  local span_open = '<span style="font-size:100%; font-weight:normal" class="error">'; local code_open = '<code style="color:inherit; border:inherit; padding:inherit;">'; local help_link = ' ([[Template:London Gazette#Error messages|help]])';  local supp_error = mw.ustring.format ('%sinvalid %s&#124;supp=</code>%s</span>', span_open, code_open, help_link); local duplicate_page_error = mw.ustring.format (' %smore than one of %s&#124;page=</code> and %s&#124;pages=</code>%s</span>', span_open, code_open, code_open, help_link);  local p = {}   --[[--------------------------< I S _ S E T >------------------------------------------------------------------  Whether variable is set or not. A variable is set when it is not nil and not empty.  ]]  local function is_set( var )  return not (var == nil or var == ''); end   --[[--------------------------< O R D I N A L _ S U F F I X >--------------------------------------------------  render a numerical text string in ordinal form suitable for English language use. In this module, num_str is limited by calling functions to the integer values 1-99. The argument num_str must be known to be set before this function is called.  ]]  local function ordinal_suffix (num_str)  local lsd; -- least significant digit  local suffixes = {['1'] = 'st', ['2'] = 'nd', ['3'] = 'rd'}; -- table of suffixes except 'th'   if num_str:match ('^1[1-3]$') then -- check the 11-13 odd balls first to get them out of the way  return num_str .. 'th'; -- 11th, 12th, 13th  end   lsd = num_str:match ('^%d?(%d)$'); -- all other numbers: get the least significant digit  return num_str .. (suffixes[lsd] or 'th'); -- append the suffix from the suffixes table or default to 'th' end   --[[--------------------------< M A K E _ P A G E _ P A R A M >------------------------------------------------  Determine the value to be assigned to the specified cs1|2 |page= or |pages= parameter in {{London Gazette}}. The arguments |param=page and |param=pages specify which of the cs1|2 parameters |page= or |pages= for which this function is to create a value.  This function inspects the content of the |page= and |pages= parameters, along with the |param= specifier. From this information it creates a value appropriate for the specified |page= or |pages= parameter. Only one will have a value, the other will get an empty string.  This function is called twice from {{London Gazette}}; once for each of cs1 |page= and |pages= parameters:  |page={{#invoke:Gazette util|make_page_param|param=page|page={{{page|}}}|pages={{{pages|}}}}}  |pages={{#invoke:Gazette util|make_page_param|param=pages|page={{{page|}}}|pages={{{pages|}}}}}  except for the lvalue and the rvalue assigned to |param=, the two calls must be identical else odd results.  |page= or |pages= without a comma, hyphen, or en dash separator → cs1 |page= |page= or |pages= with a separator → cs1 |pages=  Hyphen separator characters are converted to en dash characters. Any white space around hyphen and en dash separators is removed.  If both |page= and |pages= are set, this function mimics cs1|2 and chooses |page=.  Another function, page_error() is required for error messaging because we don't want to dump css markup into a parameter value that will be included in the cs1|2 metadata.  ]]  function p.make_page_param (frame)  local args = getArgs(frame);  local page_or_pages;   page_or_pages = args.page or args.unnamed or args.pages; -- only one; prefer |page=   if is_set (page_or_pages) then  if 'pages' == args.param then  if page_or_pages:match ('[,%-–]') then -- only for |pages= parameter  page_or_pages = mw.ustring.gsub (page_or_pages, '%s*[%-–]%s*', '–'); -- hyphen to en dash; remove spaces  return page_or_pages; -- has separator character so make the parameter |pages=  else  return ''; -- no separator so value will be assigned to |page=  end  elseif 'page' == args.param then  if page_or_pages:match ('[,%-–]') then -- only for |pages= parameter  return ''; -- has separator so value will be assigned to |pages=  else  return page_or_pages; -- no separator character so make the parameter |page=  end  else  return ''; -- |param= something else  end  end   return ''; -- if here no pagination or not correct |page= or |pages= parameter end   --[[--------------------------< P A G E _ E R R O R >----------------------------------------------------------  Inspect page number parameters and return an error message that will be appended to the end of the {{cite magazine}} template rendering. Error messages are handled this way so that the error message is not made part of the cs1|2 citation's metadata.  {{#invoke:Gazette util|page_error|page={{{page|}}}|pages={{{pages|}}}}}  ]]  function p.page_error (frame)  local args = getArgs(frame);   if is_set (args.page) and is_set (args.pages) then  return duplicate_page_error; -- both of |page= and |pages= are set  else  return '';  end end   --[[--------------------------< T Y P E _ P A R A M >----------------------------------------------------------  set the value that is assigned to the cite magazine |type= parameter using the values of the London Gazette |supp= and |display-supp= parameters  Only limited |supp= values will set the type value. These are: 'y' or a number 1-99.  row numbers in comments apply to the table in Template_talk:London_Gazette#Rewrite_as_wrapper_around_template:cite_news  ]]  function p.type_param (frame)  local args = getArgs(frame);   if not is_set (args['display-supp']) and not is_set (args.supp) then -- when both |display-supp= and |supp= are not set  return ''; -- [row 1] not a supplement so no display  end   args.supp = args.supp and args.supp:lower(); -- make text values lower case   if not is_set (args['display-supp']) and is_set (args.supp) then -- when only |supp= is set  if 'y' == args.supp then  return 'Supplement'; -- [row 2] the first or only supplement  elseif args.supp:match ('^%d%d?$') then -- one or two digits  return ordinal_suffix (args.supp) .. ' supplement'; -- [row 3] for the 1st-99th supplement  else  return supp_error; -- [row 4] any other text not supported show an error message  end  end   if is_set (args['display-supp']) and not is_set (args.supp) then -- when only |display-supp= is set  if args['display-supp']:match ('^%d%d?$') then -- one or two digits  return ordinal_suffix (args['display-supp']) .. ' supplement'; -- [row 7] for the 1st-99th supplement  elseif 'y' == args['display-supp'] then  return 'Supplement'; -- [row 6] unnumbered supplement in /page/ space  else  return args['display-supp']; -- [row 11] user specified text; supplement is not in supplement space (a Gazette website error)  end  end  -- here when both |display-supp= and |supp= are set  if args['display-supp']:match ('^%d%d?$') then -- supplement number  if 'y' == args.supp or (args['display-supp'] == args.supp) then  return ordinal_suffix (args['display-supp']) .. ' supplement'; -- [rows 8, 9]  else -- |supp= is not a number or number isn't same as number in |display-supp=  return supp_error; -- [row 10] different values are ambiguous  end  else -- not a supplement number  if ('y' == args.supp) and ('none' == args['display-supp']) then  return ''; -- [row 5] for the case when a /page/ is in /supplement/ space   elseif ('y' == args.supp) or args.supp:match ('^%d%d?$') or not is_set (args.supp) then  return args['display-supp']; -- [rows 12, 13] user specified text  else  return supp_error; -- [row 14] any other |supp= value not supported show an error message  end  end end   --[[--------------------------< U R L _ C I T Y >--------------------------------------------------------------  sets the city element of the url path according to |city= value; defaults to London  ]]  local function url_city (city_param)  local city_names = {['b'] = 'Belfast', ['belfast'] = 'Belfast', ['e'] = 'Edinburgh', ['edinburgh'] = 'Edinburgh'};   city_param = city_param and city_param:lower(); -- lower() to index into the city_names table   return city_names[city_param] or 'London'; -- the city, or default to London end   --[[--------------------------< U R L _ P A G E >--------------------------------------------------------------  sets the page number element of the url path according to |page= or |pages=, and the value assigned to |supp= parameter. This function assumes that supplements may have page numbering that are digits prefixed with one or two letters: B1, B41, RH2, etc; also assumes that regular issues have digit-only page numbers.  Only limited |supp= values will set the page number path element. These are: 'y' or a number 1-99.  ]]  local function url_page (page, supp)  if is_set (supp) then  if ('y' == supp) or supp:match ('^%d%d?$') then  page = page:match ('^%a?%a?%d+'); -- one or two letters followed by digits or just digits (supplement to issue 61608)  else  page = page:match ('^%d+'); -- |supp= set to an unexpected value, so one or more digits only  end  else  page = page:match ('^%d+'); -- |supp= not set, so one or more digits only  end   return page or ''; -- at minimum return empty string for concatenation end   --[[--------------------------< U R L _ P A G E _ O R _ S U P P L E M E N T >----------------------------------  sets the page/supplement element of the url path according to |supp= value; defaults to page  Only limited |supp= values will set the page/supplement path element to /supplement/. These are: 'y' or a number 1-99  ]]  local function url_page_or_supplement (supp_param)  supp_param = (supp_param and supp_param:lower()) or ''; --make sure lower case for comparisons   if ('y' == supp_param) or supp_param:match ('^%d%d?$') then  return 'supplement';  else  return 'page'; -- anything else  end end   --[[--------------------------< U R L _ P A R A M >------------------------------------------------------------  Build a url given |city=, |issue=, |supp=, and one of |page= or |pages=; result is assigned to |url=  |url={{#invoke:Gazette util|url_param|city={{{city|}}}|issue={{{issue}}}|supp={{{supp|}}}|page={{{page|}}}|pages={{{pages|}}}}}  ]]  function p.url_param (frame)  local args = getArgs(frame);  local pg = args.page or args.pages or ''; -- first set parameter or empty string   local url_table = { -- a table of the various url parts  'https://www.thegazette.co.uk', -- static domain name  url_city (args.city), -- default to London  'issue', -- static path text  args.issue, -- issue number  url_page_or_supplement (args.supp), -- either of /page/ or /supplement/ according to the state of |supp=  url_page (pg, args.supp) -- pages: digits only; supplements: optional letter followed by 1 or more digits  };   return table.concat (url_table, '/'); -- concatenate all of the parts together and done end   return p;