Module:Footnotes/anchor id list
require('strict');
 local data = mw.loadData ('Module:Footnotes/anchor id list/data');
 local whitelist = mw.loadData ('Module:Footnotes/whitelist');
 local Lang_obj = mw.language.getContentLanguage();								-- used by template_list_add() to uppercase first letter of template name TODO: better way to do that?
 
 local redirects_date = {
 	['date'] = true,
 	['datetomos'] = true,
 	['formatdate'] = true,
 	['isotodmymdy'] = true,
 	['isotomos'] = true,
 	}
 local redirects_patent = {														-- special case cs1-like templates because uses different parameters for name and date in anchor ID
 	['Cite patent'] = true,
 	['Citeref patent'] = true,
 	['Ref patent'] = true,
 	}
 local redirects_sfnref = {
 	['sfnref'] = true,
 	['harvid'] = true,
 	}
 local aliases_author = {														-- these use pseudo-patterns in the same way as cs1|2; '#' represents 1 or more enumerator digits
 	'last#',
 	'author#',
 	'surname#',
 	'author-last#',
 	'author#-last',
 	'subject#',
 	'host#',
 	}
 local aliases_contributor = {
 	'contributor#',
 	'contributor-last#',
 	'contributor#-last',
 	'contributor-surname#',
 	'contributor#-surname',
 	}
 local aliases_editor = {
 	'editor#',
 	'editor-last#',
 	'editor#-last',
 	'editor-surname#',
 	'editor#-surname',
 	}
 local aliases_harvc_author = {
 	'last#',
 	'author#',
 	}
 local aliases_inventor = {														-- cite patent
 	'inventor#',
 	'inventor-last#',
 	'inventor#-last',
 	'inventor-surname#',
 	'inventor#-surname',
 	'invent#',
 	'invent-#',
 	}
 local alias_patterns_date = {													-- normal lua patterns for most cs1|2-like templates
 	'|%s*year%s*=%s*',
 	'|%s*date%s*=%s*',
 	'|%s*publication%-?date%s*=%s*',
 	'|%s*air%-?date%s*=%s*',
 	}
 local alias_patterns_harvc_date = {												-- normal lua patterns for harvc template
 	'|%s*anchor%-year%s*=%s*',
 	'|%s*year%s*=%s*',
 	}
 local alias_patterns_patent_date = {											-- normal lua patterns for cite patent templates
 	'|%s*issue%-date%s*=%s*',
 	'|%s*gdate%s*=%s*',
 	'|%s*publication%-date%s*=%s*',
 	'|%s*pubdate%s*=%s*',
 	}
 local patterns_date = {															-- normal lua patterns
 	'(%d%d%d%d–%d%d%d%d%l?)$',													-- YYYY–YYYY four-digit year range at end (Season YYYY–YYYY); with or without dab
 	'^(%d%d%d%d–%d%d%l?)$',														-- YYYY–YY two-digit year range; with or without dab
 	'^(c%. %d%d%d%d?%l?)$',														-- three- or four-digit circa year; with or without dab
 	'(%d%d%d%d?%l?)$',															-- three- or four-digit year at end of date (dmy or mdy); with or without dab
 	'^(%d%d%d%d?%l?)',															-- three- or four-digit year at beginning of date (ymd or YYYY); with or without dab
 	'^(n%.d%.%l?)$',															-- 'no date' with dots; with or without dab
 	'^(nd%l?)$',																-- 'no date' without dots; with or without dab
 	}
 local patterns_tags = {
 	'&lt;nowiki&gt;.-&lt;/nowiki&gt;',
 	'&lt;!%-%-.-%-%-&gt;',
 	'&lt;pre&gt;.-&lt;/pre&gt;',
 	'&lt;syntaxhighlight.-&gt;.-&lt;/syntaxhighlight&gt;',
 	'&lt;source.-&gt;.-&lt;/source&gt;',													-- deprecated alias of syntaxhighlight tag
 	}
 local template_skip = {															-- templates to be skipped for whatever reason; mostly because they resemble cs1-like templates
 	['Citation-attribution'] = true,
 	}
 local Article_content;
 
 local anchor_id_list = {};														-- exported tables
 local template_list = {};
 local article_whitelist = {};
 
 
 --[[--------------------------&lt; A R T I C L E _ C O N T E N T _ G E T &gt;----------------------------------------
 
 get article content, remove certain html-like tags and their content so that this code doesn't include any citation
 templates inside the tags as valid tagets; they are not.
 
 ]]
 
 local function article_content_get ()
 	if not Article_content then
 		Article_content = mw.title.getCurrentTitle():getContent() or '';		-- get the content of the article or ''; new pages edited w/ve do not have 'content' until saved; ve does not preview; phab:T221625
 		for _, tag in ipairs (patterns_tags) do
 			Article_content = Article_content:gsub (tag, '');					-- remove certain html-like tags and their content
 		end
 	end
 end
 
 
 --[[--------------------------&lt; S F N R E F _ G E T &gt;----------------------------------------------------------
 
 make an anchor id from the contents of {{sfnref}} or {{harvid}}.  this function assumes that {{sfnref}} and {{harvid}}
 are correctly formed.
 
 ]]
 
 local function sfnref_get (template)
 	template = template:gsub ('{{%s*(.-)%s*}}', '%1');							-- strip bounding template markup and trim
 	local parts = mw.text.split (template, '%s*|%s*');							-- split at the pipe and remove extraneous space characters
 	local anchor_id = {};
 
 	if redirects_sfnref[parts[1]:lower()] then
 		anchor_id[1] = 'CITEREF';
 	else
 		return nil;																-- not an sfnref or harvid template
 	end
 	
 	local i = 2;																-- indexer into parts{} table
 	local j = 2;																-- indexer into anchor_id{} table which already has 'CITEREF' at [1]
 	while parts[i] and 7 &gt; j do													-- loop through what should be just positional parameters for names and year (2-6 four names and a date)
 		if not parts[i]:find ('=') then											-- look for equal sign (named paraneter in a template that doesn't support named parameters)
 			anchor_id[j] = parts[i];											-- positional parameters are saved
 			j = j+1;															-- bump the anchor_id{} indexer
 		end
 		i = i+ 1;																-- bump the parts{} indexer
 	end
 
 	return table.concat (anchor_id, '');
 end
 
 
 --[[--------------------------&lt; D A T E _ G E T &gt;--------------------------------------------------------------
 
 extract year from one of |year=, |date=, |publicationdate=, or |publication-date in that order.  Does not error
 check (that is left to the cs1|2 templates to do)
 
 also gets date from |&lt;date alias&gt;={{date|...}}
 
 ]]
 
 local function date_get (template, aliases)
 	local date;
 	local rvalue;
 
 	for _, pattern in ipairs (aliases) do										-- spin through the date alias patterns
 		rvalue = tostring(template):match (pattern);							-- is this |&lt;date alias&gt;= used (tostring() because something makes match() think template is a table)
 		if rvalue then
 			rvalue = tostring(template):match (pattern .. '(%b{})');			-- is rvalue a template?
 			if rvalue then
 				rvalue = rvalue:gsub ('{{%s*(.-)%s*}}', '%1');					-- strip bounding template markup and trim
 				local parts = mw.text.split (rvalue, '%s*|%s*');				-- split at the pipe and remove extraneous space characters
 
 				if redirects_date[parts[1]:lower()] then						-- if parts[1] names {{date}} or redirect
 					rvalue = parts[2];											-- assume that date template is properly formed, first positional parameter is the date
 				else
 					return '';													-- |date= holds some other template than {{date}} or redirect
 				end
 			else
 				rvalue = template:match (pattern .. '([^|}]+)');
 				if rvalue then													-- if rvalue is something
 					rvalue = mw.text.trim (rvalue);								-- trim it
 				end
 				
 				if not rvalue or '' == rvalue then								-- if rvale was nothing or trimed to nothing
 					rvalue = nil;												-- ensure that it is unset so we can try the next parameter in the list
 				end
 			end
 
 			if rvalue then
 				for _, pattern in ipairs (patterns_date) do						-- spin through the recognized date formats
 					date = rvalue:match (pattern);								-- attempt to extract year portion according to the pattern
 					if date then
 						return date;											-- matched so return;
 					end
 				end
 				break;															-- found a date but it was malformed so abandon
 			end
 		end
 	end
 
 	return '';																	-- no date param or date param doesn't hold a recognized date; empty string for concatenation
 end
 
  
 --[[--------------------------&lt; V N A M E S _ G E T &gt;----------------------------------------------------------
 
 extract names from |vauthors= or |veditors=; there is no |vcontributors= parameter.
 
 splits the v parameter value at the comma; correctly handles accept-as-witten markup when used to wrap a comma-
 separated names (corporate)
 
 ]]
 
 local function vnames_get (params, vparam)
 	local vnames = {};															-- first four author or editor names go here
 	local split = {};															-- temp table to assist in decoding accept-as-witten-markup
 
 	if params[vparam] then														-- test for |vauthors= or |veditor=
 		split = mw.text.split (params[vparam], '%s*,%s*');						-- this will separate portions of ((Black, Brown, White, an Co.))
 	
 		local i = 1;															-- an indexer
 		
 		while split[i] do
 			if split[i]:match ('^%(%(.*[^%)][^%)]$') then						-- first segment of comma-separated accept-as-witten; this segment has the opening doubled parens
 				local name = split[i];
 				i=i+1;															-- bump indexer to next segment
 				while split[i] do
 					name = name .. ', ' .. split[i];							-- concatenate with previous segments
 					if split[i]:match ('^.*%)%)$') then							-- if this table member has the closing doubled parens
 						break;													-- and done reassembling so
 					end
 					i=i+1;														-- bump indexer
 				end
 				table.insert (vnames, name);									-- and add accept-as-witten name to the vnames table
 	
 			else
 				table.insert (vnames, split[i]);								-- and add name to the vnames table
 			end
 		i=i+1;																	-- bump indexer
 		if 5 == i then break; end												-- limit to four names
 		end
 
 		for i, vname in ipairs (vnames) do
 			if not vname:match ('%(%(.-%)%)') then								-- without accept-this-value-as-written markup
 				vnames[i] = vname:gsub ('(.-)%s+%u+$', '%1');					-- extract and save surname(s)
 			end
 		end
 		for i, vname in ipairs (vnames) do										-- repeat, this time for accept-this-value-as-written markup
 			vnames[i] = vname:gsub ('%(%((.-)%)%)', '%1');						-- remove markup if present and save the whole name
 		end
 	end
 
 	return 0 ~= #vnames and table.concat (vnames) or nil						-- return a concatenation of the vnames; nil else
 end
 
 
 --[[--------------------------&lt; N A M E S _ G E T &gt;------------------------------------------------------------
 
 cs1|2 makes anchor id from contributor, author, or editor name-lists in that order
 
 get the names from the cs1|2 template;  if there are no contributor names, try author names, then try editor names.
 
 returns concatenated names in enumeration order when successful; nil else
 
 empty name (nameholding parameter n is present without value) and missing name (nameholding parameter n is not
 present) are included as empty string with all other names
 
 ]]
 
 local function names_get (params, aliases_list)
 	local names = {};															-- first four author or editor names go here
 	local enum_alias;															-- alias with '#' replaced with a digit
 
 	for enum=1, 4 do															-- four names only
 		for i, alias in ipairs (aliases_list) do
 			if not names[enum] then												-- hanven't found a previous alias with this [enum]? see if we can find this alias with this enum
 				enum_alias = alias:gsub ('#', enum);							-- replace '#' to make 'lastn'
 	
 				if 1 == enum then												-- because |last= and last1= are exact aliases
 					if params[enum_alias] then									-- test |last1= first
 						names[enum] = params[enum_alias];						-- found so save the value assigned to |last1=
 						break;													-- next enum
 					else
 						enum_alias = alias:gsub ('#', '');						-- replace '#' to make 'last'
 						if params[enum_alias] then
 							names[enum] = params[enum_alias];					-- found so save the value assigned to |last=
 							break;												-- next enum
 						end
 					end
 				else															-- here for enum 2, 3, 4
 					if params[enum_alias] then
 						names[enum] = params[enum_alias];						-- found so save the value assigned to |lastn=
 						break;													-- next enum
 					end
 				end
 			end
 		end
 	end
 
 	for enum=1, 4 do															-- spin through the names table and
 		local name = names[enum];
 		if not name then														-- when nameholding parameter n is not present (nil)
 			name = '';															-- convert to empty string for concatenation
 		end
 		name = name:gsub('%(%((.-)%)%)', '%1');									-- remove accept-as-written markup if present
 		names[enum] = name;														-- save the modified name
 	end
 
 	local name_str = table.concat (names);										-- concatenate the names
 	return '' ~= name_str and name_str or nil;									-- return the concatenation if not empty string; nil else
 end
 
 
 --[[--------------------------&lt; T E M P L A T E _ S T R I P &gt;--------------------------------------------------
 
 removes the citation or havrc template's {{ and }} markup then removes, in whole, any templates found inside the
 citation or harvc template.
 
 Templates are not allowed in parameters that are made part of COinS metadata; yet, they will appear.  cs1|2 does
 not see the template markup but instead sees the result of the template as html.  cs1|2 strips the html which
 leaves the displayed value for the anchor id.  We can't do that here so, because templates aren't allowed in
 parameters, we simply discard any templates found in the cs1|2 template.
 
 this may leave a |lastn= parameter empty which will be treated as if it were really empty as cs1|2 do (three authors,
 |last2= empty -&gt; CITEREFLast1Last3YYYY (the harv and sfn render: 'Last1, &amp; Last3 YYYY' with CITEREFLast1Last3YYYY).
 
 ]]
 
 local function template_strip (template)
 	template = template:gsub ('^{{%s*', ''):gsub ('%s*}}$', '', 1);				-- remove outer {{ and }} (cs1|2 template delimiters with trailing/leading whitespace)
 	template = template:gsub ('%b{}', '');										-- remove any templates from the cs1|2 template
 	return template;
 end
 
 
 --[[--------------------------&lt; E S C A P E _ L U A _ M A G I C _ C H A R S &gt;----------------------------------
 
 Returns a string where all of lua's magic characters have been escaped.  This is important because functions like
 string.gsub() treat their pattern and replace strings as patterns, not literal strings.
 ]]
 
 local function escape_lua_magic_chars (argument)
 	argument = argument:gsub(&quot;%%&quot;, &quot;%%%%&quot;);										-- replace % with %%
 	argument = argument:gsub(&quot;([%^%$%(%)%.%[%]%*%+%-%?])&quot;, &quot;%%%1&quot;);				-- replace all other lua magic pattern characters
 	return argument;
 end
 
 
 --[=[-------------------------&lt; W I K I L I N K _ S T R I P &gt;--------------------------------------------------
 
 Wikilink markup does not belong in an anchor id and can / does confuse the code that parses apart citation and
 harvc templates so here we remove any wiki markup:
 	[[link|label]] -&gt; label
 	[[link]] -&gt; link
 	
 ]=]
 
 local function wikilink_strip (template)
 	for wikilink in template:gmatch ('%[%b[]%]') do								-- get a wikilink
 		template = template:gsub ('%[%b[]%]', '__57r1P__', 1);					-- install a marker
 		if wikilink:match ('%[%[.-|(.-)%]%]') then
 			wikilink = wikilink:match ('%[%[.-|(.-)%]%]');						-- extract label from complex [[link|label]] wikilink
 		else
 			wikilink = wikilink:match ('%[%[(.-)%]%]');							-- extract link from simple [[link]] wikilinks
 		end
 		wikilink = escape_lua_magic_chars (wikilink);							-- in case there are lua magic characters in wikilink
 		template = template:gsub ('__57r1P__', wikilink, 1);					-- replace the marker with the appropriate text
 	end
 
 	return template;
 end
 
 
 --[[--------------------------&lt; T E M P L A T E _ N A M E _ G E T &gt;--------------------------------------------
 
 return the citation or harvc template's name; convert to lower case and trim leading and trailing whitespace;
 
 when the template is a sandbox the subpage portion of the template name is omitted from the returned template name
 	{{Cite book/new |...}} returns cite book
 
 ]]
 
 local function template_name_get (template)
 	local template_name = template:match ('^{{%s*([^/|}]+)');					-- get template name; ignore subpages ~/new, ~/sandbox; parser functions
 
 	if not template_name or template_name:match ('^#') then						-- parser functions, magic words don't count as templates
 		return nil;																-- could not get template name from (possibly corrupt) template; extraneous opening { mid template can cause this;
 	end;
 	template_name = template_name:gsub ('%s*$', '');							-- trim trailing whitespace; leading whitespace already removed
 	return Lang_obj:ucfirst (template_name);									-- first character in template name must be uppercase (same as canonical template name) TODO: better way to do this?
 end
 
 
 --[[--------------------------&lt; T E M P L A T E _ P A R A M S _ G E T &gt;----------------------------------------
 
 parse apart a template's parameters and store in the params table where key is the parameter's name and value is
 the parameter's value; empty parameters are not saved
 
 ]]
 
 local function template_params_get (template, params_t)
 	template = wikilink_strip (template);										-- because piped wikilinks confuse code that builds params_t{} and because wikilinks not allowed in an anchor id
 																				-- strip templates after getting |ref= value because |ref={{sfnref}} and |ref={{harvid}} are allowed
 	template = template_strip (template);										-- because template markup can confuse code that builds params_t{} and because templates in name parameters are not allowed
 
 	local temp_t = mw.text.split (template, '%s*|%s*');							--split on the pipe
 	for _, param in ipairs (temp_t) do
 		if param:find ('=', 1, true) then										-- a named parameter?
 			local k, v = param:match ('%s*([^=]-)%s*=%s*([^|}]+)');
 			if v then															-- there must be a value
 				if '' ~= v and not v:match ('^%s$') then						-- skip when value is empty string or only whitespace
 					params_t[k] = mw.text.trim (v);								-- add trimmed value else
 				end
 			end
 		end
 	end
 end
 
 
 --[[--------------------------&lt; C I T E R E F _ M A K E _ H A R V C &gt;------------------------------------------
 
 makes anchor_id from {{harvc}} or redirects
 
 ]]
 
 local function anchor_id_make_harvc (template)
 	local date = date_get (template, alias_patterns_harvc_date);				-- get date; done here because might be in {{date}}; return date if valid; empty string else
 	local anchor_id;
 	local params = {};															-- table of harvc parameters
 	local id;																	-- custom anchor id for this {{harvc}} template
 
 	id = template:match ('|%s*id%s*=%s*(%b{})');								-- in case |id={{sfnref}}; done here because templates will be stripped
 
 	template_params_get (template, params);										-- build a table of template parameters and their values; this strips wikilinks and templates
 
 	if id then																	-- when set is {{sfnref}} or {{harvid}} template
 		return sfnref_get (id);													-- returns content of {{sfnref}} or {{harvid}}; nil else
 	end
 	if params.id then															-- custom anchor for this {{harvc}} template (text)
 		return params.id;														-- |id= value as written
 	end
 	
 	anchor_id = names_get (params, aliases_harvc_author);						-- get the harvc contributor names
 
 	if anchor_id then															-- if names were gotten
 		return 'CITEREF' .. anchor_id .. date;
 	end
 	return nil;																	-- no names; no anchor_id
 end
 
 
 --[[--------------------------&lt; A N C H O R _ I D _ M A K E _ W R A P P E R &gt;----------------------------------
 
 for wrapper templates
 
 inspect externally visible |ref= to decide what to do:
 	|ref=										- empty or missing: get names and date from whitelist defaults; override defaults from externally visible template parameters
 	|ref=harv									- same as empty or missing
 	|ref={{SfnRef|name|name|name|name|year}}	- assemble an anchor id from {{sfnref}} positional parameters
 	|ref={{Harvid|name|name|name|name|year}}	- assemble an anchor id from {{harvid}} positional parameters
 	|ref=none									- skip; do nothing because an anchor id intentionally suppressed; TODO: keep with a type code of '0'?
 	|ref=&lt;text&gt;									- save param value because may match an anchor id override value in {{harv}} template |ref= parameter or {{harvc}} |id= parameter
 
 ]]
 
 local function anchor_id_make_wrapper (template)
 	local ref;																	-- content of |ref=
 	local template_name;														-- name of the template
 	local anchor_id;															-- the assembled anchor id from this template
 	local date;
 	local name_default;
 	local date_default;
 	local vol;
 	local params = {};															-- table of template parameters
 	
 	template_name = template_name_get (template);								-- get first char uppercase trimmed template name; ignore subpages ~/new, ~/sandbox
 	if not template_name or template_skip[template_name] then
 		return nil;																-- could not extract template name from (possibly corrupted) template (extraneous opening { in the template will cause this)
 	end
 
 	date = date_get (template, alias_patterns_date);							-- get date; done here because might be in {{date}}
 --	if '' == date then
 --		date = whitelist.wrapper_templates[template_name][2] or '';				-- no externally visible date so get default date
 --	end
 
 	ref = template:match ('|%s*ref%s*=%s*(%b{})');								-- first look for |ref={{sfnref}} or |ref={{harvid}} because we will strip templates from the wrapper template
 	if not ref then
 		if template:match ('|%s*ref%s*=([^|}]+)') then							-- |ref={{template}} not found; if there is a |ref= param with an assigned value
 			ref = template:match ('|%s*ref%s*=([^|}]+)');						-- get the value; whitespace is a 'value'
 			if ref then															-- nil when |ref=|... or when |ref=}} (no spaces between assignment operator and pipe or closing brace)
 				ref = mw.text.trim (ref);										-- something, could be just whitespace, so trim leading / trailing whitespace
 				if '' == ref then												-- trimming a string of whitespace makes an empty string
 					ref = nil;													-- make empty ref same as missing ref
 				end
 			end
 		end
 	end
 
 	template_params_get (template, params);										-- build a table of template parameters and their values
 
 	if whitelist.wrapper_templates[template_name][1] then						-- is this wrapper a simple-default wrapper?
 		name_default = whitelist.wrapper_templates[template_name][1];			-- get the default names
 		date_default = whitelist.wrapper_templates[template_name][2];			-- get the default date
 	else
 		vol = params['volume'] or 'default';
 		if not whitelist.wrapper_templates[template_name][vol] then				-- make sure this volume exists
 			vol = 'default';													-- doesn't exist, use default volume
 		end
 		name_default = whitelist.wrapper_templates[template_name][vol][1];		-- get the default names
 		date_default = whitelist.wrapper_templates[template_name][vol][2];		-- get the default date
 	end
 
 	if 'harv' == ref  or not ref then											-- |ref=harv specified or |ref= missing or empty
 		anchor_id = names_get (params, aliases_contributor) or					-- get contributor, author, or editor names
 			names_get (params, aliases_author) or
 			vnames_get (params, 'vauthors') or									-- |vauthors=
 			names_get (params, aliases_editor) or
 			vnames_get (params, 'veditors') or									-- |veditors=
 			name_default;														-- default names from whitelist
 --			whitelist.wrapper_templates[template_name][1];						-- default names from whitelist
 
 		if '' == date then														-- if date not provided in the template
 			date = date_default;												-- use the default date from whitelist
 		end
 
 		if anchor_id then														-- if names were gotten
 			anchor_id = 'CITEREF' .. anchor_id .. date;
 		end
 
 	elseif ref:match ('%b{}') then												-- ref holds a template
 		anchor_id = sfnref_get (ref);											-- returns content of {{sfnref}} or {{harvid}}; nil else
 
 	elseif 'none' == ref then													-- |ref=none
 		return nil;																-- anchor id expicitly suppressed
 		
 	else
 		anchor_id = ref;														-- |ref=&lt;text&gt; may match an anchor id override value in {{harv}} template |ref= parameter
 	end
 	
 	return anchor_id;															-- anchor_id text; nil else
 end
 
 
 --[[--------------------------&lt; A N C H O R _ I D _ M A K E _ C S 1 2 &gt;----------------------------------------
 
 for cs1|2 template and cs1-like templates
 
 inspect |ref= to decide what to do:
 	|ref=										- empty or missing: get names and date from template parameters; all cs1|2 create CITEREF anchor IDs
 	|ref=harv									- get names and date from template parameters
 	|ref={{SfnRef|name|name|name|name|year}}	- assemble an anchor id from {{sfnref}} positional parameters
 	|ref={{Harvid|name|name|name|name|year}}	- assemble an anchor id from {{harvid}} positional parameters
 	|ref=none									- skip; do nothing because an anchor id intentionally suppressed; TODO: keep with a type code of '0'?
 	|ref=&lt;text&gt;									- save param value because may match an anchor id override value in {{harv}} template |ref= parameter or {{harvc}} |id= parameter
 
 ]]
 
 local function anchor_id_make_cs12 (template)
 	local ref;																	-- content of |ref=
 	local template_name;														-- name of the template
 	local anchor_id;															-- the assembled anchor id from this template
 	local date;
 	local params = {};															-- table of template parameters
 	
 	template_name = template_name_get (template);								-- get first char uppercase trimmed template name; ignore subpages ~/new, ~/sandbox
 	if not template_name or template_skip[template_name] then
 		return nil;																-- could not extract template name from (possibly corrupted) template (extraneous opening { in the template will cause this)
 	end
 
 	if redirects_patent[template_name] then
 		date = date_get (template, alias_patterns_patent_date);					-- get date; done here because might be in {{date}} 
 	else
 		date = date_get (template, alias_patterns_date);
 	end
 	
 	ref = template:match ('|%s*ref%s*=%s*(%b{})');								-- first look for |ref={{sfnref}} or |ref={{harvid}} because we will strip templates from the cs1|2 template
 	if not ref then
 		if template:match ('|%s*ref%s*=([^|}]+)') then							-- |ref={{template}} not found; if there is a |ref= param with an assigned value
 			ref = template:match ('|%s*ref%s*=([^|}]+)');						-- get the value; whitespace is a 'value'
 			if ref then															-- nil when |ref=|... or when |ref=}} (no spaces between assignment operator and pipe or closing brace)
 				ref = mw.text.trim (ref);										-- something, could be just whitespace, so trim leading / trailing whitespace
 				if '' == ref then												-- trimming a string of whitespace makes an empty string
 					ref = nil;													-- make empty ref same as missing ref
 				end
 			end
 		end
 	end
 
 	template_params_get (template, params);										-- build a table of template parameters and their values
 
 	if not ref then																-- |ref= not set, might be cite LSA which doesn't support |ref=
 		if 'cite lsa' == template_name then
 			return 'CITEREF' .. (params.last or '') .. (params.year or '');		-- cite LSA always creates an anchor id using only |last= and |year= (no aliases)
 		end
 	end
 
 	if 'harv' == ref  or not ref then											-- |ref=harv specified or |ref= missing or empty
 		if redirects_patent[template_name] then									-- if this is a cite patent template
 			anchor_id = names_get (params, aliases_inventor);					-- inventor names only
 		else																	-- cs1|2 template
 			anchor_id = names_get (params, aliases_contributor) or				-- get contributor, author, or editor names
 				names_get (params, aliases_author) or
 				vnames_get (params, 'vauthors') or								-- |vauthors=
 				names_get (params, aliases_editor) or
 				vnames_get (params, 'veditors');								-- |veditors=
 		end
 
 		if anchor_id then														-- if names were gotten
 			anchor_id = 'CITEREF' .. anchor_id .. date;
 		end
 
 	elseif ref:match ('%b{}') then												-- ref holds a template
 		anchor_id = sfnref_get (ref);											-- returns content of {{sfnref}} or {{harvid}}; nil else
 
 	elseif 'none' == ref and not redirects_patent[template_name] then			-- |ref=none; not supported by cite patent
 		return nil;																-- anchor id expicitly suppressed
 		
 	else
 		anchor_id = ref;														-- |ref=&lt;text&gt; may match an anchor id override value in {{harv}} template |ref= parameter
 	end
 	
 	return anchor_id;															-- anchor_id text; nil else
 end
 
 
 --[[--------------------------&lt; L I S T _ A D D &gt;--------------------------------------------------------------
 
 adds an &lt;item&gt; to &lt;list&gt; table; for anchor IDs, the boolean &lt;encode&gt; argument must be set true; no return value
 
 ]]
 
 local function list_add (item, list, encode)
 	if item then																-- if there was an item
 		if encode then															-- for anchor IDs ...
 			item = mw.uri.anchorEncode (item);									-- encode to remove wikimarkup, convert spaces to underscores etc
 		end
 		
 		if not list[item] then													-- if not already saved
 			list[item] = 1;														-- save it 
 		else																	-- here when this item already saved
 			list[item] = list[item] + 1;										-- to indicate that there are multiple items
 		end
 	end
 end
 
 
 --[[--------------------------&lt; A N C H O R _ I D _ M A K E _ A N C H O R &gt;------------------------------------
 
 make anchor IDs from {{anchor}}; there may be more than one because {{anchor}} is not limited to the number of
 anchors it may hold.
 
 ]]
 
 local function anchor_id_make_anchor (template, anchor_id_list)
 	template = template:gsub ('^{{[^|]+|', ''):gsub ('}}$', '', 1);				-- remove outer {{ and }} and template name
 
 	template = wikilink_strip (template);										-- strip any wikilink markup (there shouldn't be any but just in case)
 	
 	local params = {};
 	local anchor_id;
 	
 	for param in template:gmatch ('%b{}') do									-- loop through the template; remove and save templates (presumed to be sfnref or harvid)
 		table.insert (params, param);											-- save it
 		template = template:gsub ('%b{}', '', 1);								-- remove it from source template
 	end
 	
 	for _, t in ipairs (params) do												-- spin through the templates in params
 		anchor_id = sfnref_get (t);												-- attempt to decode {{sfnref}} and {{harvid}}
 		if anchor_id then														-- nil when not {{sfnref}} or {{harvid}}
 			list_add (anchor_id, anchor_id_list, true);							-- add anchor ID to the list
 		end
 	end
 	
 	template = template:gsub ('|%s*|', '|');									-- when pipe follows pipe with or without white space, remove extraneous pipe
 	template = template:gsub ('^|', ''):gsub('|$', '');							-- remove extraneous leading and trailing pipes
 
 	params = mw.text.split (template, '%s*|%s*');								-- split at the pipe and remove extraneous space characters
 	
 	for _, t in ipairs (params) do												-- spin through the anchor IDs
 		anchor_id = mw.text.trim (t);											-- trim white space
 		if '' ~= anchor_id then													-- should always have something
 			list_add (anchor_id, anchor_id_list, true);							-- add anchor ID to the list
 		end
 	end
 end
 
 
 --[[--------------------------&lt; T E M P L A T E _ L I S T _ A D D &gt;--------------------------------------------
 
 makes a list of templates use in the article.
 
 ]]
 
 local function template_list_add (template)
 	local template = template:match ('{{%s*(.-)[|}]');							-- keep the case of the template - this is different from template_name_get()
 	if template and not template:match ('^#') then								-- found a template or magic word; ignore magic words
 		template=mw.text.trim (template);										-- trim whitespace
 		template = Lang_obj:ucfirst (template);									-- first character in template name must be uppercase (same as canonical template name) TODO: better way to do this?
 		list_add (template, template_list);										-- add to list with (unused) tally
 	end
 end
 
 
 --[[--------------------------&lt; A N C H O R _ I D _ L I S T _ M A K E &gt;----------------------------------------
 
 makes a list of anchor ids from cs1|2, cs1|2-like, vcite xxx, harvc, anchor, wikicite templates
 
 Because cs1|2 wrapper templates can, and often do, hide the author and date parameters inside the wrapper,
 these parameters are not available in the article's wikisource so {{harv}}, {{sfn}}, and {{harvc}} templates that
 link correctly to those wrapper templates will incorrectly show error messages.  Use |ignore-err=yes in the {{harv}},
 {{sfn}}, and {{harvc}} templates to supress the error message.
 
 creates a list of templates used in the article for use with the whitelist
 
 creates a list of article-local whitelisted anchor IDs from {{sfn whitelist}}
 
 ]]
 
 local function anchor_id_list_make ()
 	article_content_get ();														-- attempt to get this article's content
 
 	if '' == Article_content then												-- when there is no article content
 		return '';																-- no point in continuing
 	end
 	
 	local template;																-- place to hold the template that we found
 	local template_name;
 	local anchor_id;															-- place to hold an anchor id as it is extracted / decoded
 
 	local find_pattern = '%f[{]{{[^{]';
 	local tstart, tend = Article_content:find (find_pattern);					-- find the first template; do not find template variables: {{{template var|}}} 
 
 	while tstart do
 		template = Article_content:match ('%b{}', tstart);						-- get the whole template
 		if not template then
 			break;																-- template is nil for some reason (last template missing closing }} for example) so declare ourselves done
 		end
 
 		template_name = template_name_get (template);							-- get first char uppercase trimmed template name; ignore subpages ~/new, ~/sandbox
 		template_list_add (template);											-- add this template's name to the list
 
 		if data.known_templates_cs12 [template_name] then
 			anchor_id = anchor_id_make_cs12 (template);							-- extract an anchor id from this template
 			list_add (anchor_id, anchor_id_list, true)
 
 		elseif data.known_templates_vcite [template_name] then
 			local ref = template:match ('|%s*ref%s*=%s*(%b{})');				-- first look for |ref={{sfnref}} or |ref={{harvid}} because we will strip templates from the vcite template
 			if ref then															-- |ref={{template}}
 				anchor_id = sfnref_get (ref);									-- returns content of {{sfnref}} or {{harvid}}; nil else
 				list_add (anchor_id, anchor_id_list, true);
 			else
 				local params = {};
 
 				template_params_get (template, params);							-- build a table of template parameters and their values
 
 				anchor_id = params['ref'];										-- when both set, vcite uses value from |ref=
 				if not anchor_id and params['harvid'] then
 					anchor_id = 'CITEREF' .. params['harvid'];					-- in vcite, |harvid= auto-adds 'CITEREF' prefix to the value in |harvid=
 				end
 				list_add (anchor_id, anchor_id_list, true);
 			end
 
 		elseif data.known_templates_harvc [template_name] then
 			anchor_id = anchor_id_make_harvc (template);						-- extract an anchor id from this template
 			list_add (anchor_id, anchor_id_list, true);
 			
 		elseif data.known_templates_wikicite [template_name] then
 			local ref = template:match ('|%s*ref%s*=%s*(%b{})');				-- first look for |ref={{sfnref}} or |ref={{harvid}}
 			
 			if ref then
 				anchor_id = sfnref_get (ref);
 	
 			elseif template:match ('|%s*ref%s*=([^|}]+)') then
 				anchor_id = template:match ('|%s*ref%s*=([^|}]+)');				-- plain-text
 	
 			elseif template:match ('|%s*id%s*=%s*(%b{})') then
 				ref = template:match ('|%s*id%s*=%s*(%b{})');
 				anchor_id = 'Reference-' .. sfnref_get (ref);
 
 			elseif template:match ('|%s*id%s*=([^|}]+)') then
 				anchor_id = 'Reference-' .. template:match ('|%s*id%s*=([^|}]+)');	-- plain-text
 
 			else
 				anchor_id = nil;												-- no matches, ensure that anchor_id has no value
 			end
 			
 			if anchor_id then
 				list_add (anchor_id, anchor_id_list, true);
 			end
 
 		elseif data.known_templates_anchor [template_name] then
 			anchor_id_make_anchor (template, anchor_id_list);					-- extract anchor ids from this template if any
 		
 		elseif data.known_templates_sfn_whitelist [template_name] then
 			template = template:gsub ('^{{[^|]+|', ''):gsub ('}}$', '', 1);		-- remove outer {{ and }} and template name
 			template = mw.text.trim (template, '%s|');							-- trim leading trailing white space and pipes
 			template = mw.text.split (template, '%s*|%s*');						-- make a table of the template's parameters
 
 			for _, anchor_id in ipairs (template) do							-- spin through this template's parameter
 				if '' ~= anchor_id and not article_whitelist[anchor_id] then
 					anchor_id = mw.uri.anchorEncode (anchor_id)
 					article_whitelist[anchor_id] = 1;							-- add to the whitelist
 				end
 			end
 		
 		elseif template_name and whitelist.wrapper_templates[template_name] then
 			anchor_id = anchor_id_make_wrapper (template);						-- extract an anchor id from this template if possible
 			list_add (anchor_id, anchor_id_list, true);
 
 		elseif template_name and template_name:match ('^Cit[ea]') then			-- not known, not known wrapper; last gasp, try as cs1-like
 			anchor_id = anchor_id_make_cs12 (template);							-- extract an anchor id from this template if possible
 			list_add (anchor_id, anchor_id_list, true);
 		end
 
 		tstart, tend = Article_content:find (find_pattern, tend);				-- search for another template; begin at end of last search
 	end
 
 mw.logObject (anchor_id_list, 'anchor_id_list');
 mw.logObject (template_list, 'template_list');
 mw.logObject (article_whitelist, 'article_whitelist');
 
 	return anchor_id_list;
 end
 
 
 --[[--------------------------&lt; E X P O R T E D _ T A B L E S &gt;------------------------------------------------
 ]]
 
 return {
 	anchor_id_list = anchor_id_list_make(),										-- table of anchor ids available in this article
 	article_whitelist = article_whitelist,										-- table of anchor ids with false-positive error message to be suppressed
 	template_list = template_list,												-- table of templates used in this article