Editing Module:Track gauge/autodocument

-- This module documents the track gauges
-- as defined in [[module:Track gauge/data]].
-- General note: "id" is the size-id (in mm). With this id, definitions can vary (mm, ft/in, name)
-- Alias (the normalised input value) is the primary search term
local p = {}
local getArgs = require('Module:Arguments').getArgs
local modMath = require('Module:Math')
local modTrackGauge = require('Module:Track gauge') -- /andbox here
local dataPageName = 'Module:Track gauge/data' -- /sandbox here

local gaugeDataAll = nil
local tableTools = require('Module:tableTools')
-- global counters (to keep between the id-row building calls)
local ttlSizeClassCount = {}
local ttlAliasCount = 0
local ttlEntries = 0
local ttlUnitCount = {}
local ttlAltNameCount = 0
local ttlAltName = {}
local ttlLinkCount = 0
local ttlContentCatsCount = 0
local ttlMentioningCatsCount = 0
local ttlMentioningPageCount = 0
local ttlListedRange = {}
-----------------------------------------------------------------------------------
-- prepareArgs -- Arguments coming from an #invoke or from a module
-----------------------------------------------------------------------------------
local function prepareArgs(frame)
	local origArgs = getArgs(frame)
	-- Trim whitespace, make lower-case and remove blank arguments for all arguments
	-- searchAlias is the cleaned value of [1]. [1] is kept as rawInput for error message
	local args = {}
	args['searchAlias'] = ''
	args['rawInput'] = origArgs[1] or ''

	for k, v in pairs(origArgs) do
		if tonumber(k) == nil then
			-- Named argument
			if k == 'docsortlabel' then -- not in TG
				args[k] = v
			else
				args[k] = mw.ustring.lower(v)
			end
		else
			-- Unnamed argument, alias to be searched
			args[k] = modTrackGauge.normaliseAliasInput(v)
			if k == 1 then
				args['searchAlias'] = args[1]
			end
		end
	end

	return args
end
-----------------------------------------------------------------------------------
-- formatUnitPlaintext
-- Pattern '00016.5 mm' for table.sort and catsort.
-----------------------------------------------------------------------------------
local function formatUnitPlaintext(tgEntry, unit, fmtZeroPadding, toFracChar)
	-- Returns plaintext (ASCII) only. No css.
	if tgEntry == nil then
		return ''
	end
	if (unit or tgEntry.def) == 'imp' then
		-- imperial
		local ft = ''
		local inch = ''
		local frac = ''
		if tgEntry.ft then
			ft = tgEntry.ft .. ' ft'
		end
		if tgEntry.num then
			frac = ' ' .. tgEntry.num .. '/' .. tgEntry.den
			if toFracChar then
				-- as used in contentCat pagenames
				if frac == ' 1/8' then frac = '⅛'
				elseif frac == ' 1/4' then frac = '¼'
				elseif frac == ' 3/8' then frac = '⅜'
				elseif frac == ' 1/2' then frac = '½'
				elseif frac == ' 3/4' then frac = '¾'
				elseif frac == ' 7/8' then frac = '⅞'
				else
					frac = frac .. ' (error: fraction character missing in module:Track gauge)'
				end
			end
			if tgEntry['in'] then
				frac = ' ' .. tgEntry['in'] .. frac .. ' in'
			else
				frac = ' ' .. frac .. ' in'
			end
		else
			if tgEntry['in'] then
				inch = ' ' .. tgEntry['in'] .. ' in'
			end
		end
		return mw.text.trim(ft .. inch .. frac)
	else
		-- metric (mm)
		if fmtZeroPadding == nil or tonumber(fmtZeroPadding) <= 0 then
			return tgEntry.id .. ' mm'
		else
			return string.rep('0', fmtZeroPadding - math.floor(math.log10(tonumber(tgEntry.id))) - 1)
				.. tgEntry.id .. ' mm'
		end
	end
end
-----------------------------------------------------------------------------------
-- document data-sort-value
-----------------------------------------------------------------------------------
local function documentdatasortvalue(tgEntry)
	local s = formatUnitPlaintext(tgEntry, 'met', 5)
	return tostring(mw.html.create():tag('span'):attr('data-sort-value', s))
end
-----------------------------------------------------------------------------------
-- catSortFromTitle
-- Currently finds "600 mm" when at end of title, then returns "0600 mm" (for catSort).
-- Blank when not found. Used for cat:mentions category page.
-----------------------------------------------------------------------------------
function p.catSortFromTitle()
	local title = mw.title.getCurrentTitle()
	local catSort = string.match(title.text, '%s(%d+%.?%d*)%smm$') or ''
	if catSort ~= '' then
		catSort = string.rep('0', 4 - math.floor(math.log10(tonumber(catSort))) - 1)
			.. catSort .. ' mm'
	end
	if catSort == '' then
		return '*'
	else
		return catSort
	end
end
-----------------------------------------------------------------------------------
-- documentGaugeClass
-----------------------------------------------------------------------------------
local function documentGaugeClass(tgEntry, countMentionings)
	local size = tonumber(tgEntry.id or 0)
	local j
	if size > 1435 then
		j = 5
	elseif size == 1435 then
		j = 4
	elseif size > 500 then
		j = 3
	elseif size >= 100 then
		j = 2
	elseif size > 0 then
		j = 1
	else
		j = 6
	end
	ttlSizeClassCount[j][2] = ttlSizeClassCount[j][2] +1
	ttlSizeClassCount[j][4] = ttlSizeClassCount[j][4] + (countMentionings or 0)
	return '<span data-sort-value="' .. j .. '">' .. ttlSizeClassCount[j][1] .. '</span>' --(20190920: linter closing span added)
end
-----------------------------------------------------------------------------------
-- anchor -- Anchor text *here* is: <span id="1000 mm">; anchor *there* should be: #1000 mm.
-----------------------------------------------------------------------------------
local function anchor(tgEntry, unit, herethere)
	if tgEntry == nil then
		return ''
	end
	unit = unit or tgEntry.def1
	local anch = formatUnitPlaintext(tgEntry, unit, 0)
	if herethere == 'there' then -- Untested, April 2014
		anch = '#' .. anch
	else
		anch = mw.html.create():tag('span'):attr('id', anch)
	end
	return tostring(anch)
end
-----------------------------------------------------------------------------------
-- noWrap -- Add span tags to prevent a string from wrapping.
-----------------------------------------------------------------------------------
local function noWrap(s)
	return mw.ustring.format('<span class="nowrap">%s</span>', s)
end
-----------------------------------------------------------------------------------
-- frac -- A slimmed-down version of the {{frac}} template (a single nowrap to be added with the unit)
-----------------------------------------------------------------------------------
local function frac(whole, num, den)
	local templatestyles = mw.getCurrentFrame():extensionTag{
		name = 'templatestyles', args = { src = 'Fraction/styles.css' }
	}
	return mw.ustring.format(
		'%s<span class="frac" role="math">%s<span class="num">%s</span>&frasl;<span class="den">%s</span></span>',
		templatestyles,
		whole and (whole .. '<span class="sr-only">+</span>') or '',
		num,
		den
	)
end

-----------------------------------------------------------------------------------
-- debugReturnArgs
-----------------------------------------------------------------------------------
function p.debugReturnArgs(frame)
	local args = prepareArgs(frame)
	local retArgs = {}
	for k, a in pairs(args) do
		table.insert(retArgs, k .. '=' .. a)
	end
	return 'Args: ' .. table.concat(retArgs, '; ')
end
-----------------------------------------------------------------------------------
-- checkData -- Public. Performs various checks on the /data subpage.
-- not maintained since ca. 2015
-----------------------------------------------------------------------------------
function p.checkData(frame)
	--To be allowed: entry.link empty; then use entry.name.
	local dataPage = frame and frame.args and frame.args[1] or dataPageName
	local data = mw.loadData(dataPage)
	local exists, dupes, dupeSort, ret = {}, {}, {}, {}
	-- Check for duplicate aliases.
	for ti, t in ipairs(data) do
		for ai, alias in ipairs(t.aliases or {}) do
			if not exists[alias] then
				exists[alias] = { ti, ai }
			else
				if not dupes[alias] then
					dupes[alias] = { exists[alias] }
				end
				table.insert(dupes[alias], { ti, ai })
			end
		end
	end
	for alias in pairs(dupes) do
		table.insert(dupeSort, alias)
	end
	table.sort(dupeSort)
	for i1, alias in ipairs(dupeSort) do
		local positions = {}
		for i2, aliasKeys in ipairs(dupes[alias]) do
			local position = mw.ustring.format('gauge %d, alias %d (gauge id: <code>%s</code>)', aliasKeys[1], aliasKeys[2], data[aliasKeys[1]].id or '')
			table.insert(positions, position)
		end
		local aliasText = mw.ustring.format('Duplicate aliases "%s" detected at the following positions: %s.', alias, mw.text.listToText(positions, '; '))
		table.insert(ret, aliasText)
	end
	-- Check for numerators without denominators.
	for ti, t in ipairs(data) do
		local num = t.num
		local den = t.den
		if num and not den then
			table.insert(ret, mw.ustring.format('Numerator "%s" with no denominator detected at gauge %d (id: <code>%s</code>).', num, ti, t.id or ''))
		elseif den and not num then
			table.insert(ret, mw.ustring.format('Denominator "%s" with no numerator detected at gauge %d (id: <code>%s</code>).', den, ti, t.id or ''))
		end
	end
	-- Check for gauges with no imperial or no metric measurements.
	for ti, t in ipairs(data) do
		if not (t.ft or t['in'] or t.num or t.den) then
			table.insert(ret, mw.ustring.format('No imperial measurements found for gauge %d (id: <code>%s</code>).', ti, t.id or ''))
		end
		if not (t.m or t.mm) then
			table.insert(ret, mw.ustring.format('No metric measurements found for gauge %d (id: <code>%s</code>).', ti, t.id or ''))
		end
	end
	-- Check for non-numeric measurements.
	local measurements = { 'ft', 'in', 'num', 'den', 'm', 'mm' }
	for ti, t in ipairs(data) do
		for mi, measurement in ipairs(measurements) do
			local measurementVal = t[measurement]
			if measurementVal and not tonumber(measurementVal) then
				table.insert(ret, mw.ustring.format('Non-numeric <code>%s</code> measurement ("%s") found for gauge %d (id: <code>%s</code>).', measurement, measurementVal, ti, t.id or ''))
			end
		end
	end
	-- Check for gauges with no id.
	for ti, t in ipairs(data) do
		if not t.id then
			local aliases = {}
			for i, alias in ipairs(t.aliases) do
				table.insert(aliases, mw.ustring.format('<code>%s</code>', alias))
			end
			aliases = mw.ustring.format(' (aliases: %s)', mw.text.listToText(aliases))
			table.insert(ret, mw.ustring.format('No id found for track gauge %d%s.', ti, aliases or ''))
		end
	end
	-- Check for gauges with no aliases.
	for ti, t in ipairs(data) do
		if type(t.aliases) ~= 'table' then
			table.insert(ret, mw.ustring.format('No aliases found for gauge %d (id: <code>%s</code>).', ti, t.id or ''))
		else
			local isAlias = false
			for ai, alias in ipairs(t.aliases) do
				isAlias = true
				break
			end
			if not isAlias then
				table.insert(ret, mw.ustring.format('No aliases found for gauge %d (id: <code>%s</code>).', ti, t.id or ''))
			end
		end
	end
	-- Check for named gauges with no links and gauges with links but no names.
	-- 20140520: no link? could be acceptable. Code falls back to the unlinked name (in test now).
	if false then -- skipped 2014-05-25
	for ti, t in ipairs(data) do
		if t.name and not t.link then
				table.insert(ret, mw.ustring.format('No link found for the named gauge "%s" at position %d (id: <code>%s</code>).', t.name, ti, t.id or ''))
		elseif t.link and not t.name then
				table.insert(ret, mw.ustring.format('No name found for the gauge with link "%s" at position %d (id: <code>%s</code>).', t.link, ti, t.id or ''))
		end
	end
	end
	-- Check for invalid def1 values.
	for ti, t in ipairs(data) do
	local def = t.def1
		if def ~= 'imp' and def ~= 'met' then
			table.insert(ret, mw.ustring.format('Invalid def1 value "%s" found for gauge %d (id: <code>%s</code>).', def or '', ti, t.id or ''))
		end
	end
	-- Check for unwanted whitespace.
	for ti, t in ipairs(data) do
		for tkey, tval in pairs(t) do
			if tkey == 'aliases' and type(tval) == 'table' then
				for ai, alias in ipairs(tval) do
					if mw.ustring.find(alias, '%s') then
						table.insert(ret, mw.ustring.format('Unwanted whitespace detected in gauge %d alias %d ("%s", gauge id: <code>%s</code>).', ti, ai, alias, t.id or ''))
					end
				end
			elseif tkey == 'name' or tkey == 'link' or tkey == 'pagename' or tkey == 'contentcat' then
				if tval ~= mw.text.trim(tval) then
					table.insert(ret, mw.ustring.format('Unwanted whitespace detected in <code>%s</code> field of gauge %d ("%s", gauge id: <code>%s</code>).', tkey, ti, tval, t.id or ''))
				end
			elseif mw.ustring.find(tval, '%s') then
				table.insert(ret, mw.ustring.format('Unwanted whitespace detected in <code>%s</code> field of gauge %d ("%s", gauge id: <code>%s</code>).', tkey, ti, tval, t.id or ''))
			end
		end
	end
	-- Added April 2014: alias should not double with another id (imp and mm not ambiguous)
	local self_id = ''
	local self_def = ''
	for ti, t in ipairs(data) do
		self_id = t.id
		self_def = t.def1
		for iC, aliasCheck in ipairs(t.aliases) do
			if tonumber(aliasCheck) ~= nil then
				if self_id ~= aliasCheck then
					for iTwo, tTwo in ipairs(data) do
						if aliasCheck == tTwo.id then
							table.insert(ret,
								mw.ustring.format('Input alias %s (%s) from <code>id=%s mm</code> ambiguous with gauge id=<code>%s mm</code> (%s)'
								, aliasCheck, self_def, self_id, tTwo.id, tTwo.def1)
								)
						end
					end
				end
			end
		end
	end
	 -- Return any errors found.
	for i, msg in ipairs(ret) do
		ret[i] = mw.ustring.format('<span class="error">%s</span>', msg)
	end
	if #ret > 0 then
		return mw.ustring.format('Found the following errors in %s:\n* %s', dataPage, table.concat(ret, '\n* '))
	else
		return mw.ustring.format('No errors found in %s.', dataPage)
	end
end
-----------------------------------------------------------------------------------
-- catContent -- content category for the gauge
-----------------------------------------------------------------------------------
function p.catContent(frame)
	-- catContent (content category for this alias)
	-- can be hardcoded in the data, or build by size (pattern)
	local args = prepareArgs(frame)
	local tgEntry = modTrackGauge.getTrackGaugeEntry(args.searchAlias)
	if tgEntry == nil then
		return args['displaynotfound'] or 'No gauge entry found for ' .. (args[1] or '""')
	end
	local catTitle
	local label
	local catC
	local docsortlabel = ''
	if args.docsortlabel ~= nil then
		docsortlabel = '|' .. args.docsortlabel
	end
	if tgEntry.contentcat == '' then
		catC = ''
	elseif tgEntry.contentcat ~= nil then
		catC = '[[:Category:' .. tgEntry.contentcat .. docsortlabel .. ']]'
	else -- no name given, try default name:
		local catCsuffix = ' gauge railways'
		if tgEntry.def1 == 'met' then
			label = formatUnitPlaintext(tgEntry, 'met')
			catTitle = mw.title.makeTitle(14, label .. catCsuffix)
			if catTitle.exists then
				catC = '[[:' .. catTitle.fullText .. docsortlabel .. ']]'
			end
		elseif tgEntry.def1 == 'imp' then
			label = formatUnitPlaintext(tgEntry, 'imp', nil, true)
			catTitle = mw.title.makeTitle(14, label .. catCsuffix)
			if catTitle.exists then
				catC = '[[:' .. catTitle.fullText .. docsortlabel .. ']]'
			end
		end
	end
	return catC
end
-----------------------------------------------------------------------------------
-- catMentions -- maintenance only
-----------------------------------------------------------------------------------
function p.catMentions(frame)
	local args = prepareArgs(frame)
	local tgEntry = modTrackGauge.getTrackGaugeEntry(args.searchAlias)
	if tgEntry == nil then
		return args['displaynotfound'] or 'No gauge entry found for ' .. (args[1] or '""')
	end
	local catM = modTrackGauge.catMentions(tgEntry, args.docsortlabel, 'show')
	return catM
end
-----------------------------------------------------------------------------------
-- fromInputToId -- Used cleaned Alias as searchkey
-----------------------------------------------------------------------------------
local function fromInputToId(searchAlias)
	gaugeDataAll = mw.loadData(dataPageName)
	for i, tgEntry in ipairs(gaugeDataAll) do
		for j, alias in ipairs(tgEntry.aliases) do
			if alias == searchAlias then
				return tgEntry.id
			end
		end
	end
	-- Next search: by id (autodocument only, not in main RG)
	if tonumber(searchAlias) ~= nil then
		for i, tgEntry in ipairs(gaugeDataAll) do
			if tgEntry.id == searchAlias then
				return tgEntry.id
			end
		end
	end
end
-----------------------------------------------------------------------------------
-- documentInchCount -- Number of inches in decimals.
-----------------------------------------------------------------------------------
local function documentInchCount(tgEntry)
	local inches = 0
	if tgEntry['num'] ~= nil then
		inches = modMath._round(tonumber((tgEntry['num'] or 0) / (tgEntry['den'] or 1)), 4)
	end
	inches = tostring((tonumber(tgEntry['ft'] or 0) * 12)
		+ tonumber(tgEntry['in'] or 0) + inches)
	return inches
end
-----------------------------------------------------------------------------------
-- documentInchToMm -- Not used lately
-----------------------------------------------------------------------------------
local function documentInchToMm(inchCount)
	return tonumber(inchCount or 0) * 25.4
end
-----------------------------------------------------------------------------------
-- documentGaugeSizeFromTitle -- Currently finds "1620 mm" when at end of title,
-- then returns "1620". Blank when not found.
-----------------------------------------------------------------------------------
function p.documentGaugeSizeFromTitle()
	local title = mw.title.getCurrentTitle()
	return string.match(title.text, '%s(%d+%.?%d*)%smm$') or ''
end
-----------------------------------------------------------------------------------
-- documentBuildTgList -- The table of id's to fill the table
-----------------------------------------------------------------------------------
function documentBuildTgList(args)
	-- Build series from the list. idFrom and idTo are numerical
	local tgList = {}
	local idFrom = -1
	local idTo = -1
	for i, v in ipairs(args) do
		if v == 'all' then
			idFrom = -math.huge
			idTo = math.huge
			break
		end
	end
	if args.docfrom ~= nil then
		idFrom = tonumber(fromInputToId(args.docfrom)
			or mw.ustring.gsub(args.docfrom, 'mm', ''))
		idTo = math.huge
	end
	if args.docto ~= nil then
		idTo = tonumber(fromInputToId(args.docto)
			or mw.ustring.gsub(args.docto, 'mm', ''))
	end
	if idTo > 0 then -- Some subset is requested from the whole data set
		if idFrom > idTo then
			local dummy = idFrom
			idFrom = idTo
			idTo = dummy
		end
		for i, tgEntry in ipairs(gaugeDataAll) do
			if (tonumber(tgEntry.id) >= idFrom) and (tonumber(tgEntry.id) <= idTo) then

				table.insert(tgList, tonumber(tgEntry.id))
			end
		end
		tgList = tableTools.removeDuplicates(tgList)
		table.sort(tgList)
		if #tgList > 1 then
			ttlListedRange[1] = tgList[1] .. ' mm &ndash; ' .. tgList[#tgList] .. ' mm '
		end
	end
	-- Individual entries can be mentioned in args (all unnamed = numbered params)
	-- Need a straight table.to keep sequence right
	local id
	local argsAliasesIn = tableTools.compressSparseArray(args)
	for i, argsAlias in ipairs(argsAliasesIn) do
		id = fromInputToId(argsAlias)
		if id ~= nil then
			table.insert(tgList, i, tonumber(id))
			table.insert(ttlListedRange, i, id .. ' mm; ')
		end
	end
	ttlListedRange = tableTools.compressSparseArray(ttlListedRange)
	ttlListedRange = tableTools.removeDuplicates(ttlListedRange)
	tgList = tableTools.compressSparseArray(tgList)
	tgList = tableTools.removeDuplicates(tgList)
	return tgList
end
-----------------------------------------------------------------------------------
-- documentPostListStats -- build footer table, after list only
-----------------------------------------------------------------------------------
local function documentPostListStats(countTgList)
	-- Report data counters
	-- Data

	local retFoot = {}
	table.insert(retFoot, '\n*Sources')
	table.insert(retFoot, ':Data pages: [[:' .. dataPageName .. ']]')
	table.insert(retFoot, '*Data')
	table.insert(retFoot, ':Listed: ' .. table.concat(ttlListedRange, '') .. ' (' .. countTgList .. ' rows)')
	table.insert(retFoot, ":'''Entries''' (defined gauges, per unit): " .. ttlEntries)
	table.insert(retFoot, ":'''Gauges''' (defined gauges, per size): " .. countTgList)
	for i, stat in ipairs (ttlUnitCount) do
		table.insert(retFoot, ':' .. stat[2] .. ': ' .. stat[1])
	end

	table.insert(retFoot, ':Aliases (input options): ' .. ttlAliasCount)
	table.insert(retFoot, ':Named definitions (as output link; ' .. ttlAltNameCount .. '): ' .. table.concat(ttlAltName, '; '))

	table.insert(retFoot, ':Entries with an article link: ' .. ttlLinkCount)
	-- TODO table.insert(retFoot, '*Named gauges (named input)') -- todo
	-- Categories (content, maintenance)
	table.insert(retFoot, '*Categories')
	table.insert(retFoot, ':Content categories: ' .. ttlContentCatsCount)
	-- Size classes (narrow, broad, ..)
	table.insert(retFoot, '*Size classes')
	for i, stat in ipairs (ttlSizeClassCount) do
		if stat[2] ~= 0 then
			table.insert(retFoot, ':' .. stat[2] .. ' ' .. stat[3] .. ' (' .. stat[4] .. ' mentionings)')
		end
	end

	local anchor = tostring(mw.html.create():tag('span'):attr('id', 'Statistics'))
	-- help:using colors. Hue=190 (blue)
	local statTable = anchor .. '\n{| class="wikitable collapsible collapsed" style="background:#e6fbff; font-size:85%; width:100%;"'
	.. '\n|-'
	.. '\n! style="background:#ceecf2; width:100%;" | Track gauge data statistics'
	.. '\n|-'
	.. '\n|' .. table.concat(retFoot, '\n')
	.. '\n|}'
	
	return statTable
end
-----------------------------------------------------------------------------------
-- documentHeader
-----------------------------------------------------------------------------------
local function documentHeader(numberOfEntries, docTitle, docState)
	local docBgHeader = '#cef2e0' -- Green. See [[template:documentation]]

	-- Header row 1 (title)
	local pagetitle = mw.title.getCurrentTitle()
	urlPurgePage = pagetitle:fullUrl({action = 'purge'})
	urlPurgePage = '<span class="plainlinks purgelink nourlexpansion" title="Purge this page (update countings)">[' .. urlPurgePage .. ' (purge)]</span>'
	
	if docTitle == '' then
		docTitle = 'Track gauges' -- (' .. dataPageName .. ')' -- optional, sandbox here
	end
	docTitle = docTitle .. ' ' .. urlPurgePage
	if docState == '' then
		docState = 'uncollapsed'
	end
	
	-- Header row 2 (sort buttons, blank cells)
	local sortColHeaders = ''
	local sortClass = ''
	if (numberOfEntries or 0) > 1 then
		sortClass = 'sortable'
		local sortCell = '! style="background:' .. docBgHeader .. ';"'
		-- todo: 10 cols with bg color
		sortColHeaders = '\n|- style="background:' .. docBgHeader .. '; line-height:90%;"'
			.. '\n! &nbsp; || || || || || || || '
	end
	
	-- Header row 3 (column headers)
	local catMparent = modTrackGauge.catMentions(nil, 'Mentionings', 'show')
	
	--10 columns:
	local tableStyle = 'style="text-align:right; width:100%; font-size:85%;" '
	local retHdr = {}
		table.insert(retHdr, '\n{| class="wikitable collapsible ' .. docState .. ' ' .. sortClass .. '" ' .. tableStyle)
		table.insert(retHdr, '|-')
		table.insert(retHdr, '! colspan=10 style="background:' .. docBgHeader .. ';" | ' .. docTitle)
		table.insert(retHdr, '|-')
		table.insert(retHdr, '! style="background:' .. docBgHeader .. ';" | Gauge<br>(mm)')
		table.insert(retHdr, '! style="background:' .. docBgHeader .. ';" | Gauge<br>(ft,&nbsp;in)')
		table.insert(retHdr, '! style="background:' .. docBgHeader .. ';" | Alt<br>name')
		table.insert(retHdr, '! style="background:' .. docBgHeader .. ';" | Gauge<br>(inch)')
		table.insert(retHdr, '! style="background:' .. docBgHeader .. ';" | Def<br>unit')
		table.insert(retHdr, '! style="background:' .. docBgHeader .. '; width:8em;" | Aliases<br>(input&nbsp;options)')
		table.insert(retHdr, '! style="background:' .. docBgHeader .. ';" | Class<br>&nbsp;')
		table.insert(retHdr, '! style="background:' .. docBgHeader .. '; min-width:5em;" | Source<br>article')
		
	return table.concat(retHdr, '\n') .. sortColHeaders
end
-----------------------------------------------------------------------------------
-- documentFooter
-----------------------------------------------------------------------------------
local function documentFooter()
	return {'\n|}'}
end
-----------------------------------------------------------------------------------
-- documentFromIdToEntrySet -- from fromIdToEntrySet
-- From one id, make the set with all one-two-three-more entries (met, inp, variants)
-----------------------------------------------------------------------------------
local function documentFromIdToEntrySet(id, searchedAlias)
	local docBgColor = '#e6fff2' -- Green. See header bg color
	local rowSplit = '<div style="border-top:1px solid #ccc; height:1px;"></div>'
	
	-- From the size-id, build the set of existing entries (met, imp, and variants)
	local entry = {}
	local defType = 0
	-- data
	for i, tgEntry in ipairs(gaugeDataAll) do
		if id == tgEntry.id then
			if tgEntry.def1 == 'met' and entry[1] == nil then
				entry[1] = tgEntry
				defType = defType + 1
			elseif tgEntry.def1 == 'imp' and entry[2] == nil then
				entry[2] = tgEntry
				defType = defType + 2
			else
				entry[3 + tableTools.size(entry)] = tgEntry
			end
		end
	end
	entry = tableTools.compressSparseArray(entry)
	-- Entry set is now complete & clean
	-- Result: the entry table with entries present in /data,
	-- in sequence if present (1. met, 2. imp, any extra)
	-- (to build into a single row, maybe with split cells)
	
	--Build cell elements, then string row together.
	local inchCount = documentInchCount(entry[1])
	local datasortvalue = documentdatasortvalue(entry[1], 'met', 5)
	local aliasList = {}
	local tempEntryAltName = {}
	local entryAltName = {}
	local hasAltName = false
	for i, e in ipairs(entry) do
		local alis = {}
		for j, v in ipairs(e.aliases) do
			if tonumber(v) == nil then -- (plain numbers are not shown)
				table.insert(alis, tostring(v))
			end
		end
		for j, v in ipairs(alis) do
			if string.match(v, '^%d') == nil then -- textual so to italic.
				alis[j] = tostring(mw.html.create():tag('span'):wikitext(v):css('font-style', 'italic'))
			end
		end
		table.insert (aliasList, table.concat(alis, '; '))
		ttlAliasCount = ttlAliasCount + #alis
		-- process Alt name links
		if e.name or '' ~= '' then
			tempEntryAltName[i] = tostring(mw.html.create():tag('span'):wikitext(e.link):css('font-weight', 'bold'))
			table.insert(ttlAltName, e.id .. ': ' .. e.link)
			ttlAltNameCount = ttlAltNameCount + 1
			hasAltName = true
		end
	end
	if hasAltName then
		local text
		for i, v in ipairs(entry) do
			table.insert(entryAltName, i, tempEntryAltName[i] or '&nbsp;')
		end

	end
	local def = {} -- Definition unit code: 'met' or 'imp'
	local defText = {}
	for i, v in ipairs (entry) do
		table.insert(def, v.def1)
		if v.def1 == 'imp' then
			table.insert(defText, 'imp')
			ttlUnitCount[2][1] = ttlUnitCount[2][1] + 1
		elseif v.def1 == 'met' then
			table.insert(defText, 'met')
			ttlUnitCount[1][1] = ttlUnitCount[1][1] + 1
		end
	end
	if #entry >= 2 then
		if #entry == 2 and entry[1].def1 ~= entry[2].def1 then -- Regular pair: def in met and in imp
			ttlUnitCount[3][1] = ttlUnitCount[3][1] + 1
		else -- More than 2, or a double unit definition
			ttlUnitCount[4][1] = ttlUnitCount[4][1] .. ' ' .. id .. '&nbsp;mm (' .. #entry ..');'
		end
	end
	-- mm; ft in -- Measurement (number & unit; met and imp; anchor to here)
	local measure = {}
	local unitanchor = { '', '' }
	measure[1] = modTrackGauge.formatMet(entry[1])
	measure[2] = modTrackGauge.formatImp(entry[1]) -- both met and imp from entry[1]
	if modMath._mod(defType, 2) == 1 then
		measure[1] = tostring(mw.html.create():tag('span'):wikitext(measure[1]):css('font-weight', 'bold'))
		unitanchor[1] = anchor(entry[1], 'met')
	end
	if defType >= 2 then
		measure[2] = tostring(mw.html.create():tag('span'):wikitext(measure[2]):css('font-weight', 'bold'))
		unitanchor[2] = anchor(entry[1], 'imp')
	end
	-- Linked article
	local linkArticle = {}
	for i, e in ipairs(entry) do
		table.insert(linkArticle, e.pagename)
	end
	ttlLinkCount = ttlLinkCount + #linkArticle
	local eq
	if #linkArticle >= 2 then
		eq = true
		for i, v in ipairs(linkArticle) do
			if v ~= linkArticle[1] then
				eq = false
				break
			end
		end
		if eq == true then
			for i, v in ipairs(linkArticle) do
				if i > 1 then
					linkArticle[i] = nil
				end
			end
		end
	end
	for i, lp in ipairs(linkArticle) do
		local fmtLp = ''
		fmtLp = '[[' .. lp .. ']]'
		linkArticle[i] = tostring(mw.html.create():tag('span'):css('text-align', 'left'):wikitext(fmtLp))
	end
	-- catContent (content category for this alias). note: function p.catContent is a reduced code of this.
	-- can be hardcoded in the data, or build by size (pattern)
	local catContent = {}
	local catTitle
	local label
	local skipCheck = false
	for i, e in ipairs(entry) do
		if e.contentcat == '' then
			-- no cat; option to prevent expensive calls
			skipCheck = true
		elseif e.contentcat ~= nil then
			label = string.match(e.contentcat, '([%S]*)') or 'nomatch'
			table.insert(catContent,
				'[[:Category:' .. e.contentcat .. '|cat:' .. label .. '&nbsp;...]]')
		end
	end
	if #catContent >= 2 then
		eq = true
		for i, v in ipairs(catContent) do
			if v ~= catContent[1] then
				eq = false
				break
			end
		end
		if eq == true then
			for i, v in ipairs(catContent) do
				if i > 1 then
					catContent[i] = nil
				end
			end
		end
	end
	if #catContent == 0 and not skipCheck then
		local catCsuffix = ' gauge railways'
		if modMath._mod(defType, 2) == 1 then
			label = formatUnitPlaintext(entry[1], 'met')
			catTitle = mw.title.makeTitle(14, label .. catCsuffix)
			if catTitle.exists then
				table.insert(catContent,
					'[[:' .. catTitle.fullText .. '|cat:' .. noWrap(label) .. ']]')
			end
		end
		if defType >= 2 then
			label = formatUnitPlaintext(entry[1], 'imp', nil, true)
			catTitle = mw.title.makeTitle(14, label .. catCsuffix)
			if catTitle.exists then
				table.insert(catContent, '[[:' ..catTitle.fullText .. '|cat:' .. noWrap(label) .. ']]')
			end
		end
	end
	ttlContentCatsCount = ttlContentCatsCount + #catContent

	-- Mentions category
	local catMentions = modTrackGauge.catMentions(entry[1], "cat:mnt", 'show')
	local catCount = mw.site.stats.pagesInCategory(
	modTrackGauge.catMentions(entry[1], nil, 'pagename'), pages)
	ttlMentioningCatsCount = ttlMentioningCatsCount + 1 -- Exists
	ttlMentioningPageCount = ttlMentioningPageCount + catCount

	-- class: Counter SizeClass (narrow, broad, ...)
	local rgSizeClass = documentGaugeClass(entry[1], catCount)

	ttlEntries = ttlEntries + #entry
	sortCount  = mw.text.truncate('00000' .. tostring(catCount), -5, '')
	sortCount = '<span data-sort-value="' .. sortCount .. '">'
	catCount = sortCount .. catCount .. '&nbsp;P' .. '</span>' --(20190920: linter closing span added)

	-- Compose the size-id row with all cell values (10 columns)
	local row = {}
		table.insert(row, datasortvalue .. unitanchor[1] .. measure[1])
		table.insert(row, datasortvalue .. unitanchor[2] .. measure[2])
		table.insert(row, table.concat(entryAltName, rowSplit))
		table.insert(row, datasortvalue .. inchCount)
		table.insert(row, table.concat(defText, rowSplit))
		table.insert(row, table.concat(aliasList, rowSplit))
		table.insert(row, rgSizeClass)
		table.insert(row, table.concat(linkArticle, rowSplit))
		
	return '\n|- style="background:' .. docBgColor .. '; border-top:2px solid #aaa;" |'
		.. '\n|'
		.. table.concat(row, ' || ')
end
-----------------------------------------------------------------------------------
-- documentGauge -- Selfdocument gauge data (one, multiple, range, all)
-----------------------------------------------------------------------------------
function p.documentGauge(frame)
	local args = prepareArgs(frame)
	gaugeDataAll = mw.loadData(dataPageName)

		-- Init glolbal counters by table:
		ttlUnitCount =
			{
			[1] = {0, 'Entries defined metric'},
			[2] = {0, 'Entries defined imperial'},
			[3] = {0, 'Gauge sizes defined both metric and imperial'},
			[4] = {'', 'Gauge sizes with multiple entries in one unit'}
			}
		ttlSizeClassCount =
			{
			[1] = {'scaled', 0, 'scaled or model gauges', 0},
			[2] = {'min', 0, 'minimum gauges', 0},
			[3] = {'narrow', 0, 'narrow gauges', 0},
			[4] = {'s.g.', 0, 'standard gauge', 0},
			[5] = {'broad', 0, 'broad gauges', 0},
			[6] = {'unk', 0, 'unknown', 0}
			}

	local tgList = documentBuildTgList(args)
	-- Now loop through the prepared tgList[id] and add rows to result 	le
	-- One row contains all available entries for the id (met, imp, a third variant)
	local rowTGid = {}
	for i, numId in ipairs(tgList) do
		table.insert(rowTGid, documentFromIdToEntrySet(tostring(numId)))
	end
	-- Return args
	local retArgs = ''
	if args.docreturnargs == 'on' then
		retArgs = '\n' .. p.debugReturnArgs(frame)
	end
	-- Build statistics footer
	local retStats = ''
	if args.docstats == 'on' then
		retStats = documentPostListStats(#tgList)
	end
	-- Build up
	return documentHeader(#tgList, args.doctitle or '', args.docstate or '')
		.. table.concat(rowTGid, '')
		.. table.concat(documentFooter(), '')
		.. retStats
		.. retArgs
end
--------------------------------------------------------
-- doc
--------------------------------------------------------
function p.docFracAliases(frame)
	local args = prepareArgs(frame)
	gaugeDataAll = mw.loadData(dataPageName)

	local tgList = documentBuildTgList(args)
	local ttlHitCount =0
	local rowIMP = {}
	local fracAlias =''
	for i, id in ipairs(tgList) do
		for j, tgEntry in pairs(gaugeDataAll) do
			if nil and tostring(id) == '53.975' and tostring(id) == tgEntry.id then
				fracAlias = anchor(tgEntry, 'imp', 'there')
				fracAlias = mw.ustring.lower(mw.ustring.gsub(fracAlias, '[%s%,%#]', ''))
					table.insert(rowIMP, fracAlias .. '||' .. i .. '||' .. id ..
					'||' .. modTrackGauge.formatImp(tgEntry) .. ' || plus ' .. tgEntry.num)
			end
			if tostring(id) == tgEntry.id and tgEntry.def1 == 'imp' and tgEntry.num ~= nil then
				if tgEntry.ft ~= nil then
					ttlHitCount = ttlHitCount + 1
					fracAlias = anchor(tgEntry, 'imp', 'there')
					fracAlias = mw.ustring.lower(mw.ustring.gsub(fracAlias, '[%s%,%#]', ''))
					fracAlias = mw.ustring.gsub(fracAlias, '⁄', '/')

					table.insert(rowIMP, fracAlias .. '||' .. i .. '||' .. id ..
						'||' .. modTrackGauge.formatImp(tgEntry))
				
					fracAlias = tostring((tonumber((tgEntry.ft) or 0) * 12) + tonumber(tgEntry["in"] or 0)) .. tgEntry.num .. '/' .. tgEntry.den .. 'in'
					table.insert(rowIMP, fracAlias .. '||' .. i .. '||' .. id ..
						'||' .. modTrackGauge.formatImp(tgEntry))
				end
			end
		end
	end

--	return '\n|' .. ttlHitCount .. ' hits. ' .. #rowIMP

	return '\n\n|-\n\n|' .. table.concat(rowIMP, '\n\n|-\n\n|')
		
end
	
return p