Module:Track gauge

 -- This module implements the {{Track gauge}} template.
 -- Data is in Module:Track gauge/data
 localp={}
 localgaugeDataAll=nil
 localdataPageName='Module:Track gauge/data'-- set /data/sandbox here to test data/sandbox
 -----------------------------------------------------------------------------------
 -- prepareArgs -- Normalise Arguments coming from an #invoke or from a module
 -----------------------------------------------------------------------------------
 localfunctionprepareArgs(frame)
 localorigArgs
 ifframe==mw.getCurrentFrame()then
 origArgs=frame:getParent().args
 fork,vinpairs(frame.args)do
 origArgs=frame.args
 break
 end
 else
 origArgs=frame
 end
 localargs={}
 -- searchAlias is the cleaned value of args[1]. args[1] is kept as rawInput for error message
 localsearchAlias=''
 localrawDisp
 fork,vinpairs(origArgs)do
 iftonumber(k)==nilthen-- Named argment
 ifk=='disp'then
 rawDisp=v-- Keep raw disp input to pass through plain (wiki)text
 args[k]=mw.ustring.lower(v)
 elseifk=='first'then
 v=mw.ustring.lower(v)
 ifv=='met'orv=='metric'then
 v='met'
 elseifv=='imp'orv=='imperial'then
 v='imp'
 elsek='trashparam_first'end
 args[k]=v
 elseifk=='nowrap'ork=='wrap'then-- wrap=y deprecated; reading: nowrap=off
 v=mw.ustring.lower(v)
 ifv==''orv=='off'orv=='on'orv=='all'then
 elseifv=='inline'or(k=='wrap'andv=='y')then
 v='off'
 elsev=''end
 args['nowrap']=v
 else
 args[k]=mw.ustring.lower(v)
 end
 else
 args[k]=v-- Keep rawInput in [1] for error message
 ifk==1then
 -- Unnamed argument, the alias to be searched
 -- Cleanup
 searchAlias=p.normaliseAliasInput(v)
 end
 end
 end
 args['searchAlias']=searchAlias
 ifrawDispthenargs['rawDisp']=rawDispend
 returnargs
 end
 -----------------------------------------------------------------------------------
 -- normaliseAliasInput
 -----------------------------------------------------------------------------------
 functionp.normaliseAliasInput(aliasIn)
 locala
 a=mw.ustring.lower(mw.ustring.gsub(aliasIn,'[%s%,]',''))
 a=mw.ustring.gsub(a,' ','')
 a=mw.ustring.gsub(a,'gauge$','')
 a=mw.ustring.gsub(a,"'","ft")
 a=mw.ustring.gsub(a,'"','in')
 a=mw.ustring.gsub(a,'⁄','/')
 a=mw.ustring.gsub(a,'⁄','/')
 returna
 end
 -----------------------------------------------------------------------------------
 -- debugReturnArgs -- Debug function.
 -----------------------------------------------------------------------------------
 functionp.debugReturnArgs(frame)
 localargs=prepareArgs(frame)
 localretArgs={}
 fork,ainpairs(args)do
 table.insert(retArgs,k..'='..a)
 end
 return'Args: '..table.concat(retArgs,'; ')
 end
 -----------------------------------------------------------------------------------
 -- getTrackGaugeEntry -- Find entry data for a single gauge (alias)
 -----------------------------------------------------------------------------------
 functionp.getTrackGaugeEntry(searchAlias)
 gaugeDataAll=mw.loadData(dataPageName)
 ifsearchAlias==''then
 returnnil
 end
 localtgEntry=nil
 fori,tgEntryinipairs(gaugeDataAll)do
 forj,aliasinipairs(tgEntry.aliases)do
 ifalias==searchAliasthen
 returntgEntry
 end
 end
 end
 end
 -----------------------------------------------------------------------------------
 -- noWrap -- Add span tags to prevent a string from wrapping.
 -----------------------------------------------------------------------------------
 localfunctionnoWrap(s)
 returnmw.ustring.format('<span class="nowrap">%s</span>',s)
 end
 -----------------------------------------------------------------------------------
 -- frac -- A slimmed-down version of the {{frac}} template (a nowrap is to be added with the unit)
 -----------------------------------------------------------------------------------
 localfunctionfrac(whole,num,den)
 -- normally would do the TemplateStyles expansion here, but instead we do
 -- it at the callsite because of [[:phab:T200704]]
 returnmw.ustring.format(
 '<span class="frac">%s<span class="num">%s</span>&frasl;<span class="den">%s</span></span>',
 wholeand(whole..'<span class="sr-only">+</span>')or'',
 num,
 den
 )
 end
 -----------------------------------------------------------------------------------
 -- catMentions -- Wikicode for "article mentions gauge" categories
 -----------------------------------------------------------------------------------
 functionp.catMentions(tgEntry,sortlabel,doReturn)
 localns='Category:'
 localcat

 iftgEntry==nilthen
 -- Parent, the container cat
 cat='Articles that mention a specific track gauge'
 else
 cat='Articles that mention track gauge '..tgEntry.id..' mm'
 end
 -- Argument 'label' can be used to add a catsort. Catsort is not used (as of 20 May 2014)
 ifsortlabel~=nilthen
 sortlabel='|'..sortlabel
 else
 sortlabel=''
 end
 ifdoReturn~=nilthen
 ifdoReturn=='fullpagename'then
 returnns..cat
 elseifdoReturn=='pagename'then-- plaintext, no namespace
 returncat
 elseifdoReturn=='show'then-- colontrick
 return'[[:'..ns..cat..sortlabel..']]'
 else-- unknown arg value
 returnns..cat
 end
 else-- Returns straight categorisation (wikitext)
 return'[['..ns..cat..sortlabel..']]'
 end
 end
 -----------------------------------------------------------------------------------
 -- formatImp -- Formats imperial units size into a single text element
 -----------------------------------------------------------------------------------
 functionp.formatImp(tgEntry,measurementToLink,setNowrap,addUnitlink)
 localret={}
 localft=tgEntry.ft
 ifftthen
 localftlink=addUnitlinkandmeasurementToLink~='imp'and'[[Foot (unit)|ft]]'or'ft'

 table.insert(ret,mw.ustring.format('%s&nbsp;%s',ft,ftlink))
 end
 localinches=tgEntry['in']
 localnum=tgEntry.num
 localden=tgEntry.den
 localhas_fraction=numandden
 ifinchesandnotnumandnotdenthen

 table.insert(ret,inches)
 elseifhas_fractionthen
 table.insert(ret,frac(inches,num,den))
 end
 ifinchesornumanddenthen
 localincheslink=addUnitlinkandmeasurementToLink~='imp'and'[[inch|in]]'or'in'
 table.insert(ret,incheslink)
 end
 localgaugeSize
 ifsetNowrapthen
 gaugeSize=noWrap(table.concat(ret,'&nbsp;'))
 else
 gaugeSize=table.concat(ret,'&nbsp;')
 end
 -- we have do this here to work around [[phab:T200704]]
 localtemplatestyles
 ifhas_fractionthen
 templatestyles=mw.getCurrentFrame():extensionTag{
 name='templatestyles',args={src='Fraction/styles.css'}
 }
 else
 templatestyles=''
 end

 ifmeasurementToLink=='imp'andtgEntry.pagename~=nilthen
 returnmw.ustring.format(
 '%s[[%s|%s]]',
 templatestyles,
 tgEntry.pagename,
 gaugeSize
 )
 else
 returntemplatestyles..gaugeSize
 end
 end
 -----------------------------------------------------------------------------------
 -- formatMet -- Formats metric measurements into a single formatted text element. Public for autodocument
 -----------------------------------------------------------------------------------
 functionp.formatMet(tgEntry,measurementToLink,setNowrap,addUnitlink,removeComma)
 localm=tgEntry.m
 localgaugeSize
 ifmthen
 localmUnit=addUnitlinkandmeasurementToLink~='met'and'[[metre|m]]'or'm'
 gaugeSize=mw.ustring.format('%s&nbsp;%s',m,mUnit)
 else
 localmm=tgEntry.mm
 mm=tonumber(mm)
 ifmmthen
 mm=mw.getContentLanguage():formatNum(mm)
 ifremoveCommathen
 mm=string.gsub(mm,",","")
 end
 end
 localmmUnit=addUnitlinkandmeasurementToLink~='met'and'[[millimetre|mm]]'or'mm'
 gaugeSize=mw.ustring.format('%s&nbsp;%s',mm,mmUnit)
 end
 ifsetNowrapthen
 gaugeSize=noWrap(gaugeSize)
 end
 ifmeasurementToLink=='met'andtgEntry.pagename~=nilthen
 returnmw.ustring.format('[[%s|%s]]',tgEntry.pagename,gaugeSize)
 else
 returngaugeSize
 end
 end
 -----------------------------------------------------------------------------------
 -- formatAltName
 -----------------------------------------------------------------------------------
 functionformatAltName(tgEntry,addGaugeName,addGaugeNameLink,disp,setNowrap,engvar)
 -- Assumed: at least one to add is true.
 iftgEntry.name==nilthen
 -- Not checked: link does exist alone
 return''
 end
 localretAlt={}
 ifdisp=='br'then
 table.insert(retAlt,'<br />')
 else
 table.insert(retAlt,' ')
 end
 ifsetNowrapthen
 table.insert(retAlt,'<span class="nowrap">')
 end
 ifaddGaugeNameLinkthen
 ifengvar=='en-us'then
 -- Current implementations (2016): metER for metRE (1000-met, 1009-met)
 table.insert(retAlt,tgEntry.en_US_linkortgEntry.linkortgEntry.name)
 else
 table.insert(retAlt,tgEntry.linkortgEntry.name)
 end
 else-- so must be unlinked .name to add
 ifengvar=='en-us'then
 -- Current implementations (2016): metER for metRE (1000-met, 1009-met)
 table.insert(retAlt,tgEntry.en_US_nameortgEntry.name)
 else
 table.insert(retAlt,tgEntry.name)
 end
 end
 ifsetNowrapthen--close tag
 table.insert(retAlt,'</span>')
 end
 returntable.concat(retAlt,'')
 end
 -----------------------------------------------------------------------------------
 -- main -- The basic module
 -----------------------------------------------------------------------------------
 functionp.main(frame)
 -- In general: the tgEntry object (from TG/data) is passed to the functions, while arguments are processed here.
 localtitle=mw.title.getCurrentTitle()
 localargs=prepareArgs(frame)
 localtgEntry=p.getTrackGaugeEntry(args.searchAlias)

 -- Categorise & preview warning when no track gauge definition was found.
 iftgEntry==nilthen
 localinput=args[1]or''
 localerrorTail=require('Module:If preview')._warning({
 'Track gauge '..
 input..
 ' not in [[:Template:Track_gauge#List_of_defined_track_gauges|List of defined track gauges]] ([[Template talk:Track gauge|talk]]).'
 })

 iftitle:inNamespaces(0,14)then-- mainspace and category space
 errorTail=errorTail.."[[Category:Articles using Template:Track gauge with unrecognized input]]"
 end
 returninput..errorTail
 end

 -- Check and set args & tgEntry props: disp, first, nowrap, first
 localdisp=args.dispor''
 localfirst=args.firstortgEntry.def1
 localunitlink=args.unitlinkor''
 localcomma=args.commaor''
 localnowrap=args.nowrapor''
 localsetNowrapElement=(nowrap==''ornowrap=='off')-- To prevent nested nowrap tags
 localmeasurementToLink
 ifargs.lk=='on'then
 ifdisp=='1'then
 measurementToLink=first-- Can make metric text links to the imp linked page
 else
 measurementToLink=tgEntry.def1-- When first=swapped, this could link 2nd measure.
 end
 end
 -- String the text elements together (compose the return table)
 localret={}
 -- nowrap opening tag
 ifnowrap=='all'ornowrap=='on'then
 table.insert(ret,'<span class="nowrap">')
 end
 -- First measure
 iffirst=='met'then
 table.insert(ret,
 p.formatMet(tgEntry,measurementToLink,setNowrapElement,unitlink=='on',comma=='off'))
 else
 table.insert(ret,
 p.formatImp(tgEntry,measurementToLink,setNowrapElement,unitlink=='on',comma=='off'))
 end
 -- The joint and the second measure
 ifdisp=='1'then
 else
 localjoinText=''
 localcloseDisp=''
 ifdisp=='s'ordisp=='/'then
 joinText='&nbsp;/ '--spaces
 elseifdisp=='br'then
 joinText='<br />('
 closeDisp=')'
 elseifdisp=='['ordisp=='[]'then
 joinText=' ['
 closeDisp=']'
 elseifdisp~=''then-- Is anytext
 joinText=' '..args['rawDisp']..' '
 else
 joinText=' ('
 closeDisp=')'
 end
 table.insert(ret,joinText)
 iffirst~='met'then
 table.insert(ret,
 p.formatMet(tgEntry,measurementToLink,setNowrapElement,unitlink=='on',comma=='off'))
 else
 table.insert(ret,
 p.formatImp(tgEntry,measurementToLink,setNowrapElement,unitlink=='on'))
 end
 table.insert(ret,closeDisp)-- Could be ''
 end
 ifnowrap=='on'then-- Closing tag
 table.insert(ret,'</span>')
 end
 -- Alternative name
 ifargs.al=='on'orargs.allk=='on'then
 localsetNowrapAltname=(nowrap==''ornowrap=='on')-- Logic applied to prevent nested nowrap tags
 table.insert(ret,formatAltName(tgEntry,args.al=='on',args.allk=='on',disp,setNowrapAltname,args.engvar))
 end
 -- Closing nowrap tag
 ifnowrap=='all'then
 table.insert(ret,'</span>')
 end

 -- Category mentionings (maintenance)
 ifargs.addcator''=='no'then
 -- No categorization
 elseiftitle:inNamespaces(0)then
 -- switched off per [[Wikipedia:Categories_for_discussion/Log/2016_December_6#Category:Articles_that_mention_a_specific_track_gauge]]
 -- 2016年12月19日
 -- table.insert(ret, p.catMentions(tgEntry))
 end

 -- Now sting the table together
 returntable.concat(ret,'')
 end

 returnp
 --20161219: maintenance categorisation switched off per CfD
 --20170602: fix bug, show name when al=on
 --20180708: show preview warning when gauge is not in list
 --20190124: with disp=/ (slash) value separator: surround by spaces
 --20210304: add option comma=off (mm only)