Module:Portal navigation

 require('strict')
 localp={}
 localgetArgs=require('Module:Arguments').getArgs
 localyesno=require("Module:Yesno")

 localfunctionconverttolinearrgb(c)
 c=tonumber(c,16)
 c=c/255.0
 ifc<=0.03928then
 c=c/12.92321-- Correct constant from sRGB standard
 else
 c=((c+0.055)/1.055)^2.4
 end

 returnc
 end

 localfunctionluminance(color)
 -- The text color in the header is automatically chosen based on the best contrast
 -- https://stackoverflow.com/questions/3942878/how-to-decide-font-color-in-white-or-black-depending-on-background-color

 localrgb=string.gsub(color,'#','')
 rgb=mw.text.split(rgb,'')
 localr,g,b
 if#rgb==6then
 r=rgb[1]..rgb[2]
 g=rgb[3]..rgb[4]
 b=rgb[5]..rgb[6]
 elseif#rgb==3then
 r=rgb[1]..rgb[1]
 g=rgb[2]..rgb[2]
 b=rgb[3]..rgb[3]
 end
 r=converttolinearrgb(r)
 g=converttolinearrgb(g)
 b=converttolinearrgb(b)

 return0.2126*r+0.7152*g+0.0722*b
 end

 localfunctiongenerate_header(root,args)
 localheader=root:tag('div')
 header:css('font-size','1.6875em')
 header:css('border-radius','2px')
 header:css('font-weight','bold')
 header:css('padding','0.25em')
 header:css('background',args.themecolor)
 header:css('color',luminance(args.themecolor)>0.1791and'#000'or'#fff')
 header:cssText(args.headerstyle)
 header:wikitext(args.portalname)
 ifargs.portaliconthen
 localspan=header:tag('span')
 span:css('padding','0.3em')
 span:css('display','inline-block')
 span:css('margin-right','0.5em')
 span:wikitext(portalicon)
 end
 returnheader
 end

 localfunctiongenerate_tab(body,index,args)
 localcontainer=body:tag('li')
 container:css('display','inline-block')
 container:css('position','relative')
 container:css('vertical-align','top')
 container:css('margin','0')

 -- Create the tab itself

 localentry=container:tag('span')
 entry:css('display','inline-block')
 entry:css('margin','1em')
 entry:css('padding-bottom','0.5em')
 entry:css('font-weight','bold')
 ifindex==args.activethen
 ifnotargs.subtabs[index]orargs.hidesubnavthen
 entry:css('border-bottom','0.3em solid '..args.themecolor)
 else
 entry:css('margin-bottom','0')
 end
 else
 entry:css('border-bottom','0.3em solid #c8ccd1')
 end

 ifargs.tabsicons[index]then
 localicon=entry:tag('span')
 icon:css('margin-right','0.75em')
 icon:wikitext(args.tabsicons[index])
 end
 entry:wikitext(args.tabs[index])

 -- If the tab is active, show the subnav if there is any

 ifindex==args.activeandargs.subtabs[index]andnotargs.hidesubnavthen
 localsubnav=container:tag('ul')
 subnav:css('font-size','95%')
 subnav:css('margin','0 1em')
 subnav:css('padding','1.125em 0')
 localborderColor='0.35em solid '..args.themecolor
 subnav:css('border-top',borderColor)
 subnav:css('border-bottom',borderColor)
 subnav:css('list-style','none')
 for_,subpagelinkinipairs(args.subtabs[index])do
 locallink=subnav:tag('li')
 link:css('margin','0')
 link:wikitext(subpagelink)
 end
 end
 returncontainer
 end

 functionp._render(args)
 localtabs={}
 localsubtabs={}
 localtabsicons={}
 -- Default values
 args.portalname=args.portalnameor'Portal'
 args.themecolor=args.themecoloror'#54595d'
 for_,keyinipairs({'wrc','hidenav','hidesubnav'})do
 args[key]=yesno(args[key])
 end
 args.active=tonumber(args.active)
 forkey,valueinpairs(args)do
 localid=tonumber(mw.ustring.match(key,'^tab(%d+)$'))
 ifidthen
 tabs[id]=value
 else
 id=tonumber(mw.ustring.match(key,'^icon(%d+)$'))
 ifidthen
 tabsicons[id]=value
 else
 localprimetab,subtab=mw.ustring.match(key,'^subtab(%d+)-(%d+)$')
 ifprimetabandsubtabthen
 primetab=tonumber(primetab)
 subtab=tonumber(subtab)
 ifnotsubtabs[primetab]then
 subtabs[primetab]={}
 end
 subtabs[primetab][subtab]=value
 end
 end
 end
 end
 args.tabs=tabs
 args.subtabs=subtabs
 args.tabsicons=tabsicons

 -- Constructing header

 localroot=mw.html.create('div')
 ifargs.wrcthen
 localbadgeargs={}
 ifwrcadditionalthen
 badgeargs['additional']=args.wrcadditional
 end

 root:wikitext(frame:expandTemplate{
 title='Wikimedia Resource Center badge',
 args=badgeargs})
 end
 generate_header(root,args)

 -- Constructing the rest

 ifnotargs.hidenavthen
 localbody=root:tag('ul')
 body:css('font-size','1.125em')
 body:css('list-style','none')
 body:css('margin','0 0 1.125em 0')

 localtabindex={}
 forindex,_inpairs(tabs)do
 table.insert(tabindex,index)
 end
 table.sort(tabindex)

 for_,indexinipairs(tabindex)do
 generate_tab(body,index,args)
 end
 end
 localclear=root:tag('div')
 clear:css('clear','both')
 returntostring(root)
 end

 functionp.render(frame)
 localargs=getArgs(frame)
 returnp._render(args)
 end

 returnp