Module:SortName

This module returns a string in a format suitable as a category sortkey, per WP:NAMESORT.

Input

The module accepts a string as the first and only unnamed parameter, but is meant to be used with no parameter, in which case the title of the calling page is used.

Usage

This module should be subst'd for use in template parameters that accept a sortkey or in the {{DEFAULTSORT}} variable.

• No input (sorts the pages title): {{subst:#invoke:SortName|sortname}}
• With input: {{subst:#invoke:SortName|sortname|input string}}

---

local p = {}

function p.sortname(frame)
    local currentpage = mw.title.getCurrentTitle()
    local pagetitle = frame.args[1] or currentpage.text
    local langvar = mw.language.getContentLanguage()
    local text1 = ''
    local text2 = ''
    local parts = { 'de','De','von','Von','du','Du','del','Del','zu','Zu','di','Di','van','Van','na','Na','le','Le','de\'','De\'' }
    local partmatch = false
    if string.find( pagetitle, ' ' ) ~= nil then
        pagetitle = string.gsub( string.gsub( string.gsub( pagetitle, '%b()', '' ), ' +', ' '), ' $', '' )
        if string.find( pagetitle, '^List of ' ) ~= nil then
            pagetitle = langvar:ucfirst( string.gsub( pagetitle, '^List of ', '', 1 ) )
        elseif string.find( pagetitle, '^The ' ) ~= nil then
            pagetitle = string.gsub( pagetitle, '^The ', '' ) .. ', The'
        else
            pagetitle = string.gsub( pagetitle, ',.*$', '' )
            pagetitle = string.gsub( pagetitle, ' of .*$', '' )
            for i in ipairs( parts ) do
                if string.find( pagetitle, ' ' .. parts[i] .. ' ' ) ~= nil then
                    text1 = string.sub( pagetitle, string.find( pagetitle, ' ' .. parts[i] .. ' ' ) + 1, #pagetitle )
                    text2 = string.sub( pagetitle, 0, string.find( pagetitle, ' ' .. parts[i] .. ' ' ) - 1 )
                    pagetitle = text1 .. ', ' .. text2
                    partmatch = true
                    break
                end
            end
            if not partmatch and string.find( pagetitle, ' ' ) ~= nil then
                text1 = string.sub( pagetitle, string.find( pagetitle, ' [^ ]*$' ) + 1, #pagetitle )
                text2 = string.sub( pagetitle, 0, string.find( pagetitle, ' [^ ]*$' ) - 1 )
                local romannumeral = roman_to_numeral(text1)
                if romannumeral == -1 then
                    pagetitle = text1 .. ', ' .. text2
                else
                    if string.find( text2, ' ' ) == nil then
                        pagetitle = text2 .. ' ' .. romannumeral
                    else
                        text1 = string.sub( text2, string.find( text2, ' [^ ]*$' ) + 1, #text2 )
                        text2 = string.sub( text2, 0, string.find( text2, ' [^ ]*$' ) - 1 )
                        pagetitle = text1 .. ' ' .. romannumeral .. ', ' .. text2
                    end
                end
            end
        end
    end
    return pagetitle
end

-- the following table and roman_to_numeral function came from Module:ConvertNumeric, created by User:Dcoetzee
roman_numerals = {
    I = 1,
    V = 5,
    X = 10,
    L = 50,
    C = 100,
    D = 500,
    M = 1000
}
 
-- Converts a given valid roman numeral (and some invalid roman numerals) to a number. Returns -1, errorstring on error
function roman_to_numeral(roman)
    if type(roman) ~= "string" then return -1, "roman numeral not a string" end
    local rev = roman:reverse()
    local raising = true
    local last = 0
    local result = 0
    for i = 1, #rev do
        local c = rev:sub(i, i)
        local next = roman_numerals[c]
        if next == nil then return -1, "roman numeral contains illegal character " .. c end
        if next > last then
            result = result + next
            raising = true
        elseif next < last then
            result = result - next
            raising = false
        elseif raising then
            result = result + next
        else
            result = result - next
        end
        last = next
    end
    return result
end
 
return p