Module:Archive list

This module can be applied to any talk page or discussion archive, and will return links to all the numbered archives of that page or its parent page. By default the module uses the naming convention specified at w:WP:ARCHIVE, Talk:PAGENAME/Archive 1, with a capital A, a space before the number, and no leading zeros. This module should not usually be substituted – that way, the list of links will update itself whenever a new numbered archive is added.

This module can be used with Template:Tl to produce a box of numbered archive links without entering them all manually. To do this, use {{archive box|auto=yes}}.

The module is a replacement for the old Template:Tl template.

Usage

Main

The main function. Returns a list of archive links.

{{#invoke:Archive list|main
| root            = 
| links           = 
| nobr            = 
| prefix          = 
| prefixspace     = 
| linkprefix      = 
| linkprefixspace = 
| sep             = 
| linesep         = 
| start           = 
| max             = 
| auto            =
}}

Count

The count function. Returns the number of the most recent archive.

{{#invoke:Archive list|count
| root            = 
| prefix          = 
| prefixspace     = 
}}

Parameters

Valid parameters are:

• root = <root> - use this to specify a root other than that of the page from which the template is transcluded.
• links = # - the number of links to display per line. The default is 10.
• nobr = yes - set this to yes to remove all line breaks. This parameter cannot be used in conjunction with Template:Para.
• prefix = <prefix> - a custom prefix for the archives, without the number. The default is "Archive ".
• prefixspace = yes - adds a space between the prefix and the archive number for prefixes specified with Template:Para.
• linkprefix = <linkprefix> - a custom prefix for the display links, without the number. The default is blank. If auto=long, use 'none' to have it blank.
• prefixspace = yes - adds a space between the link prefix and the archive number for prefixes specified with Template:Para.
• sep = <sep> - the separator for archive links. The default value is the comma separator for the language set in your preferences: ", ". If this is set to either dot (⧼dot-separator⧽), pipe ( | ), comma (, ), or tpt-languages (⧼tpt-languages-separator⧽), then it uses that separator as specified for your default language. If it is any other value, that value is used as it is. If this module is called from #invoke then whitespace is stripped, but if called from another module then whitespace is preserved. This allows for other modules to use this module to create wikitables, etc. If called from #invoke, the whitespace problem can be worked around by using   (for spaces) and <br /> (for new lines).
• linesep = <linesep> - the separator for lines of archive links. The possible input values are the same as for the Template:Para parameter, and the default separator text is <br />. How often the value is displayed depends on the value of Template:Para.
• start = # - the archive number to start listing archives from. This must be smaller than the largest archive number, or Template:Para if it is specified.
• max = # - the largest archive number to list. This overrides the automatic detection of archive page numbers.
• auto = long - outputs as a table. Changes default value of links to 3 and linkprefix to 'Archive '.

Limitations

This module has no such limit to the number of archives it can detect. However, at very high numbers of archives this module might reach the expensive function call limit. On a page with no other templates that call expensive functions, this module should be able to output 400,000+ archive links. On pages with other templates that make expensive function calls, the module may fail sooner.

---

-- This module implements {{archive list}} in Lua, and adds a few
-- new features.

-- Process a numeric argument to make sure it is a positive
-- integer.
local function processNumArg( num )
    if num then
        num = tonumber( num )
        if type( num ) == 'number' then
            num = math.floor( num )
            if num >= 0 then
                return num
            end
        end
    end
    return nil
end

-- Checks whether a page exists, going through pcall
-- in case we are over the expensive function limit.
local function checkPageExists( title )
    if not title then
        error('No title passed to checkArchiveExists', 2)
    end
    local noError, titleObject = pcall(mw.title.new, title)
    if not noError then
        -- If we are over the expensive function limit then assume
        -- that the page doesn't exist.
        return false
    else
        if titleObject then
            return titleObject.exists
        else
            return false -- Return false if given a bad title.
        end
    end
end

-- Checks every nth archive to see if it exists, and returns the
-- number of the first archive that doesn't exist. It is
-- necessary to do this in batches because each check is an
-- expensive function call, and we want to avoid making too many
-- of them so as not to go over the expensive function limit.
local function checkArchives( prefix, n, start )
    local i = start
    local exists = true
    while exists do
        exists = checkPageExists( prefix .. tostring( i ) )
        if exists then
            i = i + n
        end
    end
    return i
end

-- Return the biggest archive number, using checkArchives()
-- and starting in intervals of 1000. This should get us a
-- maximum of 500,000 possible archives before we hit the
-- expensive function limit.
local function getBiggestArchiveNum( prefix, max )
    -- Return the value for max if it is specified.
    max = processNumArg( max )
    if max then
        return max
    end
    
    -- Otherwise, detect the largest archive number.
    local check1000 = checkArchives( prefix, 1000, 1 )
    if check1000 == 1 then
        return 0 -- Return 0 if no archives were found.
    end
    local check200 = checkArchives( prefix, 200, check1000 - 1000 )
    local check50 = checkArchives( prefix, 50, check200 - 200 )
    local check10 = checkArchives( prefix, 10, check50 - 50 )
    local check1 = checkArchives( prefix, 1, check10 - 10 )
    -- check1 is the first page that doesn't exist, so we want to
    -- subtract it by one to find the biggest existing archive.
    return check1 - 1
end

-- Get the archive link prefix (the title of the archive pages
-- minus the number).
local function getPrefix( root, prefix, prefixSpace )
    local ret = root or mw.title.getCurrentTitle().prefixedText
    ret = ret .. '/'
    if prefix then
        ret = ret .. prefix
        if prefixSpace == 'yes' then
            ret = ret .. ' '
        end
    else
        ret = ret .. 'Archive '
    end
    return ret
end

-- Get the number of archives to put on one line. Set to
-- math.huge if there should be no line breaks.
local function getLineNum( links, nobr, isLong )
    local linksToNum = tonumber( links )
    local lineNum
    if nobr == 'yes' or (links and not linksToNum) then
        lineNum = math.huge
    -- If links is a number, process it. Negative values and expressions
    -- such as links=8/2 produced some interesting values with the old
    -- template, but we will ignore those for simplicity.
    elseif type(linksToNum) == 'number' and linksToNum >= 0 then
        -- The old template rounded down decimals to the nearest integer.
        lineNum = math.floor( linksToNum )
        if lineNum == 0 then
            -- In the old template, values of links between 0 and 0.999
            -- suppressed line breaks.
            lineNum = math.huge
        end
    else
    	if isLong==true then
    		lineNum = 3 -- Default to 3 links on long
    	else
        	lineNum = 10 -- Default to 10 on short
        end
    end
    return lineNum
end

-- Gets the prefix to put before the archive links.
local function getLinkPrefix( prefix, space, isLong )
    -- Get the link prefix.
    local ret = ''
    if isLong==true then ---- Default of old template for long is 'Archive '
    	if type(prefix) == 'string' then
    		if prefix == 'none' then -- 'none' overrides to empty prefix
    			ret = ''
    		 else
    		 	ret = prefix
    		 	if space == 'yes' then
    		 		ret = ret .. ' '
    		 	end
		 	end
	 	else
	 		ret = 'Archive '
		end
	else --type is not long
		if type(prefix) == 'string' then
        	ret = prefix
        	if space == 'yes' then
        	    ret = ret .. ' '
        	end
    	end
    end
    return ret
end

-- Get the number to start listing archives from.
local function getStart( start )
    start = processNumArg( start )
    if start then
        return start
    else
        return 1
    end
end

-- Process the separator parameter.
local function getSeparator( sep )
    if sep and type(sep) == 'string' then
        if sep == 'dot' 
            or sep =='pipe'
            or sep == 'comma'
            or sep == 'tpt-languages' then
            return mw.message.new( sep .. '-separator' ):plain()
        else
            return sep
        end
    else
        return nil
    end
end

-- Generates the list of archive links. glargs.max must be either zero (for
-- no archives) or a positive integer value.
local function generateLinks( glargs )
    if type( glargs ) ~= 'table' or not glargs.max or not glargs.prefix then
        error('insufficient arguments passed to generateLinks', 2)
    end
    -- If there are no archives yet, return a message and a
    -- link to create Archive one.
    if glargs.max == 0 then
    	if glargs.isLong == true then
    		glargs.max = 1 -- One archive redlink is displayed for Long format
    	else -- Short error and a creat link is displayed for short
        	return 'no archives yet ([[' .. glargs.prefix .. '1|create]])'
        end
    end
    -- Return an html error if the start number is greater than the 
    -- maximum number.
    local start = glargs.start or 1
    if start > glargs.max then
        return '<span class="error">Start value "' 
            .. tostring( start ) 
            .. '" is greater than the most recent archive number "' 
            .. tostring( glargs.max ) 
            .. '".</span>'
    end
    local linkPrefix = glargs.linkPrefix or ''
        local lineNum = glargs.lineNum or 10
    local sep = '' -- Long default separator is cell elements, short is ', '
    local lineSep = '' -- Long default linebreak is row elements short is '\n'
    if glargs.isLong==true then 
    	sep = glargs.sep or ''
    	sep = sep .. '</td><td>'
    	lineSep = glargs.lineSep or ''
		lineSep = lineSep .. '</td></tr><tr><td>'
    else
    	sep = glargs.sep or mw.message.new( 'comma-separator' ):plain()
    	lineSep = glargs.lineSep or '<br />'
    end
    -- Generate the archive links.
    local lineCounter = 1 -- The counter to see whether we need a line break or not.
    local ret = {} -- A table containing the strings to be returned.
    if glargs.isLong == true then --Long version is a table
    	table.insert(ret, mw.getCurrentFrame():extensionTag('templatestyles', '', {src = 'Archive list/styles.css'}))
    	table.insert(ret, '<table class="archivelist-long"><tr><td>')
    end
    for archiveNum = start, glargs.max do
        local link = mw.ustring.format(
            '[[%s%d|%s%d]]',
            glargs.prefix, archiveNum, linkPrefix, archiveNum
        )
        table.insert( ret, link )
        -- If we don't need a new line, output a comma. We don't need
        -- a comma after the last link. 
        if lineCounter < lineNum and archiveNum < glargs.max then
            table.insert( ret, sep )
            lineCounter = lineCounter + 1
        -- Output new lines if needed. We don't need a new line after
        -- the last link.
        elseif lineCounter >= lineNum and archiveNum < glargs.max then
            table.insert( ret, lineSep )
            lineCounter = 1
        end
    end
    if glargs.isLong == true then --Long version is a table
    	table.insert(ret, "</td></tr></table>")
    end
    return table.concat( ret )
end

-- Determine if format should be long
local function findFormType( auto )
	if auto == nil or auto == '' then
		return false
	elseif auto == 'long' then
			return true
	else
		return false
	end
end

-- Get the archive data and pass it to generateLinks().
local function _main( args )
	local isLong = findFormType( args.auto )
    local prefix = getPrefix( args.root, args.prefix, args.prefixspace )
    local max = getBiggestArchiveNum( prefix, args.max )
    local lineNum = getLineNum( args.links, args.nobr, isLong )
    local linkPrefix = getLinkPrefix( args.linkprefix, args.linkprefixspace, isLong )
    local start = getStart( args.start )
    local sep = getSeparator( args.sep )
    local lineSep = getSeparator( args.linesep )
    local glargs = {
        start = start,
        max = max,
        prefix = prefix,
        linkPrefix = linkPrefix,
        isLong = isLong,
        sep = sep,
        lineNum = lineNum,
        lineSep = lineSep
    }
    return generateLinks( glargs )
end

-- A wrapper function to make getBiggestArchiveNum() available from
-- #invoke.
local function _count( args )
    local prefix = getPrefix( args.root, args.prefix, args.prefixspace )
    local archiveMax = getBiggestArchiveNum( prefix )
    return archiveMax
end

function makeWrapper( func )
    return function( frame )
        -- If we are being called from #invoke, get the args from #invoke
        -- if they exist, or else get the arguments passed to the parent
        -- frame. Otherwise, assume the arguments are being passed directly
        -- in from another module or from the debug console.
        local origArgs
        if frame == mw.getCurrentFrame() then
            origArgs = frame:getParent().args
            for k, v in pairs( frame.args ) do
                origArgs = frame.args
                break
            end
        else
            origArgs = frame
        end
        
        -- Ignore blank values for parameters other than "links",
        -- which functions differently depending on whether it is
        -- blank or absent.
        local args = {}
        for k, v in pairs( origArgs ) do
            if k == 'links' or v ~= '' then
                args[k] = v
            end
        end
        
        return func( args )
    end
end

return {
    main = makeWrapper( _main ),
    count = makeWrapper( _count )
}