Module:Iteration

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0 The module uses frequently the template {{=}} for title = "=" 0

This module contains the functions for different templates, solving their iteration problem

The MediaWiki template coding does not support the repetitive processing of a parameter set, which leads often to a very primitive and long chain of parameter checks in the kind of:

{{#if:{{{1|}}} | perform an action with parameter 1 }}
{{#if:{{{2|}}} | perform an action with parameter 2 }}
{{#if:{{{3|}}} | perform an action with parameter 3 }}
{{#if:{{{4|}}} | perform an action with parameter 4 }}
•••
•••
{{#if:{{{33|}}} perform an action with parameter 33 }}

with the disadvantage that such a construct will fail as soon as there comes a 34^th parm. I always thought that with Lua and its for loops this iterations should be possible, somehow. After long searching without any success and without an idea how to perform it, I asked at several forums and got finally from User:Trappist the monk the helping hint to solve it with a control structure like:

	local out = {}
	for i, v in ipairs (args) do
		table.insert (out, frame:expandTemplate{ title = title, args = v })
	end
	return table.concat (out)

The functions contained therein are from very simple, just one parameter to pass, to more complicated ones, where e.g. a pair of parameters needs kind of a flip-flop switch when always a tuple of e.g. an item and its correlated text needs to be passed.

When there are tuples, triples etc., the table.insert occurs, when the last element is processed; this performs problems when the last group is incomplete – it should be finished with empty values to trigger the table.insert. The check with table.maxn seems not to work correctly?

This problem is solved differently, for the function attribs with a primitive workaround.

Namespace lists

There are special lists for some namespaces:

Filelist - for items of the namespace 6 (File:)
Userlist - for items of the namespace 2 (User:)
Linklist - for items of the namespace 0 (main) — not yet
Templist - for items of the namespace 10 (Template:) — not yet
Cat-list - for items of the namespace 14 (Category:) — not yet
Mod-list - for items of the namespace ~~828~~ (Module:) — not yet

Filelist

File list templates

The three templates {{Ifim}}, {{Ifim1}} and {{Ifimt}} avoid to display the file itself as an |other version=.

There are currently five templates creating file lists with the function:filelist

{{Other versions}} a vertical list (without initial)
{{Filelist}} a horizontal list (without initial)
{{Derivative versions}} a vertical list
{{Derived from}} a vertical list
{{File}} a horizontal list

All these templates are autoreferencing, and the support also the |gallery= option.

Other file lists

The function:svglang creates a list of just file_names and language_codes, for:

Much more is created by the function:ownbased for the template:

{{Own based}}

which will handle in the majority of cases just one file, but can serve an unlimited number.

This list can be controlled by the user to be displayed either horizontally or vertically.

{{Attribs}}

The template works, whether there is a user assigned for a file, or one filename follows another.

{{Emoji}}

The template displays a line of SVG emojis; Unicode characters/emojis can be displayed with the function emodis or emotab.

Variable iterations

A very simple iteration, usable for everything, is performed by function:iterate

used by e.g. {{Image extracted}}, {{Image translated}},

More usable is the function:iteration for transclusions of a template with:

a number of positional parameters which can change at each transclusion, and
a number of positional parameters which are the same for all transclusions.

See template {{Iterate}}. The function:loop is used by {{Repeat}}.

`samefile` function

When the name of one of the files is the same as the first one, it is enough to reference it with its extension after a dot, e.g. just ".jpeg". The most standard extensions can be abbreviated, e.g. ".j" will be sufficient for ".jpg" (only for lower case!).

The function incrhx increments a hexadecimal number (parm 1) by a decimal number (parm 2).

Valid numbers are assumed, no checking occurs!

When parameter 2 is preceded by a minus, the first number is decremented by the second one.

Userlist

Userlist: {{Userlist}} with many formatting parameters

Linklist

Templist

Other iterations

Langlist:
Colorbox: {{ColorString}} and other color box templates
Legends : {{Legtab}} combines single {{Legend}}s
Tleparms: the metatemplate {{Tle}} displays the parameter usage of a template
Navigate: {{Navcat}} navigates through color categories
Showname: {{Showname}} helper template, for parameter tests
Emodis 0: {{Emoji}} displays (one or many) Unicode characters

The function emodis displays Unicode characters / emojis; it can care for newlines, while

The function emotab displays a table of files / emojis.

--  This module contains the functions for different templates, solving their iteration problems.


local p = {}


-- for Template:Ifim 
function p.ifim1 (frame) 
	local args = mw.getCurrentFrame(): getParent().args;
	local otab = {};
	local p1 = args.p1 or "";
	local p2 = args.p2 or "";
	local p3 = args.p3 or "";
	local p4 = args.p4 or "";
	local p5 = args.p5 or "";
	local fn = args.fn or "";
	for _, v in ipairs(args) do
		table.insert(otab, frame:expandTemplate{ title = "Ifim1", args = { v, p1, p2, p3, p4, p5, n= fn } });
	end
	return  table.concat (otab)
end

-- for Template:Ifimc 
function p.ifim2 (frame) 
	local args = mw.getCurrentFrame(): getParent().args;
	local otab = {};
	local p1 = args.p1 or "";
	local p2 = args.p2 or "";
	local p3 = args.p3 or "";
	local p4 = args.p4 or "";
	for _, v in ipairs(args) do
		table.insert(otab, frame:expandTemplate{ title = "Ifim2", args = { v, p1, p2, p3, p4, v } });
	end
	return  table.concat (otab)
end

-- for Template:Ifimt (param pairs)
function p.ifimt (frame) 
	local args = mw.getCurrentFrame(): getParent().args;
	local otab = {};
	local v1 = "";
	local p1 = args.p1 or "";
	local p2 = args.p2 or "";
	local p3 = args.p3 or "";
	local p4 = args.p4 or "";
	for _, v in ipairs(args) do
		if v1 == "" then   
			v1 = mw.text.trim( v );
		else
			table.insert(otab, frame:expandTemplate{ title = "Ifim2", args = { v1, p1, p2, p3, p4, v } });
			v1 = "";
		end
	end
	if v1 ~= "" then
		table.insert(otab, frame:expandTemplate{ title = "Ifim2", args = { v1, p1, p2, p3, p4, "" } });	-- last elem		
	end
	return  table.concat (otab)
end

-------------------------------------------------------

-- for Template:SVG lang
function p.svglang (frame) 
	local args = mw.getCurrentFrame(): getParent().args;
	local otab = {};
	local file = args.file or "";
	for _, v in ipairs(args) do
		table.insert(otab, frame:expandTemplate{ title = "Source thumb", args = { file, mw.text.trim(v) } });
	end
	return  table.concat (otab)
end

-- for Template:Derivative versions  and  for Template:Derived from (param pairs)
function p.derivates (frame) 
	local args = mw.getCurrentFrame(): getParent().args;
	local otab = {};
	local btab = {};
	local dis  = args.d  or args.dis  or args.display or "";
	local opt  = args.o  or args.opt  or args.option  or "";
	local prf  = args.p  or "<br><span style=color:#69F>✦ </span>"; -- 'list' item
	local by0  = args.by or "";
	if by0 == ":" then by0 = "" end;
	for i, v in ipairs(args) do
		btab [i] = args ["by" .. tostring( i )] or "."
	end
	for i, v in ipairs(args) do
		local pf = prf
		local by = by0
		if i == 1 then pf = "" end
		if btab[i] == "." then 
			by = by0               -- value missing 
 		elseif btab[i] == "-" then 
 			by =  ""               -- don't use by0
		else
			by = btab[i]           -- use specified
		end
		if v ~= '' then 
			table.insert(otab, frame:expandTemplate{ title = "F", args = {v, opt, dis, p= pf, by= by } });
		end
	end
 	return  table.concat (otab)
  end


-- for Template:Attribs  (param pairs)
function p.attribs (frame) 
	local args = mw.getCurrentFrame(): getParent().args;
	local otab = {};
	local ftab = {};
	local rtab = {}
	local rnum = 0;
	local tp   = args.type or "SVG";  -- needs check
	local un   = args.by or args.U or args.u or "";
	local f    = args.f or "";
	local tt   = args.t or args.f or "";
	local vx   = "";
	local ux   = "";
	local ft   = "";
	for i, v in ipairs(args) do
		ftab [i] = args ["f" .. tostring( i )] or ".";
--                                   table.maxnum (args) does not work
--                                   therefore the "rtab" workaround
		table.insert(rtab, args[i]);
		rnum = i
	end
--	                                 plus one item when odd number
	if  rnum % 2 ==  1 then
 		table.insert( rtab, "" ); -- empty user name, to get a pair
	end
--	
	for i, v in ipairs(rtab) do
		if vx == "" then     -- the 2nd 'v' can be empty
			vx = mw.text.trim( v );
		else
			ux = mw.text.trim( v );
			if ux == "" then ux = un end; -- does not work otherwise (?)
			if ftab[i/2] == "." then 
				ft = f;
			else
				ft = ftab[i/2]  
			end
			table.insert(otab, frame:expandTemplate{ title = "Attrib", args = {vx, ux, "-", tp, ux, ux, tt, ft } });
			vx = "";
		end
	end
	return  table.concat (otab)
end

-- for Template:Legend-table  (param pairs)
function p.legendt (frame) 
	local args = mw.getCurrentFrame(): getParent().args;
	local otab = {};
	local lg = args.lang or "";
	local v1 = ""
--                                    same problem when not a last pair
	for _, v in ipairs(args) do
		if v1 == "" then   
			v1 =  v;
		else
			table.insert(otab, frame:expandTemplate{ title = "Legend", args = { lang = lg, v1, v } });
			v1 = "";
		end	
	end
	if v1 ~= "" then
		table.insert(otab, frame:expandTemplate{ title = "Legend", args = { lang = lg, v1, "" } });	-- last elem
	end
	return  table.concat (otab)
end

-- for Template:ColorString (Igen/cbox    -    param pairs)
function p.colorbox (frame) 
	local args = mw.getCurrentFrame(): getParent().args;
	local otab = {};
	local lg = args.lang or "{{PAGELANGUAGE}}"; --
	local v1 = ""
	local p2 = ""
	for i, v in ipairs(args) do
		if i <= 2 then 
			p2 = v; 
		else	
			if v1 == "" then   
				v1 = mw.text.trim( v );
			else
				table.insert(otab, frame:expandTemplate{ title = "Igen/cbox", args = { v1, v, p2, lang = lg } });
				v1 = "";
			end
		end
	end
	if v1 ~= "" then
		table.insert(otab, frame:expandTemplate{ title = "Igen/cbox", args = { v1, "", p2, lang = lg } });	-- last elem		
	end
	return  table.concat (otab)
end


return p;