Module:Iteration/doc

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^nd 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

1. {{Other versions}} a vertical list (without initial)
2. {{Filelist}} a horizontal list (without initial)
3. {{Derivative versions}} a vertical list
4. {{Derived from}} a vertical list
5. {{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:

6. {{Svg lang}}
7. {{Lang gallery}}
8. {{Multilingual SVG diagrams}}

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

9. {{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.

10. {{Attribs}}

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

11. {{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

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.