Module:If elseif

Module documentation[view] [edit] [history] [purge]

Implements {{If elseif}}. Tests a series of expressions, which are evaluated either as blank/noblank or, if |yesno= is set, using {{Yesno}}. Functionally equivalent to a if...elseif...elseif...else string butore efficient than nesting {{#if:}} parser functions from a post-expand include size standpoint.

Usage

{{#if:test 1|value 1|{{#if:test 2|value 2|{{#if:...|default value}}}}}} can be replaced with

{{#invoke:if elseif||test 1|value 1|test 2|value 2|...|default value}} or

{{#invoke:if elseif||if1 = test 1|then1 = value 1|if2 = test 2|then2 = value 2|...|else = default value}}

Examples

• "{{#invoke:if elseif||{{{empty1|}}}|1|{{{empty2|}}}|2|all empty}}" → "all empty"

• "{{#invoke:if elseif||if1={{{empty1|}}}|then1=1|if2={{{notempty2|somevalue}}}|then2=2|else=all empty}}" → "2"

• "{{#invoke:if elseif||{{#expr:1<0}}|1<0|{{#expr:4<0}}|4<0|{{#expr:-1<0}}|-1<0|{{#expr:-2<0}}|-2<0|None are true|yesno=true}}" → "-1<0"
  • Note the use of |yesno=true. Without it, the module returns "1<0" since #expr returns 0 when the statement is false, which is not blank.

The above documentation is transcluded from Module:If elseif/doc. (edit | history)
Editors can experiment in this module's sandbox (edit | diff) and testcases (create) pages.
Subpages of this module.

p = {}

local yesno = require('Module:Yesno')

p['_elseif'] = function(args)
	local n = 1
	repeat
		local ifval, thenval
		if args[n] then
			if args[n+1] then
				ifval, thenval = args[n], args[n+1]
				n = n + 2
			else
				return args[n]
			end
		elseif args['if' .. n] and args['then' .. n] then
			ifval, thenval = args['if' .. n], args['then' .. n]
			n = n + 1
		else
			return args['else'] or ""
		end
		if yesno(args.yesno) then
			if yesno(ifval) then return thenval end
		elseif mw.text.trim(ifval or '') ~= '' then
			return thenval
		end
	until false
end

p['elseif'] = function(frame)
	local args = require('Module:Arguments').getArgs(frame, {trim = false, removeBlanks = false})
	return p['_elseif'](args)
end

p[''] = p['elseif']

return p