Module:Str rightc

This module is rated as ready for general use. It has reached a mature state, is considered relatively stable and bug-free, and may be used wherever appropriate. It can be mentioned on help pages and other Wikipedia resources as an option for new users. To minimise server load and avoid disruptive output, improvements should be developed through sandbox testing rather than repeated trial-and-error editing.

This Lua module is used in system messages, and on approximately 4,200 pages.
Changes to it can cause immediate changes to the Elite Dangerous Wiki user interface.
To avoid major disruption, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Please discuss changes on the talk page before implementing them.

This implements: {{str rightc}} but if |notemplate= is set to a non-empty string, arguments from the invocation can be used.

Usage

{{#invoke:str rightc|rightc|notemplate=1|string|count}}

{{#invoke:str rightc|rightc|notemplate=1|string|count|result if empty}}

Gives a substring of length count characters from the right-side end of the string, or, if provided, returns result if empty when string is empty.

Examples

{{#invoke:str rightc|rightc|notemplate=1 |Lorem ipsum dolor sit amet |10}} → r sit amet
{{#invoke:str rightc|rightc|notemplate=1 |Lorem ipsum dolor sit amet |1}} → t
{{#invoke:str rightc|rightc|notemplate=1 |Lorem ipsum dolor sit amet |0}} →
{{#invoke:str rightc|rightc|notemplate=1 | |1 |string is empty}} → string is empty
{{#invoke:str rightc|rightc|notemplate=1 |123456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789-1 |99}} → 3456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789-1

require[[strict]]
local p = {}

function p._rightc(str, count, empty)
	str = mw.text.trim(str or '')
	if '' == str then
		return mw.text.trim(empty or '')
	end
	count = tonumber(count or '')
	if nil == count then
		return str
	end
	if count <= 0 then
		return ''
	end
	return mw.ustring.sub(str, -count)
end

function p.rightc(frame)
	local args = frame.args
	if '' == (args.notemplate or '') then
		args = frame:getParent().args
	end
	return p._rightc(args[1], args[2], args[3])
end

return p