Module:Era

Module implementing the Wikisource-specific categorisation of years into literary "eras": Ancient, Medieval, Renaissance, Early modern, Modern, and Future. Its main user-accessible client is {{What era is}}, but the main use is for {{Author}} (through Module:Author) and its automatically added categories (the subcategories of Category:Authors by era).

The named eras represent years as follows:

Era	Years
Ancient	Before 600
Medieval	601–1420
Renaissance	1421–1630
Early modern	1631–1900
Modern	1901–2024
Future	2025–

Use

From template code the function is called with {{#invoke:Era|main}} and the year parameter is extracted from the calling frame (the arguments given to the template). See {{What era is}} for an example. From a wikipage the year can be provided directly in the invocation: {{#invoke:Era|main|1623}} → Renaissance.

From a Lua module there is a simplified (and nominally faster) calling convention that avoids the need for having a frame object or checking the parent frame. After loading the module (local e = require Module:Era) you can call its .era() function with a year as the only parameter: local era = e.era(1623).

However called the return value is always a plain string with no markup or styling.

---

--[[
  Get the name of an era, based on Wikisource's definition.
  This implements the logic of Template:What era is
--]]
require('strict')

local getArgs = require('Module:Arguments').getArgs
local p = {}

function p.main(frame)
	local args = getArgs(frame, {
		wrappers = {
			'Template:What era is',
		}
	})
	return p.era(args[1])
end

function p.era(year)
	-- Nil years need to trigger bailout before we do anything else.
	if year == nil then
		return 'Unknown era'
	end

	--[[
		The template (What era is) treated every year that failed to parse as
		"Ancient", and years given as "BCE" fell into this category. With the
		module logic this no loonger works, so we need to treat BCE years as
		negative instead, so the numeric logic can deal wiith them.
	--]]
	if mw.ustring.match(year, ' BCE$') ~= nil then
		year = mw.ustring.gsub(year, ' BCE$', '') -- Strip the "BCE"
		year = '-' .. year -- And prepend a minus (we tonumber() it later)
	end

	-- Unknown value.
	if tonumber(year) == nil or mw.ustring.lower(year) == 'unknown' or year == '?' then
		return 'Unknown era'
	end

	-- Handle numeric years.
	year = tonumber(year)
	local today = tonumber(os.date('%Y'))
	if year <= 600 then
		return 'Ancient'
	elseif year <= 1420 then
		return 'Medieval'
	elseif year <= 1630 then
		return 'Renaissance'
	elseif year <= 1900 then
		return 'Early modern'
	elseif year <= today then
		return 'Modern'
	else
		return 'Future'
	end
end


return p