Module:If preview

This module implements {{If preview}} and {{Preview warning}}. It helps templates/modules determine if they are being previewed.

Prefer implementing the template versions in other templates.

In a module to use the main(), you need to pass a frame table with an args table.

For the preview warning, use _warning().

Attribution and re-use

This module (along with its documentation page) has been adapted from Wikipedia released under the Creative Commons Attribution-ShareAlike License 4.0.

---

local p = {}

local cfg = mw.loadData('Module:If preview/configuration')

--[[
main

This function returns either the first argument or second argument passed to
this module, depending on whether the page is being previewed.

]]
function p.main(frame)
	if cfg.preview then
		return frame.args[1] or ''
	else
		return frame.args[2] or ''
	end
end

--[[
pmain

This function returns either the first argument or second argument passed to
this module's parent (i.e. template using this module), depending on whether it
is being previewed.

]]
function p.pmain(frame)
	return p.main(frame:getParent())
end

function p._warning(args)
	
	local warning = args[1] and args[1]:match('^%s*(.-)%s*$') or ''
	if warning == '' then
		return cfg.missing_warning
	end
	
	if not cfg.preview then return '' end
	
	return warning
end

--[[
warning

This function returns a "preview warning", which is the first argument marked
up with HTML and some supporting text, depending on whether the page is being previewed.

disabled since we'll implement the template version in general

]]
--function p.warning(frame)
--	return p._warning(frame.args)
--end

--[[
warning, but for pass-through templates like {{preview warning}}
]]
function p.pwarning(frame)
	return p._warning(frame:getParent().args)
end

return p