Module:If preview

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This Lua module is used on many pages and changes may be widely noticed. Test changes in the module's /sandbox or /testcases subpages, or in your own module sandbox. Consider discussing changes on the talk page before implementing them.

Lua error in Module:Lua_banner at line 113: attempt to index field 'edit' (a nil value).

This module uses TemplateStyles:

Module:If preview/styles.css (sandbox)

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().

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


local function warning_text(warning)
	return mw.ustring.format(
		cfg.warning_infrastructure,
		cfg.templatestyles,
		warning
	)
end

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