Module:Utils

Utility functions to help creating modules

def(value, default)

Returns value if it is not nil or "", and defaultotherwise

_a(arg)

Extracts the argument from the common ways mediawiki passes arguments to modules:

• if arg is not a table, it is returned as is (Called from Lua like a function)
• if arg is a table and that table has a args field, arg.args[1] is returned (Called from MediaWiki’s {{#invoke:}} parser function)
• if arg is a table but doesn’t contain an args field, args[1] is returned (Called with a table as an argument list)

date(y, m, d, short = false)

Formats a date.

If short is set to true, uses shortened months name instead of full length month names.

find(tab, field, val)

Locate an entry in a list of table (useful for search through json data)

Parameters

tab: table: the list to search through

field: any: the field in the objects to search by

value: any: the value to match against

Returns

nil, nil if the value wasn't found

index, value: the index at which the match is, and its value

---

local _m = {}

--- Return a if not `nil` or the empty string, or b otherwise
_m.def = function(a, b)
	return (a ~= nil and a ~= "") and a or b
end
--- Extracts the argument from all the reasonable ways an argument may have been passed
_m._a = function (x)
	if type(x) ~= "table" then
		return x
	end
	-- Did we get a frame
	if type(x.args) == "table" then return x.args[1] end
	-- Also support passing the argument in a table
	return x[1]
end

_m.date = function(y, m, d, short)
	local months
	if short then months = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}
	else months = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"}
	end
	return tostring(d) .. " " .. tostring(months[m]) .. " " .. tostring(y)
end

_m.find = function(tab, field, val)
	for i, v in ipairs(tab) do
		if v[field] == val then return i, v end
	end
	return nil
end
return _m