Map Merge

gistfile1.txt

defmodule PMTest do
	
	def apply_defaults(json_obj) do
		Map.merge(json_obj, defaults, fn _,v1,v2 ->
			case v1 do
				nil -> v2
				_ -> v1
			end
		end)
	end

	def defaults do
		%{def1: "default_one", def2: "default_two", def3: "default_three"}
	end
end