Registered definitions

Anything added using certain [Registration functions] gets added to one or more of the global [Registered definition tables].

Note that in some cases you will stumble upon things that are not contained in these tables (e.g. when a mod has been removed). Always check for existence before trying to access the fields.

Example:

All nodes register with minetest.register_node get added to the table minetest.registered_nodes.

If you want to check the drawtype of a node, you could do:

local function get_nodedef_field(nodename, fieldname)
    if not minetest.registered_nodes[nodename] then
        return nil
    end
    return minetest.registered_nodes[nodename][fieldname]
end
local drawtype = get_nodedef_field(nodename, "drawtype")