save_metadata = function(node)
	--print('saving metadata for', node.id)
	local mfile = metadata_file(node.id)
	local mpath
	if node.metadata.parent then
		mpath = full_path('comments/'..mfile)
	else
		mpath = full_path(mfile)
	end
	print('saving metadata for', node.id, 'to', mpath)
	local status, err = App.write_file(mpath, json.encode(node.metadata))
	if err then
		error(err)
	end
end