getRootNode() ->children() ->scalarNode("issuer") ->isRequired() ->cannotBeEmpty() ->end() ->scalarNode("realm") ->isRequired() ->cannotBeEmpty() ->end() ->scalarNode("client_id") ->isRequired() ->cannotBeEmpty() ->end() ->scalarNode("client_secret") ->isRequired() ->cannotBeEmpty() ->end(); return $treeBuilder; } }