Added flatbuffers support to the PluginBase::Error

This changes BREAKS osrm.

src/engine/plugins/table.cpp

@@ -33,7 +33,6 @@ Status TablePlugin::HandleRequest(const RoutingAlgorithmsInterface &algorithms,
                                   const api::TableParameters &params,
                                   osrm::engine::api::ResultT &result) const
 {
-    auto& json_result = result.get<util::json::Object>();
     if (!algorithms.HasManyToManySearch())
     {
         return Error("NotImplemented",
@@ -155,6 +154,7 @@ Status TablePlugin::HandleRequest(const RoutingAlgorithmsInterface &algorithms,
     }
 
     api::TableAPI table_api{facade, params};
+    auto& json_result = result.get<util::json::Object>();
     table_api.MakeResponse(result_tables_pair, snapped_phantoms, estimated_pairs, json_result);
 
     return Status::Ok;

src/server/service/table_service.cpp

@@ -97,6 +97,12 @@ TableService::RunQuery(std::size_t prefix_length, std::string &query, osrm::engi
     }
     BOOST_ASSERT(parameters->IsValid());
 
+    if (parameters->format)
+    {
+        if (parameters->format == engine::api::BaseParameters::OutputFormatType::FLATBUFFERS) {
+            result = flatbuffers::FlatBufferBuilder();
+        }
+    }
     return BaseService::routing_machine.Table(*parameters, result);
 }
 }