Change an argument for converting the parameters to be std::optional

CMakeLists.txt

@@ -16,6 +16,7 @@ k4edm4hep2lcioconv_set_linker_flags()
 find_package(LCIO 2.22 REQUIRED)
 find_package(podio 1.0 REQUIRED)
 find_package(EDM4HEP 0.99 REQUIRED)
+find_package(k4FWCore REQUIRED)
 find_package(ROOT REQUIRED COMPONENTS MathCore)
 
 add_subdirectory(k4EDM4hep2LcioConv)

k4EDM4hep2LcioConv/CMakeLists.txt

@@ -13,6 +13,7 @@ target_link_libraries(k4EDM4hep2LcioConv PUBLIC
   EDM4HEP::edm4hep
   EDM4HEP::utils
   ROOT::MathCore
+  k4FWCore::k4FWCore
 )
 
 set(public_headers

k4EDM4hep2LcioConv/include/k4EDM4hep2LcioConv/k4Lcio2EDM4hepConv.ipp

@@ -2,44 +2,59 @@
 
 #include <UTIL/PIDHandler.h>
 
+#include "podio/Frame.h"
+
 #include <edm4hep/ParticleIDCollection.h>
 #include <edm4hep/RecDqdxCollection.h>
 
+#include "k4FWCore/MetadataUtils.h"
+
 namespace LCIO2EDM4hepConv {
 template <typename LCIOType>
-void convertObjectParameters(LCIOType* lcioobj, podio::Frame& event) {
+void convertObjectParameters(LCIOType* lcioobj, std::optional<std::reference_wrapper<podio::Frame>>& event) {
   const auto& params = lcioobj->getParameters();
+
+  // When using the PodioDataSvc there is always access to the event frame
+  // but when using IOSvc there is not a frame
+  auto putParamFun = [&](const std::string& key, const auto& value) {
+    if (event) {
+      event->get().putParameter(key, value);
+    } else {
+      k4FWCore::putParameter(key, value);
+    }
+  };
+
   // handle srting params
   EVENT::StringVec keys;
   const auto stringKeys = params.getStringKeys(keys);
   for (auto i = 0u; i < stringKeys.size(); i++) {
     EVENT::StringVec sValues;
     const auto stringVals = params.getStringVals(stringKeys[i], sValues);
-    event.putParameter(stringKeys[i], stringVals);
+    putParamFun(stringKeys[i], stringVals);
   }
   // handle float params
   EVENT::StringVec fkeys;
   const auto floatKeys = params.getFloatKeys(fkeys);
   for (auto i = 0u; i < floatKeys.size(); i++) {
     EVENT::FloatVec fValues;
     const auto floatVals = params.getFloatVals(floatKeys[i], fValues);
-    event.putParameter(floatKeys[i], floatVals);
+    putParamFun(floatKeys[i], floatVals);
   }
   // handle int params
   EVENT::StringVec ikeys;
   const auto intKeys = params.getIntKeys(ikeys);
   for (auto i = 0u; i < intKeys.size(); i++) {
     EVENT::IntVec iValues;
     const auto intVals = params.getIntVals(intKeys[i], iValues);
-    event.putParameter(intKeys[i], intVals);
+    putParamFun(intKeys[i], intVals);
   }
   // handle double params
   EVENT::StringVec dkeys;
   const auto dKeys = params.getDoubleKeys(dkeys);
   for (auto i = 0u; i < dKeys.size(); i++) {
     EVENT::DoubleVec dValues;
     const auto dVals = params.getDoubleVals(dKeys[i], dValues);
-    event.putParameter(dKeys[i], dVals);
+    putParamFun(dKeys[i], dVals);
   }
 }
 

k4EDM4hep2LcioConv/src/k4Lcio2EDM4hepConv.cpp

@@ -126,8 +126,9 @@ podio::Frame convertEvent(EVENT::LCEvent* evt, const std::vector<std::pair<std::
 
   // Now everything is done and we simply populate a Frame
   podio::Frame event;
+  std::optional<std::reference_wrapper<podio::Frame>> eventOpt = event;
   // convert put the event parameters into the frame
-  convertObjectParameters<EVENT::LCEvent>(evt, event);
+  convertObjectParameters<EVENT::LCEvent>(evt, eventOpt);
 
   // only create CaloHitContributions if necessary (i.e. if we have converted
   // SimCalorimeterHits)
@@ -154,7 +155,8 @@ podio::Frame convertRunHeader(EVENT::LCRunHeader* rheader) {
   runHeaderFrame.putParameter("activeSubdetectors", *subdetectors);
 
   // convert everything set as a parameter
-  convertObjectParameters<EVENT::LCRunHeader>(rheader, runHeaderFrame);
+  std::optional<std::reference_wrapper<podio::Frame>> runHeaderFrameOpt = runHeaderFrame;
+  convertObjectParameters<EVENT::LCRunHeader>(rheader, runHeaderFrameOpt);
 
   return runHeaderFrame;
 }