changing LogWarning printout such that it is not raised for each tau …

…but only at first occurence per instance

PhysicsTools/PatAlgos/plugins/PATTauProducer.cc

@@ -32,6 +32,7 @@ PATTauProducer::PATTauProducer(const edm::ParameterSet & iConfig):
   isolator_(iConfig.exists("userIsolation") ? iConfig.getParameter<edm::ParameterSet>("userIsolation") : edm::ParameterSet(), consumesCollector(), false) ,
   useUserData_(iConfig.exists("userData"))
 {
+  firstOccurence_=true;
   // initialize the configurables
   baseTauToken_ = consumes<edm::View<reco::BaseTau> >(iConfig.getParameter<edm::InputTag>( "tauSource" ));
   tauTransverseImpactParameterSrc_ = iConfig.getParameter<edm::InputTag>( "tauTransverseImpactParameterSource" );
@@ -306,6 +307,7 @@ void PATTauProducer::produce(edm::Event & iEvent, const edm::EventSetup & iSetup
 
     // prepare ID extraction
     if ( addTauID_ ) {
+      std::string missingDiscriminators;
       std::vector<pat::Tau::IdPair> ids(tauIDSrcs_.size());
       for ( size_t i = 0; i < tauIDSrcs_.size(); ++i ) {
 	if ( typeid(*tausRef) == typeid(reco::PFTau) ) {
@@ -317,8 +319,10 @@ void PATTauProducer::produce(edm::Event & iEvent, const edm::EventSetup & iSetup
 	  iEvent.getByToken(pfTauIDTokens_[i], pfTauIdDiscr);
 
 	  if(skipMissingTauID_ && !pfTauIdDiscr.isValid()){
-	    edm::LogWarning("DataSource") << "Tau discriminator '" << tauIDSrcs_[i].first
-					  << "' has not been found in the event. It will not be embedded into the pat::Tau object.";
+	    if(!missingDiscriminators.empty()){
+	      missingDiscriminators+=", ";
+	    }
+	    missingDiscriminators+=tauIDSrcs_[i].first;
 	    continue;
 	  }
 	  ids[i].first = tauIDSrcs_[i].first;
@@ -332,8 +336,10 @@ void PATTauProducer::produce(edm::Event & iEvent, const edm::EventSetup & iSetup
 	  iEvent.getByToken(caloTauIDTokens_[i], caloTauIdDiscr);
 
 	  if(skipMissingTauID_ && !caloTauIdDiscr.isValid()){
-	    edm::LogWarning("DataSource") << "Tau discriminator '" << tauIDSrcs_[i].first
-					  << "' has not been found in the event. It will not be embedded into the pat::Tau object.";
+	    if(!missingDiscriminators.empty()){
+	      missingDiscriminators+=", ";
+	    }
+	    missingDiscriminators+=tauIDSrcs_[i].first;
 	    continue;
 	  }
 	  ids[i].first = tauIDSrcs_[i].first;
@@ -343,7 +349,13 @@ void PATTauProducer::produce(edm::Event & iEvent, const edm::EventSetup & iSetup
 	    "PATTauProducer: unsupported datatype '" << typeid(*tausRef).name() << "' for tauSource\n";
 	}
       }
-
+      if(!missingDiscriminators.empty() && firstOccurence_){
+	edm::LogWarning("DataSource") << "The following tau discriminators have not been found in the event:\n" 
+				      << missingDiscriminators <<"\n"
+				      << "They will not be embedded into the pat::Tau object.\n"
+				      << "Note: this message will be printed only at first occurence.";
+	firstOccurence_=false;
+      }
       aTau.setTauIDs(ids);
     }
 

PhysicsTools/PatAlgos/plugins/PATTauProducer.h

@@ -55,7 +55,8 @@ namespace pat {
       static void fillDescriptions(edm::ConfigurationDescriptions & descriptions);
 
     private:
-
+      bool firstOccurence_; // used to print LogWarnings only at first occurnece in the event loop
+
       // configurables
       edm::EDGetTokenT<edm::View<reco::BaseTau> > baseTauToken_;
       edm::EDGetTokenT<PFTauTIPAssociationByRef> tauTransverseImpactParameterToken_;