Flag for testing available model before allowing solution and explicit checking JSON keys for metric updates

Change-Id: Ib2bc4b5273159077e3eaa7786cc2c846110791d0

AMPLSolver.cpp

@@ -195,6 +195,11 @@ void AMPLSolver::DefineProblem(const Solver::OptimisationProblem & TheProblem,
       SetAMPLParameter( ConstantName, 
                         ConstantRecord.at( InitialConstantValue ) );
     }
+
+  // Finally, the problem has been defined and the flag is set to allow 
+  // the search for solutions for this problem.
+
+  ProblemUndefined = false;
 }
 
 // -----------------------------------------------------------------------------
@@ -225,6 +230,10 @@ void AMPLSolver::DataFileUpdate( const DataFileMessage & TheDataFile,
 void AMPLSolver::SolveProblem( 
   const ApplicationExecutionContext & TheContext, const Address TheRequester )
 {
+  // There is nothing to do if the application model is missing.
+
+  if( ProblemUndefined ) return;
+
   // Setting the metric values one by one. In the setting of NebulOuS a metric
   // is either a numerical value or a string. Vectors are currently not
   // supported as values.
@@ -356,6 +365,7 @@ AMPLSolver::AMPLSolver( const std::string & TheActorName,
   Solver( Actor::GetAddress().AsString() ),
   ProblemFileDirectory( ProblemPath ),
   ProblemDefinition( InstallationDirectory ),
+  ProblemUndefined( true ),
   DefaultObjectiveFunction(), VariablesToConstants()
 {
   RegisterHandler( this, &AMPLSolver::DataFileUpdate );

AMPLSolver.hpp

@@ -153,6 +153,14 @@ protected:
          VariableName         = "Variable",
          InitialConstantValue = "Value";
 
+  // Finally, no solution will be produced unless the problem has been 
+  // defined. A flag is therefore set by the message handler indicating 
+  // that the problem has been defined.
+
+private:
+
+  bool ProblemUndefined;
+
   // The AMPL problem file can contain many objective functions, but can be 
   // solved only for one objective function at the time. The name of the 
   // default objective function is therefore stored together with the model 
@@ -160,8 +168,6 @@ protected:
   // label is not provided with the optimisation problem message, an 
   // invalid argument exception will be thrown.
 
-private:
-
   std::string DefaultObjectiveFunction;
 
   // To set the constant values to the right variable values, the mapping 

MetricUpdater.cpp

@@ -142,10 +142,10 @@ void MetricUpdater::UpdateMetricValue(
 
   if( MetricValues.contains( TheTopic ) )
   {
-    MetricValues.at( TheTopic ) = TheMetricValue[ NebulOuS::ValueLabel ];
+    MetricValues.at( TheTopic ) = TheMetricValue.at( NebulOuS::ValueLabel );
     
     ValidityTime = std::max( ValidityTime, 
-      TheMetricValue[ NebulOuS::TimePoint ].get< Solver::TimePointType >() );
+      TheMetricValue.at( NebulOuS::TimePoint ).get< Solver::TimePointType >() );
   }
 }