From 09c5759a9fe15a1ff6517113f8a56d2b4080835b Mon Sep 17 00:00:00 2001
From: Thomas Krijnen <t.krijnen@gmail.com>
Date: Fri, 7 Sep 2018 14:25:46 +0200
Subject: [PATCH] Emit error messages on missing units

---
 src/ifcgeom/IfcGeomFunctions.cpp | 12 ++++++++++++
 src/ifcgeom/IfcGeomIterator.h    |  2 ++
 2 files changed, 14 insertions(+)

diff --git a/src/ifcgeom/IfcGeomFunctions.cpp b/src/ifcgeom/IfcGeomFunctions.cpp
index 7ed8ddc228..feb851b803 100644
--- a/src/ifcgeom/IfcGeomFunctions.cpp
+++ b/src/ifcgeom/IfcGeomFunctions.cpp
@@ -1580,6 +1580,8 @@ std::pair<std::string, double> IfcGeom::Kernel::initializeUnits(IfcSchema::IfcUn
 	std::string unit_name = "METER";
 	double unit_magnitude = 1.;
 
+	bool length_unit_encountered = false, angle_unit_encountered = false;
+
 	try {
 		IfcEntityList::ptr units = unit_assignment->Units();
 		if (!units || !units->size()) {
@@ -1609,8 +1611,10 @@ std::pair<std::string, double> IfcGeom::Kernel::initializeUnits(IfcSchema::IfcUn
 								unit_name = current_unit_name;
 								unit_magnitude = current_unit_magnitude;
 								setValue(IfcGeom::Kernel::GV_LENGTH_UNIT, current_unit_magnitude);
+								length_unit_encountered = true;
 							} else {
 								setValue(IfcGeom::Kernel::GV_PLANEANGLE_UNIT, current_unit_magnitude);
+								angle_unit_encountered = true;
 							}
 						}
 					}
@@ -1623,6 +1627,14 @@ std::pair<std::string, double> IfcGeom::Kernel::initializeUnits(IfcSchema::IfcUn
 		Logger::Message(Logger::LOG_ERROR, ss.str());
 	}
 
+	if (!length_unit_encountered) {
+		Logger::Error("No length unit encountered");
+	}
+
+	if (!angle_unit_encountered) {
+		Logger::Error("No plane angle unit encountered");
+	}
+
 	return std::pair<std::string, double>(unit_name, unit_magnitude);
 }
 
diff --git a/src/ifcgeom/IfcGeomIterator.h b/src/ifcgeom/IfcGeomIterator.h
index e6898df684..499f042c48 100644
--- a/src/ifcgeom/IfcGeomIterator.h
+++ b/src/ifcgeom/IfcGeomIterator.h
@@ -145,6 +145,8 @@ namespace IfcGeom {
 				std::pair<std::string, double> length_unit = kernel.initializeUnits(project->UnitsInContext());
 				unit_name = length_unit.first;
 				unit_magnitude = length_unit.second;
+			} else {
+				Logger::Error("A single IfcProject is expected (encountered " + boost::lexical_cast<std::string>(projects->size()) + "); unable to read unit information.");
 			}
 		}