Fix #4125, Fix #4135 - GbXML ForwardTranslator: clear map&set, and add a modelToGbXMLString method

src/gbxml/ForwardTranslator.cpp

@@ -122,6 +122,31 @@ namespace gbxml {
     return false;
   }
 
+  std::string ForwardTranslator::modelToGbXMLString(const openstudio::model::Model& model, ProgressBar* progressBar)
+  {
+    std::string gbXML_str;
+
+    m_progressBar = progressBar;
+
+    m_logSink.setThreadId(std::this_thread::get_id());
+
+    m_logSink.resetStringStream();
+
+    pugi::xml_document doc;
+    //doc.createProcessingInstruction("xml", "version=\"1.0\" encoding=\"utf-8\"");
+    bool result = this->translateModel(model, doc);
+
+    if (result) {
+      // doc.save allows any ostream, so use a stringstream
+      std::stringstream ss;
+      doc.save(ss, "  ");
+      gbXML_str = ss.str();
+    }
+
+    return gbXML_str;
+  }
+
+
   std::vector<LogMessage> ForwardTranslator::warnings() const
   {
     std::vector<LogMessage> result;
@@ -174,6 +199,11 @@ namespace gbxml {
 
   bool ForwardTranslator::translateModel(const openstudio::model::Model& model, pugi::xml_document& document)
   {
+
+    // Clear the map & set
+    m_translatedObjects.clear();
+    m_materials.clear();
+
     auto gbXMLElement = document.append_child("gbXML");
     gbXMLElement.append_attribute("xmlns") = "http://www.gbxml.org/schema";
     gbXMLElement.append_attribute("xmlns:xhtml") = "http://www.w3.org/1999/xhtml";

src/gbxml/ForwardTranslator.hpp

@@ -78,8 +78,12 @@ namespace gbxml {
 
     virtual ~ForwardTranslator();
 
+    // Save the GbXML to a file
     bool modelToGbXML(const openstudio::model::Model& model, const openstudio::path& path, ProgressBar* progressBar = nullptr);
 
+    // Return a string representation of the GbXML document
+    std::string modelToGbXMLString(const openstudio::model::Model& model, ProgressBar* progressBar = nullptr);
+
       /** Get warning messages generated by the last translation. */
     std::vector<LogMessage> warnings() const;
 

src/gbxml/Test/ForwardTranslator_GTest.cpp

@@ -329,3 +329,19 @@ TEST_F(gbXMLFixture, ForwardTranslator_surfaceType_4001)
   std::string expectedSurfaceType("SlabOnGrade");
   EXPECT_EQ(expectedSurfaceType, surfaceType);
 }
+
+TEST_F(gbXMLFixture, ForwardTranslator_exampleModel_State)
+{
+  // Test for #4135: translating a model twice should produce the same result
+  Model model = exampleModel();
+
+  ForwardTranslator forwardTranslator;
+  std::string gbXML_str1 = forwardTranslator.modelToGbXMLString(model);
+  EXPECT_FALSE(gbXML_str1.empty());
+
+  std::string gbXML_str2 = forwardTranslator.modelToGbXMLString(model);
+  EXPECT_FALSE(gbXML_str2.empty());
+
+  EXPECT_EQ(gbXML_str1.length(), gbXML_str2.length());
+  EXPECT_GT(gbXML_str1.length(), 50000);
+}