Use the filename in FileBackExperimentInfo

It turns out that the NeXus object is not as persistent throughout
the system as was first suspected.
Refs #11220

Code/Mantid/Framework/API/inc/MantidAPI/FileBackedExperimentInfo.h

@@ -37,7 +37,7 @@ namespace API {
 class MANTID_API_DLL FileBackedExperimentInfo : public ExperimentInfo {
 public:
   /// Constructor
-  FileBackedExperimentInfo(::NeXus::File *file, const std::string &path);
+  FileBackedExperimentInfo(const std::string & filename, const std::string &path);
 
   ExperimentInfo *cloneExperimentInfo() const;
 
@@ -99,8 +99,8 @@ class MANTID_API_DLL FileBackedExperimentInfo : public ExperimentInfo {
   void populateFromFile() const;
 
   mutable bool m_loaded;
-  ::NeXus::File *m_file;
-  std::string m_path;
+  std::string m_filename;
+  std::string m_nxpath;
 };
 
 } // namespace API

Code/Mantid/Framework/API/src/FileBackedExperimentInfo.cpp

@@ -2,10 +2,13 @@
 // Includes
 //----------------------------------------------------------------------------------------------
 #include "MantidAPI/FileBackedExperimentInfo.h"
-#include <nexus/NeXusException.hpp>
 
 #include <sstream>
 
+#include <nexus/NeXusException.hpp>
+#include <nexus/NeXusFile.hpp>
+
+
 namespace Mantid {
 namespace API {
 
@@ -17,12 +20,12 @@ Kernel::Logger g_log("FileBackedExperimentInfo");
 
 /**
   * Create an object based on a NeXus file and path
-  * @param file A pointer to an open NeXus file object
-  * @param path Path to the location of the data
+  * @param filename The full path to the file
+  * @param nxpath Path to the location of the experiment information
   */
-FileBackedExperimentInfo::FileBackedExperimentInfo(::NeXus::File *file,
-                                                   const std::string &path)
-    : ExperimentInfo(), m_loaded(false), m_file(file), m_path(path) {}
+FileBackedExperimentInfo::FileBackedExperimentInfo(const std::string &filename,
+                                                   const std::string &nxpath)
+    : ExperimentInfo(), m_loaded(false), m_filename(filename), m_nxpath(nxpath) {}
 
 /**
  * @return A clone of the object
@@ -288,15 +291,16 @@ void FileBackedExperimentInfo::populateIfNotLoaded() const {
  */
 void FileBackedExperimentInfo::populateFromFile() const {
   try {
-    m_file->openPath(m_path);
+    ::NeXus::File nxFile(m_filename);
+    nxFile.openPath(m_nxpath);
     // The loadExperimentInfo calls things such as mutableSample()
     // and if m_loaded is not true then this function is
     // will be called recursively.
     m_loaded = true;
 
     std::string parameterStr;
     const_cast<FileBackedExperimentInfo *>(this)
-        ->loadExperimentInfoNexus(m_file, parameterStr);
+        ->loadExperimentInfoNexus(&nxFile, parameterStr);
     const_cast<FileBackedExperimentInfo *>(this)
         ->readParameterMap(parameterStr);
   } catch (::NeXus::Exception &exc) {

Code/Mantid/Framework/API/test/FileBackedExperimentInfoTest.h

@@ -33,10 +33,10 @@ class FileBackedExperimentInfoTest : public CxxTest::TestSuite {
     }
 
     m_inMemoryExptInfo = boost::make_shared<ExperimentInfo>();
-    m_nexusFile = boost::make_shared< ::NeXus::File >(m_filename, NXACC_READ);
-    m_nexusFile->openGroup("mantid_workspace_1", "NXentry");
+    ::NeXus::File nxFile(m_filename, NXACC_READ);
+    nxFile.openGroup("mantid_workspace_1", "NXentry");
     std::string paramString;
-    m_inMemoryExptInfo->loadExperimentInfoNexus(m_nexusFile.get(), paramString);
+    m_inMemoryExptInfo->loadExperimentInfoNexus(&nxFile, paramString);
     m_inMemoryExptInfo->readParameterMap(paramString);
   }
 
@@ -215,27 +215,20 @@ class FileBackedExperimentInfoTest : public CxxTest::TestSuite {
   // Failure tests
   //------------------------------------------------------------------------------------------------
   void test_runtime_error_generated_when_unable_to_load_from_file() {
-    // Load the file we want to use
-    ::NeXus::File nexusFile(m_filename, NXACC_READ);
-
     // Create the file backed experiment info, shouldn't be loaded yet
-    FileBackedExperimentInfo fileBacked(&nexusFile, "/not/right/path");
+    FileBackedExperimentInfo fileBacked(m_filename, "/not/right/path");
 
     TS_ASSERT_THROWS(fileBacked.toString(), std::runtime_error);
   }
 
 private:
   Mantid::API::ExperimentInfo_sptr createTestObject() {
-    // Load the file we want to use
-    ::NeXus::File nexusFile(m_filename, NXACC_READ);
     // Create the file backed experiment info, shouldn't be loaded yet.
-    // Manipulate it through
-    // the interface
-    return boost::make_shared<FileBackedExperimentInfo>(m_nexusFile.get(),
+    // Manipulate it through the interface
+    return boost::make_shared<FileBackedExperimentInfo>(m_filename,
                                                         "/mantid_workspace_1");
   }
 
-  boost::shared_ptr< ::NeXus::File > m_nexusFile;
   Mantid::API::ExperimentInfo_sptr m_inMemoryExptInfo;
   std::string m_filename;
 };