FileLoaderRegistry now subscribes algorithms to factory

and also defines two types of loader, NonHDF and HDF.
Refs #7263

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

@@ -2,9 +2,11 @@
 #define MANTID_API_FILELOADERREGISTRY_H_
 
 #include "MantidAPI/DllConfig.h"
+#include "MantidAPI/AlgorithmFactory.h"
 
 #include <set>
 #include <string>
+#include <vector>
 
 namespace Mantid
 {
@@ -45,20 +47,42 @@ namespace Mantid
      */
     class MANTID_API_DLL FileLoaderRegistry
     {
+    public:
+
+      /// Defines types of possible file
+      enum LoaderFormat { NonHDF, HDF };
+
     public:
       /// Default constructor
       FileLoaderRegistry();
 
       /// @returns the number of entries in the registry
-      inline size_t size() const { return m_names.size(); }
-      /// Adds an entry
-      void subscribe(const std::string & name);
-      /// Pick the best loader for the given filename
-      std::string findLoader(const std::string & filename) const;
+      inline size_t size() const { return m_totalSize; }
+
+      /**
+       * Registers a loader whose format is one of the known formats given in LoaderFormat. It
+       * also passes this registration on to the AlgorithmFactory so that it can be created.
+       * The template type should be the class being registered. The name is taken from the string
+       * returned by the name() method on the object.
+       * @param format The type of loader being subscribed, see LoaderFormat
+       * @throws std::invalid_argument if an entry with this name already exists
+       */
+      template<typename Type>
+      void subscribe(LoaderFormat format)
+      {
+        const std::string name = AlgorithmFactory::Instance().subscribe<Type>();
+        // If the factory didn't throw then the name is valid
+        m_names[format].insert(name);
+        m_totalSize += 1;
+        m_log.debug() << "Registered '" << name << "' as file loader\n";
+      }
 
     private:
-      /// The registered names
-      std::set<std::string> m_names;
+      /// The list of names. The index pointed to by LoaderFormat defines a set for that format
+      std::vector<std::set<std::string> > m_names;
+      /// Total number of names registered
+      size_t m_totalSize;
+
       /// Reference to a logger
       Kernel::Logger & m_log;
     };

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

@@ -6,15 +6,33 @@
 
 /**
  * DECLARE_FILELOADER_ALGORITHM should be used in place of the standard
- * DECLARE_ALGORITHM macro that both registers the algorithm as usual and subscribes it to the
+ * DECLARE_ALGORITHM macro when writing a file loading algorithm that
+ * loads data from a non-hierarchical format.
+ * It both registers the algorithm as usual and subscribes it to the
  * registry held in the FrameworkManager
  */
 #define DECLARE_FILELOADER_ALGORITHM(classname) \
-  DECLARE_ALGORITHM(classname) \
   namespace \
   {\
     Mantid::Kernel::RegistrationHelper \
-      reg_loader_##classname((Mantid::API::FrameworkManager::Instance().fileLoaderRegistry().subscribe(#classname), 0));\
+      reg_loader_##classname((Mantid::API::\
+        FrameworkManager::Instance().fileLoaderRegistry().subscribe<classname>(Mantid::API::FileLoaderRegistry::NonHDF), 0));\
   }
 
+/**
+ * DECLARE_HDF_FILELOADER_ALGORITHM should be used in place of the standard
+ * DECLARE_ALGORITHM macro when writing a file loading algorithm that
+ * loads data from a hierarchical format, e.g. NeXus, HDF.
+ * It both registers the algorithm as usual and subscribes it to the
+ * registry held in the FrameworkManager
+ */
+#define DECLARE_HDF_FILELOADER_ALGORITHM(classname) \
+  namespace \
+  {\
+    Mantid::Kernel::RegistrationHelper \
+      reg_hdf_loader_##classname((Mantid::API::\
+        FrameworkManager::Instance().fileLoaderRegistry().subscribe<classname>(Mantid::API::FileLoaderRegistry::HDF), 0)); \
+  }
+
+
 #endif /* MANTID_API_REGISTERFILELOADER_H_ */

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

@@ -14,41 +14,12 @@ namespace Mantid
     /**
      * Creates an empty registry
      */
-    FileLoaderRegistry::FileLoaderRegistry() : m_log(Kernel::Logger::get("FileLoaderRegistry"))
+    FileLoaderRegistry::FileLoaderRegistry() :
+        m_names(2, std::set<std::string>()), m_totalSize(0),
+        m_log(Kernel::Logger::get("FileLoaderRegistry"))
     {
     }
 
-    /**
-     * @param name The string name of the entry
-     * @throws std::invalid_argument if an entry with this name already exists
-     */
-    void FileLoaderRegistry::subscribe(const std::string & name)
-    {
-      auto insertionResult = m_names.insert(name);
-      if(!insertionResult.second)
-      {
-        throw std::invalid_argument("FileLoaderRegistry::subscribe - Cannot subscribe '"
-            + name + "'. An entry with that name already exists");
-      }
-      m_log.debug() << "Registered '" << name << "' as file loader\n";
-    }
-
-    /**
-     * Attempts to pick the best suited loader for the given file name from those in the registry
-     * @param filename A string that should point to an existing file
-     * @throws std::invalid_argument if the filename does not point to an existing file or an empty string is given
-     * @throws Exception::NotFoundError if a loader could not be found
-     */
-    std::string FileLoaderRegistry::findLoader(const std::string & filename) const
-    {
-      if(filename.empty() || !Poco::File(filename).exists())
-      {
-        throw std::invalid_argument("FileLoaderRegistry::chooserLoader - Cannot open file '" + filename + "'");
-      }
-      m_log.debug() << "Attempting to find loader for '" << filename << "'\n";
-      throw std::runtime_error("not implemented yet");
-    }
-
     //----------------------------------------------------------------------------------------------
     // Private members
     //----------------------------------------------------------------------------------------------

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

@@ -2,6 +2,7 @@
 #define MANTID_API_FILELOADERREGISTRYTEST_H_
 
 #include <cxxtest/TestSuite.h>
+#include "MantidAPI/Algorithm.h"
 #include "MantidAPI/FileLoaderRegistry.h"
 
 using Mantid::API::FileLoaderRegistry;
@@ -25,27 +26,35 @@ class FileLoaderRegistryTest : public CxxTest::TestSuite
   {
     FileLoaderRegistry registry;
 
-    TS_ASSERT_THROWS_NOTHING(registry.subscribe("LoadEventNexus"));
+    TS_ASSERT_THROWS_NOTHING(registry.subscribe<StubAlgorithm>(FileLoaderRegistry::NonHDF));
     TS_ASSERT_EQUALS(1, registry.size());
+
+    // We can't mock the factory as it's a singleton so make sure we clean up
+    Mantid::API::AlgorithmFactory::Instance().unsubscribe("StubAlgorithm", 1);
   }
 
   // ======================== Failure cases ===================================
   void test_Adding_Entry_That_Already_Exists_Throws_Error_And_Keeps_The_Size_The_Same()
   {
     FileLoaderRegistry registry;
-    registry.subscribe("LoadEventNexus");
+    registry.subscribe<StubAlgorithm>(FileLoaderRegistry::NonHDF);
 
-    TS_ASSERT_THROWS(registry.subscribe("LoadEventNexus"), std::invalid_argument);
+    TS_ASSERT_THROWS(registry.subscribe<StubAlgorithm>(FileLoaderRegistry::NonHDF), std::runtime_error);
     TS_ASSERT_EQUALS(1, registry.size());
+
+    // We can't mock the factory as it's a singleton so make sure we clean up
+    Mantid::API::AlgorithmFactory::Instance().unsubscribe("StubAlgorithm", 1);
   }
 
-  void test_Finding_A_Loader_Throws_Invalid_Argument_If_Filename_Does_Not_Point_To_Valid_File()
+  private:
+  // Stub algorithm for test
+  struct StubAlgorithm : Mantid::API::Algorithm
   {
-    FileLoaderRegistry registry;
-
-    TS_ASSERT_THROWS(registry.findLoader(""), std::invalid_argument);
-    TS_ASSERT_THROWS(registry.findLoader("__notafile.txt__"), std::invalid_argument);
-  }
+    const std::string name() const { return "StubAlgorithm"; }
+    int version() const { return 1; }
+    void init() {};
+    void exec() {};
+  };
 
 };