[odb-users] BaseDaoEnabled for ODB

[علی دانش]

Hi Boris,
Is there a feature in ODB similar to 'Class BaseDaoEnabled' in OrmLite?
(http://ormlite.com/javadoc/ormlite-core/com/j256/ormlite/misc/BaseDaoEnabled.html)
I need this feature in my project, I changed the odb code to add this feature. It works up to now and I have not any problem yet, but I am not sure is it a good solution or not? Is it possible for you to review it and inform me about possible problems in it?
Steps to add this feature:

1-      Add 'BaseDaoEnabled .hxx':
#ifndef ODB_BASEDAOENABLED_HXX
#define ODB_BASEDAOENABLED_HXX
namespace odb
{
   // Base of odb objects and views:
   class BaseDaoEnabled
   {
      template <typename T, bool isBaseDaoEnabled> friend struct SetDaoEnabled;
   public:
      inline database* getDB() const { return db_; };
   protected:
      inline void setDB(database* db){ db_ = db; };
   private:
      database* db_ = nullptr;
   };
   template <typename T, bool = std::is_base_of<BaseDaoEnabled, T>::value> struct SetDaoEnabled
   {
      static inline void setDB(T*, odb::database*) {}
   };
   template <typename T> struct SetDaoEnabled < T, true >
   {
      static inline void setDB(T*, odb::database*);
   };
   template <typename T> /*static*/ inline void SetDaoEnabled<T, true>::setDB(T* p, odb::database* db)
   {
      p->BaseDaoEnabled::setDB(db);
   }
}
#endif //ODB_BASEDAOENABLED_HXX

2-      odb\forward.hxx, Line 174 (before #include <odb/post.hxx>) add:

a.  #include "odb/BaseDaoEnabled.hxx"

3-      odb\no_id_object_result.hxx, Line 17, change (a to b):

a.  pointer_type p (object_traits::create ());

b.  pointer_type p (object_traits::create (&db_));

4-      odb\simple-object-result.txx, Line 25, change (a to b):

a.       p = object_traits::create ();

b.      p = object_traits::create (&db_);

5-      odb\view_result.txx, Line 18, change (a to b):

a.       pointer_type p (view_traits::create ());

b.      pointer_type p (view_traits::create (&db_));

6-      odb\traits.hxx

a.  Line 44 & 60 & 76, change (i to ii):

                                                               i.   create ()

                                                               ii.   create (odb::database* db = nullptr)

b.      Line 48 & 64, change (i to ii):

                                                               i.      return pointer_factory<T, P>::create ();

                                                             ii.      return pointer_factory<T, P>::create (db);

c.       Line 81, add:

                                                               i.      SetDaoEnabled<T>::setDB(p, db);

7-      Generated file "%(Filename)-odb.cxx"; replace (a) with (b) by using a tool after running odb.exe:

a.       access::object_factory<object_type, pointer_type>::create ()

b.      access::object_factory<object_type, pointer_type>::create (&db)
That’s it. And now I can easily access to db in my models if they are inherited from odb::BaseDaoEnabled. If the model is not inherited from odb::BaseDaoEnabled all things happens like before. In my project each instance of my model may be from different sqlite database and in the model I need to access to db for example to do a query or load another related object and so on.
Best regards,
Ali