Over the years there have been several different and disparate ways of managing directories in OpenInsight, and not all of them fully documented. In this post we’re going to take look at the “official” preferred methods, along with a mention of the deprecated ones too.

Preferred methods

• The FILESYSTEM object (for Event Context)
• RTI_OS_Dir stored procedure (for non-Event Context)

Deprecated methods

• Utility stored procedure
• RTI_OS_Directory stored procedure
• DirExists stored procedure
• MkDir stored procedure
• UtilityMakeDir stored procedure
• UtilityRemoveDir stored procedure
• UtilityRename stored procedure

A note on directory management and context

As you may be aware, an OpenInsight application runs in one of the following contexts:

• Event Context – This applies when your Basic+ programs are called in response to an event from a standard OpenInsight application form or control (i.e. an application managed by the Presentation Server).
• Non-Event Context – This applies to applications that run Basic+ programs outside of the Presentation Server using the RevCAPI interface to manage an instance of RevEngine. These are usually “Inet” or O4W web applications, but also include other methods like the RevRun.exe program too.

Therefore, one of the most fundamental considerations when choosing which directory management method to use is the context in which it is called: As a rule, when running in Event Context, you should always prefer to use the FILESYSTEM object for directory management, otherwise you should choose the RTI_OS_Dir stored procedure instead.

Note that if there is a possibility that your Basic+ programs will be executed in different contexts at runtime (i.e. you share them between contexts) then you should invoke the IsEventContext stored procedure to determine which method to use.

For example, here is a simple context-aware code snippet that removes a directory:

   Declare Function IsEventContext, RTI_OS_Dir, Exec_Method
   $Insert PS_FileSystem_Equates
   $Insert RTI_SSP_Equates
   
   ErrText = ""

   If IsEventContext() Then
      // Use the FILESYSTEM object
      If Exec_Method( "FILESYSTEM", "REMOVEDIR", DirName ) Else
         ErrInfo = Get_Property( "FILESYSTEM", "FILEOPRESULT" )
         ErrCode = ErrInfo<PS_FOR_ERRORCODE$>
         ErrText = ErrInfo<PS_FOR_ERRORTEXT$>
      End
   End Else
      // Use RTI_OS_DIR
      Call Set_Status( SETSTAT_OK$ )
      If RTI_OS_Dir( "REMOVEDIR", DirName ) Else
         Call Get_Status( ErrText )
      End
   End

Using the FILESYSTEM object

The FILESYSTEM object supports the following methods to manage directories. It integrates fully with the Windows Shell and provide the best user experience in Event Context:

• COPYDIR
• DIREXISTS
• GETSPECIALDIR
• MAKEDIR
• MOVEDIR
• REMOVEDIR
• RENAMEDIR

The FILESYSTEM object is fully documented here.

Using the RTI_OS_Dir stored procedure

This stored procedure was added to OpenInsight 10 to provide a non-Event Context version of the functionality exposed by the FILESYSTEM object. It supports the following methods:

• COPYDIR
• DIREXISTS
• GETTEMPDIR
• MAKEDIR
• MOVEDIR
• REMOVEDIR
• RENAMEDIR

The RTI_OS_Dir stored procedure is fully documented here.

(Note that there is no direct equivalent of the FILESYSTEM GETSPECIALDIR method, due to the fact that it is very Windows-specific – the GET_SPECIAL_FOLDER stored procedure should be used instead.)

The Utility stored procedure (Deprecated)

As long-time readers of this blog will know, this stored procedure was deprecated some years ago at the outset of the OpenInsight 10 project, and it is now basically a thin wrapper around several SYSTEM and FILESYSTEM object methods. It supports the following directory management methods:

• MAKEDIR
• REMOVEDIR
• RENAMEDIR

When called in Event Context each of these methods forwards the request to the FILESYSTEM object. When called outside of Event Context these methods call the following stored procedures instead:

• UtilityMakeDir
• UtilityRemoveDir
• UtilityRename

See below for more details on these.

The RTI_OS_Directory stored procedure (Deprecated)

This stored procedure was deprecated in favor of RTI_OS_Dir as it is very platform specific and makes use internally of RTI_OS_Dir, Utility, and an OLE interface to the Windows Shell, making it less performant than calling those procedures directly. Like Utility it is still supported but will not be updated further with any new functionality.

DirExists stored procedure (Deprecated)

This stored procedure is a simple wrapper around the RTI_OS_Dir DIREXISTS method and so has been deprecated, but can still be used by existing code.

MkDir stored procedure (Deprecated)

This venerable stored procedure is a DLL function that calls the Windows API CreateDirectory function. It has been deprecated in favor of the RTI_OS_Dir MAKEDIR method but can still be used by existing code.

UtilityMakeDir, UtilityRemoveDir and UtilityRename stored procedures (Deprecated)

These three functions form part of the original internals of the Utility stored procedure, and use a “raw” C interface that requires explicit null-terminated strings. They are all still available to use, but are deprecated in favor of the RTI_OS_Dir MAKEDIR, REMOVEDIR and RENAMEDIR methods.

Conclusion

As you can see, version 10 has pulled together the many different historical methods of directory management and consolidated them into two entities that can be used dependent on the execution context. These should be the preferred methods of directory management in your OpenInsight applications.

(As of the time of writing the full documentation for RTI_OS_DIR and GET_SPECIAL_FOLDER is in preparation and will be available shortly. All methods described here apply to version 10.2.3 and later.)

(EDIT: Full documentation for RTI_OS_DIR and GET_SPECIAL_FOLDER is now live on the Revelation Wiki.)