Change Tracking Functions: What is Number of RTYPE_CMDNAME resource

Question

MS CE, Update 15, Language: C++

This question concerns using of change tracking functions. Callback function is set as follows:

ChangeTrack::AddChangedFunction (myChangeTrackFunc)

Signature of myChangeTrackFunc is:

void ChangeTrackFunc_Changed(  MSElementDescrP newDescr, 
                               MSElementDescrP oldDescr, 
                               DgnPlatform::ChangeTrackInfo *info, 
                               bool *cantBeUndoneFlag)

Argument DgnPlatform::ChangeTrackInfo *info is declared as follows (in ITxnManager.h):

struct ChangeTrackInfo
{
    ChangeTrackAction    action;            //!< type of action
    Int32                processNumber;     //!< process active at time of entry
    Int16                funcname;          //!< Number of RTYPE_CMDNAME resource.
    Int32                idNumber;          //!< id for grouping undos
};

My question relates to structure member funcname. It is described as: Number of RTYPE_CMDNAME resource.

What does that mean ??? Where do I get this requested command number from ???

Background:
In my code I'm using several MicroStation commands to modify existing MicroStation elements (like : trim extend, trim tointersection, etc.)
Each element modified by one of these MicroStation commands has to be processed by my callback function myChangeTrackFunc
depending on the MicroStation command which has modified the current element.

So my callback function would look as something like this:

void yourChangeTrackFunc (MSElementDescrP newDescr, 
                          MSElementDescrP oldDescr, 
                          DgnPlatform::ChangeTrackInfo *info, 
                          bool *cantBeUndoneFlag)
{
  switch (info->action)
  {
    case ChangeTrackAction::Modify:
    {
      // Element modified
      switch info->funcname:
      {
        case <Number of RTYPE_CMDNAME resource MS Cmd: Trim Extend>:
        {
          ...
        }
        break;
        case <Number of RTYPE_CMDNAME resource MS Cmd: Trim ToIntersection>:
        {
          ...
        }
        break;
        ... more MS Commands
      }
    }
    break;
  }
}

Any hints are appreciated. Thanks.

Martin Gitschel

Robert Hook · Answer

Hi Martin Gitschel , 
 There are a couple different API areas to review/evaluate to decide what may be best to implement based on your unique needs. 
 
 Input Queue - Monitors to Accept, Reject, or Replace MicroStation (user and app) input queue element commands 
 Change Tracking - Notifications of Transactional Changes that an app can choose to react to Element and Undo, Redo changes, that depend on uniquely qualified: Session Task Sequence (think PID), Task Tool/CommandId (Tool name or 64-bit Command Id) and Optional Command Args entries. 
 
 If your application has need to filter/prevent certain command(s), the input queue is best to implement filtering based on knowing: Task Name + CommandId criteria. 
 If your application has interest in the elements modified by a particular Task + CommandId; change tracking can be utilized. See Code Snippet: C++ ChangeTrackChanged that will help provide those missing details for *many* Command items not listed in: ..\Include\Mstn\cmdlist.r.h . 
 NOTE: Although there is mention to RTYPE_CMDNAME, it may be best to think of this as a "Tool Name" entry convention and the code snip above provides a shortcut on how to extract the tool name that can become more involved using the RTYPE_CMDNAME ID provided in ChangeTrackChanged event arg. 
 HTH, Bob

Change Tracking Functions: What is Number of RTYPE_CMDNAME resource

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