topic Determining source drawing and entity handle in ObjectARX Forum

Determining source drawing and entity handle

Anonymous — Thu, 16 Jan 2003 15:28:14 GMT

Is it possible to derive the source drawing name and entity handle from an
entity that appears in a drawing query in AutoCAD Map. If so, I would be
very grateful if someone could tell me the procedure.

Re: Determining source drawing and entity handle

Anonymous — Fri, 17 Jan 2003 03:11:38 GMT

On Thu, 16 Jan 2003 15:28:14 -0800, "awendle"
wrote:

>Is it possible to derive the source drawing name and entity handle from an
>entity that appears in a drawing query in AutoCAD Map. If so, I would be
>very grateful if someone could tell me the procedure.
>
>
You can use AcMapProject::GetSourceDrawingId to get the MAP-ID of the
source drawing.

Here is a sample code on how to do it. NB! You need to add some error
checking!!!

// Anders
--
void TEST()
{

AcMapAttachedDrawing *pDwg = NULL;
AcMapSession *mapApi = NULL;
AcMapProject *pProj = NULL;
AcMapDrawingSet *pDSet = NULL;
char *pcPath;
ads_name ss,e;
AcDbObjectId objId;
AcDbObject *pObj;

mapApi = AcMapGetSession();
mapApi->GetProject(pProj);
pProj->GetDrawingSet(pDSet);

int rc = acedSSGet(":S",NULL,NULL,NULL,ss);
if(rc==RTNORM)
{
acedSSName(ss,0,e);
acdbGetObjectId(objId,e);
pObj = NULL;
acdbOpenObject(pObj,objId,AcDb::kForRead);
if(pObj)
{
AcMapId mapId;
AcMap::EErrCode
eerr=pProj->GetSourceDrawingId(mapId,objId);
if(eerr==AcMap::kOk)
{
AcMapAttachedDrawing *pDwg=NULL;
// NB! MUST be NULL else we get all kind of strange errors!
pDSet->GetDrawing(pDwg,mapId);
pDwg->GetActualPath(pcPath);
acutPrintf("This entity is queried
from %s\n",pcPath);
delete []pcPath;
delete pDwg;
}
pObj->close();
}
}
}

Re:

Anonymous — Fri, 17 Jan 2003 17:27:11 GMT

That's great! Thanks a lot!

Do you know if there is any way to obtain the original entity handle from
the source drawing? The documentation states that the AcMapObjectId is
persistent across database load and unload operations, but I guess I don't
understand how to use it, because they don't appear to persist.

Thanks again,

"Anders M Eriksson" wrote in
message news:fhmf2v4s9ns5ur7rop7j2q4vfpl7fn83u0@4ax.com...
> On Thu, 16 Jan 2003 15:28:14 -0800, "awendle"
> wrote:
>
> >Is it possible to derive the source drawing name and entity handle from
an
> >entity that appears in a drawing query in AutoCAD Map. If so, I would be
> >very grateful if someone could tell me the procedure.
> >
> >
> You can use AcMapProject::GetSourceDrawingId to get the MAP-ID of the
> source drawing.
>
> Here is a sample code on how to do it. NB! You need to add some error
> checking!!!
>
> // Anders
> --
> void TEST()
> {
>
> AcMapAttachedDrawing *pDwg = NULL;
> AcMapSession *mapApi = NULL;
> AcMapProject *pProj = NULL;
> AcMapDrawingSet *pDSet = NULL;
> char *pcPath;
> ads_name ss,e;
> AcDbObjectId objId;
> AcDbObject *pObj;
>
>
> mapApi = AcMapGetSession();
> mapApi->GetProject(pProj);
> pProj->GetDrawingSet(pDSet);
>
> int rc = acedSSGet(":S",NULL,NULL,NULL,ss);
> if(rc==RTNORM)
> {
> acedSSName(ss,0,e);
> acdbGetObjectId(objId,e);
> pObj = NULL;
> acdbOpenObject(pObj,objId,AcDb::kForRead);
> if(pObj)
> {
> AcMapId mapId;
> AcMap::EErrCode
> eerr=pProj->GetSourceDrawingId(mapId,objId);
> if(eerr==AcMap::kOk)
> {
> AcMapAttachedDrawing *pDwg=NULL;
> // NB! MUST be NULL else we get all kind of strange errors!
> pDSet->GetDrawing(pDwg,mapId);
> pDwg->GetActualPath(pcPath);
> acutPrintf("This entity is queried
> from %s\n",pcPath);
> delete []pcPath;
> delete pDwg;
> }
> pObj->close();
> }
> }
> }
>
>

Re:

Anonymous — Mon, 20 Jan 2003 04:29:57 GMT

On Fri, 17 Jan 2003 17:27:11 -0800, "awendle"
wrote:

>That's great! Thanks a lot!
>
You're welcome!

>Do you know if there is any way to obtain the original entity handle from
>the source drawing? The documentation states that the AcMapObjectId is
>persistent across database load and unload operations, but I guess I don't
>understand how to use it, because they don't appear to persist.
>

Quote from the MAP help file:

"The AcMapObjectId class stores the object handle and the Id of the
source drawing that the object belongs to, so it is suitable for
identifying an AutoCAD object within an AutoCAD Map editing session
when AutoCAD Map might temporarily unload the drawing databases."

This I think means that the AcMapObjectId is only persistent in the
current Map Editing session! If you select an entity and get its
AcMapObjectId and then unloads the source drawing and do something and
then load the source drawing again. Then the entity will have the same
AcMapObjectId. It will not have the same AcDbObjectId.

I don't think that you can get the AcMapObjectId and use it in an
another Map Editing session!

What are you trying to do?

// Anders

Re:

Anonymous — Mon, 20 Jan 2003 11:34:10 GMT

> This I think means that the AcMapObjectId is only persistent in the
> current Map Editing session! If you select an entity and get its
> AcMapObjectId and then unloads the source drawing and do something and
> then load the source drawing again. Then the entity will have the same
> AcMapObjectId. It will not have the same AcDbObjectId.
>
> I don't think that you can get the AcMapObjectId and use it in an
> another Map Editing session!

I think you must be right about that.

> What are you trying to do?

It's a little complicated to explain, but I'll be as brief as possible:

The application I'm working on communicates with another process. This
other process is a database application based on "Progress." It generates
link IDs which are assigned to AutoCAD entities so that the application can
later find the entity to update it if a change is made in the database
application. If the entity handle persisted, it would be an easy matter to
store it and use it to go directly to the entity and update it.

Without it, the only way that I can see to get back to the entity is by
storing an ID as Object Data or an XRecord, do a query by object data (very
SLOW when the source drawings contain hundreds of thousands of entities) or
examine each entity on the source drawing until I find the one containing
the ID that I'm looking for. (Also very slow with this many entities.)

Thanks for your help.

Re:

Anonymous — Tue, 21 Jan 2003 02:42:50 GMT

On Mon, 20 Jan 2003 11:34:10 -0800, "awendle"
wrote:

>> What are you trying to do?
>
>It's a little complicated to explain, but I'll be as brief as possible:
>
>The application I'm working on communicates with another process. This
>other process is a database application based on "Progress." It generates
>link IDs which are assigned to AutoCAD entities so that the application can
>later find the entity to update it if a change is made in the database
>application. If the entity handle persisted, it would be an easy matter to
>store it and use it to go directly to the entity and update it.
>
>Without it, the only way that I can see to get back to the entity is by
>storing an ID as Object Data or an XRecord, do a query by object data (very
>SLOW when the source drawings contain hundreds of thousands of entities) or
>examine each entity on the source drawing until I find the one containing
>the ID that I'm looking for. (Also very slow with this many entities.)
>
Ok! I have done this in a couple of applications and I have used the
XData approach. i.e. I create an XData which contains the ID and then
loop though the drawing whenever I need to do anything to a specific
ID. It takes sometime but when the User considers how long time this
did take before (when he didn't have my application) then he is very
happy 😉

There is another possibility, I think. In AutoCAD you have CAO, which
is Database Connection ActiveX Object, i.e. how to connect autocad
entities with a database. It should be possible to use this in you
application, but I'm not sure how ...

I'm a bit busy at the moment, so I can't investigate any further in a
couple of weeks. If you come up with something I am interested!!

// Anders

Re:

Anonymous — Fri, 24 Jan 2003 01:48:14 GMT

Anders M Eriksson wrote in message
news:cd8q2vsiig88lgsfn0rook5olod79r0bhm@4ax.com...

> >Without it, the only way that I can see to get back to the entity is by
> >storing an ID as Object Data or an XRecord, do a query by object data
(very
> >SLOW when the source drawings contain hundreds of thousands of entities)

so you're saying arx entities dont' have persistent handles like in lisp or
vb(a)?
sorry i'm just an arx neophyte.

Re:

Anonymous — Mon, 27 Jan 2003 05:57:38 GMT

On Fri, 24 Jan 2003 01:48:14 -0800, "MP" wrote:

>
>Anders M Eriksson wrote in message
>news:cd8q2vsiig88lgsfn0rook5olod79r0bhm@4ax.com...
>
>> >Without it, the only way that I can see to get back to the entity is by
>> >storing an ID as Object Data or an XRecord, do a query by object data
>(very
>> >SLOW when the source drawings contain hundreds of thousands of entities)
>
>so you're saying arx entities dont' have persistent handles like in lisp or
>vb(a)?
>sorry i'm just an arx neophyte.
>
There are no Arx entities, just as there aren't any Lisp or VBA
entities. There are just entities.

The problem with entity handles are that they are generated when you
create them. This means that if you insert a drawing into another
drawing all entities in the first drawing will get new handles. So
when the user wants to shrink the drawing size and use wblock, all
entity handles are recreated!!

When it comes to Autodesk MAP, which is a separate AutoCAD product,
you always insert the entities in a new drawing. This is what's known
as doing a query. This of cause leads to that all entitys gets new
handles every time...

Hope this will help!

// Anders