API: Re-Attaching to entities created programatically.

A question on methods for doing this. The situation.

You create a program or macro to help in some of the more cumbersome
detailing tasks say unconventional or custom ballooning. Is there a way to
flag items added by a program so they can be found the next time the program
is run. I have used Naming in the past but feel it is lacking. I know that
with AutoCAD you can add Extended data to an object that allows you to
attach your program name and custom properties. What have you found to be
the best way? If you do use naming conventions as I have what logic do you
use in the name of the object.

Corey

 

Seems to me that in the API part of Support there is some discussion of
saving user data with parts and features.

 

This is the type of situation that Persistent References is intended to
address. While the SelectByID is name-based, it is really finicky
about case-sensitivity and changes to the instance #. I've noticed
that SW2004 and later sometimes re-numbers the instances when some of
the instances are deleted or suppressed. This messes up the SelectByID
call. The API Help file includes an example of getting Persistent Refs
and then using them to gain access to those objects in a later SW
Session. One limitation of the Persistent Refs is that they seem to
change if a document is copied and re-named.

On another tact, you can programatically define and add "Attributes" to
individual entities and features. They can then be traversed and read
programatically. This is probably closest to what you were describing
as "Extended data" that you can customize for individual features. One
caveat to using Attributes is that SW has a policy of controlling the
3-letter pre-fix used in the Attribute name. Anyone can use "pub" (for
public) as a prefix, but if you distribute your program to others, you
should request your own unique prefix from SW. The reason for this is
to avoid the nasty situation of 3rd party products over-writing each
other's attributes. This could be a very confusing situation to
troubleshoot since attributes are often stored invisible to the user.

Hope this gives you a few more alternatives to consider.

Best regards,
Brenda
CustomSolids