program abort with ESC

i wrote a lisp, where i have to set OSNAP to 2, if the user enters ESC
key, my program stopps and i have OSNAP set to 2, but i want to change
it back to the value it had at the beginn of my program

(setq OSNAPOLD (getvar "OSNAP"))
..
..
program
..
..
*if ESC ist pressed, stop program AND set OSNAP back to OSNAPOLD

any help welcome

mfg
gert

 

Do a search for "ESC error" in this discussion group and you'll get a wealth of information on this subject.

 

Gert,

What you are describing is an error handler. I'm not an expert at these, but I have put together several of them and mine work - other people may have better ideas, but for what it's worth, here's my 2 cents.

I used to write in an error handler into every program when I was just figuring out the concept, but now I place the code as a modularized function in my Acaddoc.lsp and call it in any routine. Also, Ive got a mode collector and reset-er in there too so now I just call (modes '("osmode" "snapmode" "osmode" "autosnap")) after the start of the defun, then I simply issue a (moder) at the end to return.

However, to get you started, here's the old way I used to do it.....
An example of using error handling - HTH This gets placed above the defun :

(DEFUN arwERR (msg) ;;; error handling function
(setq *error* olderr)
(command "UNDO" "E")
(command "u")
(resetvars-dbla)
(princ)
)
(defun catchvars-dbla ()
(setq RL (getvar "CLAYER")) ;;; store current layer
(setq asm (getvar "autosnap")) ;;; store autosnap settings
(setq orm (getvar "orthomode")) ;;; store current ortho status
(setq osm (getvar "osmode")) ;;; store current osnap modes
(setq ASZ (getvar "DIMASZ"))
(setq DSCL (getvar "DIMSCALE"))
)
(defun resetvars-dbla ()
(setvar "osmode" osm) ;;; reset osnap modes
(setvar "orthomode" orm) ;;; reset ortho to previous status
(setvar "autosnap" asm) ;;; reset autosnap to previous status
(setvar "clayer" rl) ;;; reset previous current layer
(setvar "plinewid" 0.0)
(setvar "DIMASZ" ASZ)
(setvar "DIMSCALE" DSCL)
(princ) ;;; quiet exit
)
Here's where your defun goes....
(defun c:blahblah blah ()
then immediately you issue your variable-catcher, error handler start and undo loop begining ... like this.....
(catchvars-dbla) ;;; collect current environment settings
(setq olderr *error* ;;; Use special error handling function in place of AutoCAD standard error.
*error* arwerr)
(command "UNDO" "be") ;;; begin undo loop (in case of undo or error)
Now your program guts go here....
( blah blah blah do this, do that...)
and the reset and undo close go as the last lines before your princ
(resetvars-dbla) ;;; reset the variables
(command "UNDO" "E") ;;; end undo marked area (making it one big step)
(PRINC) ;;; quiet exit
)

It may need some tweeking, but it works for me... HTH

 

Gert,

You want to use an error function like this assuming A2k or later.

(defun c:functionname ( / *error* local_vars)

(defun *error* (Msg)
(cond
((or (not Msg)
(member Msg '("console break"
"Function cancelled"
"quit / exit abort"))))
((princ (strcat "\nError: " Msg)))
) ;cond
;reset vars here
(setvar "osnap" OSNAPOLD)
(princ)
) ;end error

;; primary code starts here
(setq OSNAPOLD (getvar "OSNAP"))
;; code
;; at the end of code, call the error function:
(*error* nil)

The error handler will reset the osnap variable regardless of whether the user
cancels, or the program runs to completion.

Joe Burke

 

Rapidcad (do you have a *real* name? <bg>),

Your posted example works great for R14 and earlier, but starting with
AutoCAD 2000 it is possible to declare *error* as a local variable and have
it remain local when it runs. Joe's example shows a way to use the local
variable approach.

Also, you are basically duplicating code, once to handle a normal exit from
the program, and once for the error handler. Joe's example shows how adding
a test for a nil error message allows you to use the error handler to handle
a normal exit also, removing the need for duplicated code.

--
R. Robert Bell


Gert,

What you are describing is an error handler. I'm not an expert at these,
but I have put together several of them and mine work - other people may
have better ideas, but for what it's worth, here's my 2 cents.

I used to write in an error handler into every program when I was just
figuring out the concept, but now I place the code as a modularized function
in my Acaddoc.lsp and call it in any routine. Also, Ive got a mode
collector and reset-er in there too so now I just call (modes '("osmode"
"snapmode" "osmode" "autosnap")) after the start of the defun, then I simply
issue a (moder) at the end to return.

However, to get you started, here's the old way I used to do it.....
An example of using error handling - HTH This gets placed above the defun :

(DEFUN arwERR (msg) ;;; error handling function
(setq *error* olderr)
(command "UNDO" "E")
(command "u")
(resetvars-dbla)
(princ)
)
(defun catchvars-dbla ()
(setq RL (getvar "CLAYER")) ;;; store current layer
(setq asm (getvar "autosnap")) ;;; store autosnap settings
(setq orm (getvar "orthomode")) ;;; store current ortho status
(setq osm (getvar "osmode")) ;;; store current osnap modes
(setq ASZ (getvar "DIMASZ"))
(setq DSCL (getvar "DIMSCALE"))
)
(defun resetvars-dbla ()
(setvar "osmode" osm) ;;; reset osnap modes
(setvar "orthomode" orm) ;;; reset ortho to previous status
(setvar "autosnap" asm) ;;; reset autosnap to previous status
(setvar "clayer" rl) ;;; reset previous current layer
(setvar "plinewid" 0.0)
(setvar "DIMASZ" ASZ)
(setvar "DIMSCALE" DSCL)
(princ) ;;; quiet exit
)
Here's where your defun goes....
(defun c:blahblah blah ()
then immediately you issue your variable-catcher, error handler start and
undo loop begining ... like this.....
(catchvars-dbla) ;;; collect current environment settings
(setq olderr *error* ;;; Use special error handling function in place
of AutoCAD standard error.
*error* arwerr)
(command "UNDO" "be") ;;; begin undo loop (in case of undo or error)
Now your program guts go here....
( blah blah blah do this, do that...)
and the reset and undo close go as the last lines before your princ
(resetvars-dbla) ;;; reset the variables
(command "UNDO" "E") ;;; end undo marked area (making it one big step)
(PRINC) ;;; quiet exit
)

It may need some tweeking, but it works for me... HTH

 

Thanks R.
Your insight is from many years of experience I take it. Thanks for the advice. You've easily exposed the fact that this example of mine is old. It does in fact come from a ver. 12 application that still works flawlessly today (A2K4) As I said
" I'm not an expert at these, but I have put together several of them and mine work - other people may have better ideas, but for what it's worth, here's my 2 cents. "

I'll have to try again to get my hands around Joe's example. Since I first wrote this handler, I have figured out that my 3rd party app has an error handler built in so I've been using it.

It doesn't take much experience to know that my example is pretty antiquated, (and yes, clumsy). I replied to his query in the first place not because I have much to share, but because I figued I could help out some. I've been posting a question all week - today I posted it for the third time - and for the third time I've gotten 0 replies - even with 3 different titles, so I don't want that to happen to him. And partly, I'm hoping the old proverb, "he who refreshes others shall by others be refreshed" might come true for me.

And yes I do have a "real" name, it might even be the same as "R." (if I knew what that stood for) - thanks for asking...<g>

 

Sometimes we need to support older versions, which is why I said your code
is certainly valid for those cases. You have also indicated in the past a
willingness to learn new techniques, which why I pointed Joe's thread out to
you.

I've seen your other threads, but haven't had the time to do a heavy debug
on it. I had a migraine yesterday, which hosed me for the day.

--
R. Robert Bell


Thanks R.
Your insight is from many years of experience I take it. Thanks for the
advice. You've easily exposed the fact that this example of mine is old.
It does in fact come from a ver. 12 application that still works flawlessly
today (A2K4) As I said
" I'm not an expert at these, but I have put together several of
them and mine work - other people may have better ideas, but for what it's
worth, here's my 2 cents. "

I'll have to try again to get my hands around Joe's example. Since I first
wrote this handler, I have figured out that my 3rd party app has an error
handler built in so I've been using it.

It doesn't take much experience to know that my example is pretty
antiquated, (and yes, clumsy). I replied to his query in the first place
not because I have much to share, but because I figued I could help out
some. I've been posting a question all week - today I posted it for the
third time - and for the third time I've gotten 0 replies - even with 3
different titles, so I don't want that to happen to him. And partly, I'm
hoping the old proverb, "he who refreshes others shall by others be
refreshed" might come true for me.

And yes I do have a "real" name, it might even be the same as "R." (if I
knew what that stood for) - thanks for asking...<g>

 

Sorry to hear of the headaches, Robert. I do appreciate everything I get from this forum, and I try to answer the easier questions (when workload allows) since that's more my speed. Mark Propst did a huge favor and on his own initiave rewrote just about the whole thing in active X for me. It works pretty well now. As far as learning new things, I'll have to chew on the active X stuff for awhile! Thanks for your comments and all that you contriburte to us less experienced programmers....

Ron Powell
CAD Manager
jdh Engineering
Grandville, MI

 

Thanks Ron!

--
R. Robert Bell


Sorry to hear of the headaches, Robert. I do appreciate everything I get
from this forum, and I try to answer the easier questions (when workload
allows) since that's more my speed. Mark Propst did a huge favor and on
his own initiave rewrote just about the whole thing in active X for me. It
works pretty well now. As far as learning new things, I'll have to chew on
the active X stuff for awhile! Thanks for your comments and all that you
contriburte to us less experienced programmers....

Ron Powell
CAD Manager
jdh Engineering
Grandville, MI

 

thx for your answers, i will try it with the error function

mfg

gert