Reactor labels

I am about to modify a routine I have that labels lines/polylines/arcs with
bearing and distances. I am going to make the labels dynamic so that if the
line is alteres, the label is realigned and the text value amended. I was
going to attached the handles of the text labels to the line as extended
data so that I can identify them when the reactor for the line kicks in. Is
this the only way to link the line and the text, or is there another method
associated with reactors where I can say which entities are affected when
the reactor is initiated?

Jon Rasmussen

My code for investigating Reactors:

(defun c:brdr ()
;attached reactor to line
(setq line (car (entsel "\nSelect Line ")))
(setq linereactor (vlr-object-reactor
(list (vlax-ename->vla-object line))
"Line Reactor" '(vlr-modified . updatebrgdst))
))
)
(defun updatebrgdst (notifier-object reactor-object parameter-list)
(vl-load-com)
(cond
(
(vlax-property-available-p
notifier-object
"length"
)
(princ "The length is ")
(princ (vla-get-length notifier-object))
)
)
(cond
(
(vlax-property-available-p
notifier-object
"angle"
)
(princ "The angle is ")
(princ (vla-get-angle notifier-object))
)
)
(princ)
)

 

hello,

Alternatively you can store related object in parameter-list of linereactor. Access it using (vlr-data linereactor).

regards,
Vaidas Guogis
www.kitox.com

 

Vaidas

This is not recommendable...
The Xdata is necessary to 'restore' the object reactors on startup of saved
drawings (except persistent reactors).

Cheers

 

The Xdata is necessary to 'restore' the object reactors on startup of saved
drawings (except persistent reactors).

Of course. I'm using both methods and persistent reactors too. Xdata requires more coding to restore relations, but it looks better to me. However, the question was about alternative.

regards,
Vaidas Guogis
www.kitox.com

 

If the line and text are both "owners" of the reactor, you can step through
the owner list to find the text object and then modify it.

Creating the reactor:

(setq line_reactor
(vlr-object-reactor
(list vlent vtent) ; note both the line (vlent) and text (vtent) are
owners...
"Line_Reactor"
'(vlr-modified . line_reaction)
vlr-erased . reactor_obj_erased))
)

)
(vlr-pers line_reactor) ; make it persistent

and in the reaction event (nname is the name of the notifier object and nobj
is the notifier object type):

(foreach xbj (print (vlr-owners reactorlist))
(setq oname (vlax-vla-object->ename xbj))
(if oname
(progn
(if (= (car (assoc 0 (entget oname))) "TEXT")
(if (= nobj "LINE") (text_update oname nname)))
)
)
)

 

Thank you everyone. Allen's solution looks like the way forward. I didn't
realise that the reactor could be tied to more than one object. The note
about persistent reactors is much appreciated also.

Thank you.

Jon Rasmussen

 

Another question, if I may trouble you further:
How do you determine if the object already has a reactor, and subsequently
remove the reactor so I can replace it with a new reference.
If I re-label the line, I need to re-associate the text to the reactor, and
the label text has xdata for how the label was derived (roundings and
alignment). So if the line is re-labelled, I would like to remove the
previous reactor.

I will look into vlr-owner-remove 'cause it sounds promising.

Thanks again,

Jon Rasmussen

 

here are two of my routines that i use hth:
hth - what a lovely understatement

Thank you Luis

Jon