Topic: Using VLA-ITEM

[jbuzbee]

Lee Mac.

Completely off topic here: is that you in our avatar??

jb

p.s. No, that's NOT me in my avatar . . .

[CAB]

Ooo, I've never seen it used in that way before...

At a first glance, without testing anything, I thought that vlax-erased-p just checked the erased flag of an object, so if an item never existed in a collection, then I would assume it would error out...

EDIT:

Code: [Select]

(GetItem (vla-get-layers *doc) "Lee")
; error: unable to get ObjectID: "Lee"


Thanks Lee, that answers my question. Looks like gile has a keeper there.

[Lee Mac]

Lee Mac.

Completely off topic here: is that you in our avatar??

jb

p.s. No, that's NOT me in my avatar . . .

Hey James,

No, not me in the avatar, but I do ride a CBR600F 

[hermanm]

Don't forget vlax-map-collection

Being as how this is LISP, one might expect vlax-map-collection to behave similar to mapcar, but noooo

Code: [Select]

;;vlax-map-collection returns the collection object, not a list
;;you must build the list yourself as a side effect (yuck!)
;;so here is a simple wrapper which is proper LISP, i.e. function returns a useful value

(defun map-collection (obj func / return)
(vlax-map-collection obj
  '(lambda (obj / )
      (setq return (cons (func obj) return))
   )
)
return
)

;;equivalent
(vlax-for item collection
  (setq return (cons (func item) return))
)


[Kerry]

and it's slower (well, marginally) as well as uglier

Code: [Select]

(defun getLockedLayers1 (/ layNames)
    (vlax-map-collection
        (vla-get-layers (vla-get-activedocument (vlax-get-acad-object)))
        '(lambda (x)
             (if (= (vla-get-lock x) :vlax-true)
                 (setq layNames (cons (vla-get-name x) layNames))
             )
         )
    )
    (reverse layNames)
)

(defun getLockedLayers2 (/ layNames)
    (vlax-for item (vla-get-layers (vla-get-activedocument (vlax-get-acad-object)))
        (if (= (vla-get-lock item) :vlax-true)
            (setq layNames (cons (vla-get-name item) layNames))
        )
    )
    (reverse layNames)
)
(benchmark '((getLockedLayers1)
                     (getLockedLayers2)
            )
)
;=> ("X_NoPlot" "x-T50" "x-T35" "x-T25")

Benchmarking [M.P. 2005 < revised kdub 2005>] ..........
Elapsed milliseconds for 128 iteration(s)/ relative Timing :

    (GETLOCKEDLAYERS1).....1703 / 1.0185 <slowest>
    (GETLOCKEDLAYERS2).....1672 / 1.0000 <fastest>

[CAB]

And what does this do for the time? 

Code: [Select]

(defun getLockedLayers1 (/ layNames)
    (vlax-map-collection (vla-get-layers (vla-get-activedocument (vlax-get-acad-object)))
        (function (lambda (x)
             (if (= (vla-get-lock x) :vlax-true)
                 (setq layNames (cons (vla-get-name x) layNames))
             )
         ))
    )
    (reverse layNames)
)

[Kerry]

Yep .. good point !!

Benchmarking [M.P. 2005 < revised kdub 2005>] ..........
Elapsed milliseconds for 128 iteration(s) / relative Timing :
    (GETLOCKEDLAYERS1).....1172 / 1.0559 <slowest> ;<<<< using  vlax-map-collection
    (GETLOCKEDLAYERS2).....1125 / 1.0135                   ;<<<< using  vlax-for
    (GETLOCKEDLAYERS3).....1110 / 1.0000 <fastest>  ;<<<< using (function(lambda ... in place of '(lambda ...  with vlax-map-collection


but it's still ugly  
... nah, it's not really