Attribute writes to non-opened drawings

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  Coinciding with the acquisition of VIA Development, Nate joined Autodesk in March of 2003 after a decade stint as an entrepreneur following a two-decade stint as a controls engineer and software applications developer at Owens-Corning. Nate is now the lead product architect for AutoCAD Electrical. He loves this stuff.

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  Attribute writes to non-opened drawings
  July 5, 2009, 08:57 PM Nate Holt

  This dovetails with the last posting... instead of Xdata writes, this one illustrates attribute writes... find/replace block insert attribute values on non-opened drawings.

  There is at least one other posting from a couple years ago ( ! ) that deals with this subject, but here we'll pull it together a bit more completely. We'll illustrate two little AutoLisp utilities... one that works on the active drawing only and employs straight, generic AutoLisp calls. The second will be a version that is meant to work on non-opened drawing files. It seems to test okay using AutoCAD Electrical 2008 through 2010. I did not test on other ACE versions, so exercise caution.

  The Scenario

  The example will be this... we want to post-process our electrical schematic drawings and look for block insert instances with attribute tag "COLOR". We examine the current value on the attribute. If it matches up with a short list of possible values, we map a new value to it and push this out to the attribute.

  For example, if we find attribute "COLOR" with a value of "R" (for "red"), we want to map a new value of "RD" and push it out to the block insert's COLOR attribute. If we find a value of "G" (for "green"), we want to map a new value of "GN" and push it out.

  The Straight AutoLISP version - active drawing only

  Here is the first version of the utility (below). It is designed to process the active drawing only. You APPLOAD the utility, launch it at the "Command:" prompt. It runs, makes the changes, and exits.

  (defun c:remap_color_attrval ( / ss en ix str target_attrnam maplst slen
                ben blknam enn edd oldval newval newedd hitattr hdl ed x)
    ; Process all block inserts on active drawing. Look for attribute
    ; named "COLOR". If found, check existing value and map new color
    ; value to it. Also adjust the attribute's text size a bit to
    ; accommodate the longer mapped attribute value (ex: change "R" to "RD"
    ; or change "B" to "BU")
    ;
    ; -- list mapping here --
    (setq target_attrnam "COLOR")
    (setq maplst (list
        (list "R" "RD") ; red
        (list "B" "BL") ; blue
        (list "A" "AM") ; amber
        (list "G" "GN") ; green
        (list "C" "CL") ; clear
        (list "W" "WT") ; white
    ) )
    ; -- main program starts here --
    (setq ss (ssget "_X" '((0 . "INSERT"))))
    (if (/= ss nil)
      (progn
        (setq slen (sslength ss)) ; number of entities in selection set
        (setq ix 0) ; use to index through the selection set list
        (while (< ix slen)
          (setq ben (ssname ss ix)) ; get next block insert instance
                                    ; from the selection set
          (setq ix (1+ ix)) ; increment index for next time
          ; Now look for target attribute tag. Can do this in either
          ; of two way... can use a call to look for the attribute on
          ; this block insert, or can do it the hard way and cycle
          ; through all stand-alone subentities of this block insert
          ; instance and look for the target attribute. Let's do it
          ; the hard way.
         
          ; Now cycle through its stand-alone subentities like attributes
          ; (this is not the same as cycling through the entities of the
          ; block definition itself)
          (setq hitattr nil)
          (if (setq enn (entnext ben)) (setq edd (entget enn)))
          (while (AND enn (not hitattr)
                          (/= (cdr (assoc 0 edd)) "SEQEND") ; end of this entity
                          (/= (cdr (assoc 0 edd)) "INSERT") ) ; beginning of next!
            (if (= (cdr (assoc 2 edd)) target_attrnam)
              (progn ; yes, found target attribute tag
                (setq oldval (cdr (assoc 1 edd)))
                (setq hitattr 1) ; remember that we've found target attribute
                             ; so we can exit out of the "while" loop
                             ; sooner rather than later.
                ; Look for this target value in the map list
                (setq newval nil) ; use as flag to remember if mapped value hit
                (foreach x maplst
                  (if (= (car x) oldval)
                    (progn ; match on old attribute value
                      (setq newval (cadr x)) ; get the new mapped value
                ) ) )
                (if newval
                  (progn ; yes, found a new mapped value for this attribute
                    ; Prepare to push new value back out to the attribute
                    (if (setq newedd (subst (cons 1 newval)(assoc 1 edd) edd))
                      (progn
                        (entmod newedd) ; push new attribute value out
                        ; Display something to the command window
                        (setq ed (entget ben)) ; open the block insert instance
                        ; Get block name
                        (setq blknam (cdr (assoc 2 ed)))
                        ; Get handle
                        (setq hdl (cdr (assoc 5 ed)))
                        ; Display to command window
                        (princ "\nHDL=")(princ hdl)
                        (princ " BLKNAM=")(princ blknam)
                        (princ ", ")(princ target_attrnam)
                        (princ " old=")(princ oldval)
                        (princ ", new=")(princ newval)                                           
                    ) )
                ) )
            ) )
            (if (setq enn (entnext enn)) ; advance to next sub-entity of this
              (setq edd (entget enn)))   ; block insert instance
          )    
        ) 
        (setq ss nil) ; release the selection set
    ) )
    (princ)
  )        

  The above can be downloaded here:

  files/29401_29500/29471/file_29471.lsp - rename to remap_color_value.lsp. Appload it. Type remap_color_attrval [Enter] at the "Command:" prompt.
         

  The second version - meant to operate on non-opened drawing files

  This version parallels the one above but uses calls that are specific to AutoCAD Electrical (tested in ACE2008-2010 only). It is a bit longer and not reproduced here. Download a copy at this link:

  files/29401_29500/29481/file_29481.lsp - rename to remap_color_value_notactive.lsp. Appload it. Type remap_color_attrval_projectwide [Enter] at the "Command:" prompt.

  The advantage of this second version is that the processing can be done on multiple drawings without having to open each in turn.

   

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