Can we change one of values of block reference with lisp?

Hi guys,

I have a block reference which has tags and their values and a location symbol, that is, a circle symbol, two texts, one is steel_1 (tag is material) and the other one is 3.25m (tag is depth). I want to select those blocks which have "steel_1" text and change to "steel_2" with lisp routine.
it seems we can't access the components of block references with Autolisp.
Maybe we can do this in other way, however I prefer lisp routine.
Any help or idea, lots of thanks!
San

You can access the block attributes using either Vanilla or Visual LISP, perhaps these functions will get you started:

http://lee-mac.com/attributefunctions.html

If the 'components' that you describe are Text Objects and not Attributes, you will instead need to iterate through the block definition.

Lee

You can access the block attributes using either Vanilla or Visual LISP, perhaps these functions will get you started:

 

http://lee-mac.com/attributefunctions.html

 

If the 'components' that you describe are Text Objects and not Attributes, you will instead need to iterate through the block definition.

 

Lee

Thank you very much for the reply.

I will start with the website. Do you have any clue to iterate through the block definition? or any directions to guide my study?

Thanks again,

San

Are you looking to modify text within a block, or attributes?

Are you looking to modify text within a block, or attributes?

to modify text within a block.

Thank you.

San

Consider the following function to iterate through the objects in the block definition and apply an arbitrary function to each object in turn:

[color=GREEN];;---------------=={ Apply to Block Objects }==---------------;;[/color]
[color=GREEN];;                                                            ;;[/color]
[color=GREEN];;  Applies a supplied function to all objects in a block     ;;[/color]
[color=GREEN];;  definition.                                               ;;[/color]
[color=GREEN];;------------------------------------------------------------;;[/color]
[color=GREEN];;  Author: Lee Mac, Copyright © 2011 - www.lee-mac.com       ;;[/color]
[color=GREEN];;------------------------------------------------------------;;[/color]
[color=GREEN];;  Arguments:                                                ;;[/color]
[color=GREEN];;  _acblocks  - block collection in which block resides      ;;[/color]
[color=GREEN];;  _blockname - name of block to apply function              ;;[/color]
[color=GREEN];;  _function  - function to apply to all objects in block    ;;[/color]
[color=GREEN];;------------------------------------------------------------;;[/color]
[color=GREEN];;  Returns: List of results of evaluating function, else nil ;;[/color]
[color=GREEN];;------------------------------------------------------------;;[/color]

([color=BLUE]defun[/color] LM:ApplytoBlockObjects ( _acblocks _blockname _function [color=BLUE]/[/color] result )
 (
   ([color=BLUE]lambda[/color] ( _function [color=BLUE]/[/color] def )  
     ([color=BLUE]if[/color]
       ([color=BLUE]not[/color]
         ([color=BLUE]vl-catch-all-error-p[/color]
           ([color=BLUE]setq[/color] def
             ([color=BLUE]vl-catch-all-apply[/color] '[color=BLUE]vla-item[/color] ([color=BLUE]list[/color] _acblocks  _blockname))
           )
         )
       )
       ([color=BLUE]vlax-for[/color] obj def ([color=BLUE]setq[/color] result ([color=BLUE]cons[/color] (_function obj) result)))
     )
   )
   ([color=BLUE]eval[/color] _function)
 )
 ([color=BLUE]reverse[/color] result)
)

Here is an example test function which will move all objects in a block to layer "0":

[color=GREEN];; Test Function to Move all Objects in a Block to Layer "0"[/color]

([color=BLUE]defun[/color] c:test ( [color=BLUE]/[/color] acdoc acblk ss l )

 ([color=BLUE]setq[/color] acdoc ([color=BLUE]vla-get-activedocument[/color] ([color=BLUE]vlax-get-acad-object[/color]))
       acblk ([color=BLUE]vla-get-blocks[/color] acdoc)
 )

 ([color=BLUE]if[/color] ([color=BLUE]setq[/color] ss ([color=BLUE]ssget[/color] [color=MAROON]"_+.:E:S"[/color] '((0 . [color=MAROON]"INSERT"[/color]))))
   ([color=BLUE]progn[/color]    
     (LM:ApplytoBlockObjects acblk ([color=BLUE]cdr[/color] ([color=BLUE]assoc[/color] 2 ([color=BLUE]setq[/color] l ([color=BLUE]entget[/color] ([color=BLUE]ssname[/color] ss 0)))))
       ([color=BLUE]function[/color]
         ([color=BLUE]lambda[/color] ( obj ) ([color=BLUE]vla-put-Layer[/color] obj [color=MAROON]"0"[/color]))
       )
     )
   )
 )
 ([color=BLUE]princ[/color])
)

[ Requires Regen after block definition modification ]

Lee

Consider the following function to iterate through the objects in the block definition and apply an arbitrary function to each object in turn:

 

[color=green];;---------------=={ Apply to Block Objects }==---------------;;[/color]
[color=green];;                                                            ;;[/color]
[color=green];;  Applies a supplied function to all objects in a block     ;;[/color]
[color=green];;  definition.                                               ;;[/color]
[color=green];;------------------------------------------------------------;;[/color]
[color=green];;  Author: Lee Mac, Copyright © 2011 - www.lee-mac.com       ;;[/color]
[color=green];;------------------------------------------------------------;;[/color]
[color=green];;  Arguments:                                                ;;[/color]
[color=green];;  _acblocks  - block collection in which block resides      ;;[/color]
[color=green];;  _blockname - name of block to apply function              ;;[/color]
[color=green];;  _function  - function to apply to all objects in block    ;;[/color]
[color=green];;------------------------------------------------------------;;[/color]
[color=green];;  Returns: List of results of evaluating function, else nil ;;[/color]
[color=green];;------------------------------------------------------------;;[/color]

([color=blue]defun[/color] LM:ApplytoBlockObjects ( _acblocks _blockname _function [color=blue]/[/color] result )
 (
   ([color=blue]lambda[/color] ( _function [color=blue]/[/color] def )  
     ([color=blue]if[/color]
       ([color=blue]not[/color]
         ([color=blue]vl-catch-all-error-p[/color]
           ([color=blue]setq[/color] def
             ([color=blue]vl-catch-all-apply[/color] '[color=blue]vla-item[/color] ([color=blue]list[/color] _acblocks  _blockname))
           )
         )
       )
       ([color=blue]vlax-for[/color] obj def ([color=blue]setq[/color] result ([color=blue]cons[/color] (_function obj) result)))
     )
   )
   ([color=blue]eval[/color] _function)
 )
 ([color=blue]reverse[/color] result)
)

Here is an example test function which will move all objects in a block to layer "0":

 

[color=green];; Test Function to Move all Objects in a Block to Layer "0"[/color]

([color=blue]defun[/color] c:test ( [color=blue]/[/color] acdoc acblk ss l )

 ([color=blue]setq[/color] acdoc ([color=blue]vla-get-activedocument[/color] ([color=blue]vlax-get-acad-object[/color]))
       acblk ([color=blue]vla-get-blocks[/color] acdoc)
 )

 ([color=blue]if[/color] ([color=blue]setq[/color] ss ([color=blue]ssget[/color] [color=maroon]"_+.:E:S"[/color] '((0 . [color=maroon]"INSERT"[/color]))))
   ([color=blue]progn[/color]    
     (LM:ApplytoBlockObjects acblk ([color=blue]cdr[/color] ([color=blue]assoc[/color] 2 ([color=blue]setq[/color] l ([color=blue]entget[/color] ([color=blue]ssname[/color] ss 0)))))
       ([color=blue]function[/color]
         ([color=blue]lambda[/color] ( obj ) ([color=blue]vla-put-Layer[/color] obj [color=maroon]"0"[/color]))
       )
     )
   )
 )
 ([color=blue]princ[/color])
)

 

[ Requires Regen after block definition modification ]

 

Lee

Thank you a lot, Lee.

It's hard to understand you code, but I keep trying to.

Thank you a lot, Lee.

It's hard to understand you code, but I keep trying to.

If it helps you needn't understand the 'LM:ApplytoBlockObjects' function, just know how to call it.