2011

There are two methods for redefining a block definition:
■ Modify the block definition in the current drawing.
■ Modify the block definition in the source drawing and reinsert it into the
current drawing.
The method you choose depends on whether you want to make changes in
the current drawing only or in a source drawing also.
Modify a Block Definition in the Current Drawing
To modify a block definition, follow the procedure to create a new block
definition, but enter the name of the existing block definition. This replaces
the existing block definition, and all the references to that block in the drawing
are immediately updated to reflect the new definition.
To save time, you can insert and explode an instance of the original block
and then use the resulting objects in creating the new block definition.
Update a Block Definition That Originated from a Drawing File
Block definitions created in your current drawing by inserting a drawing file
are not updated automatically when the original drawing is modified. You
can use INSERT to update a block definition from the drawing file.
Update a Block Definition That Originated from a Library Drawing
(Advanced)
Content palette does not overwrite an existing block definition in a drawing
with one that comes from another drawing. To update a block definition that
came from a library drawing, use WBLOCK to create a separate drawing file
from the library drawing block. Then, use INSERT to overwrite the block
definition in the drawing that uses the block.
NOTE Block descriptions are stripped off when using INSERT. Use the Clipboard
to copy and paste a block description displayed in the Define Block dialog box
from one block definition to another.
Redefine Block Attributes
You can attach attributes to a block when you define or redefine that block.
When you are prompted to select the objects to include in the block definition,
include the desired attributes in the selection set. Redefining the attributes in
432 | Chapter 21 Create and Modify Blocks