Topic: 2 block inserts. Same name blocks. One with attributes, one without... HOW?

[Eddie D.]

The attached drawing has two inserts of the same block. One insert has attributes. The other does not. How is this possible?
Explode the attributed one, the attritute definitions disappear.
Redefine the block with no attributes, the attributes remain.
What the heck?
In my 30 years of AutoCAD usage, I've never seen this.

[Rob...]

I'm thinking the block was redefined without the attributes. I cannot figure out why ATTSYNC won't work though.

[Eddie D.]

Rob, it looks like that may just be culprit. In another drawing, I redefined an attributed block without the attributes and got the same result with a block that still has attributes. Attsync does nothing, doesn't even recognize any blocks with attributes. I can still edit the attributes, though.
Weird... I've never seen this before. I guess it's just something I've never done before (the drawing with the issue was not created by me).


Thanks for looking.

[MP]

Attributes can easily be added during block instancing (independent/contrary to the block def'n) and can be deleted post instancing.

[mjfarrell]

yep


those two blocks are not the same


the original most likely had attributes,

then they were removed

thus attsync wont work because the parent block definition has no attributes defined.

A simple wblock of the block with attributes yields a drawing with no attributes. (symptom)

There are no attributes within the original block definition (diagnosis)

[Jeff H]

When you insert a block it looks to see if it contains any attribute definitions in the block definition and if it does then it creates attribute references then translates them and are part of the block reference.

If you think about it there is no way attributes could be part of the block definition because the attributes could not vary.

So attribute references are part the block reference and have nothing to do with definition just use it as template.

If a block contains no attributes ATTSYNC will not erase attribute references, but if add one attribute definition to block definition and then do ATTSYNC, then remove the attribute you just added to definition and ATTSYNC again it will remove all of them.

[Rob...]

When you insert a block it looks to see if it contains any attribute definitions in the block definition and if it does then it creates attribute references then translates them and are part of the block reference.

If you think about it there is no way attributes could be part of the block definition because the attributes could not vary.

So attribute references are part the block reference and have nothing to do with definition just use it as template.

If a block contains no attributes ATTSYNC will not erase attribute references, but if add one attribute definition to block definition and then do ATTSYNC, then remove the attribute you just added to definition and ATTSYNC again it will remove all of them.

Nice explanation.

[mjfarrell]

Interesting thing to note, if you either

edit the block(that appears to have attributes) in block  editor

or edit in place

The 'attributes' do not show up in the block editor, nor can you select them as part of the block/nested items to be edited.

[T.Willey]

Michael,

That makes sense since those commands most likely look at the block definition, and since the attributes were added to the insert (not the block definition) then the definition would know nothing of what has happened to an insert.

One can use the code at the link to add attributes to any 'insert'.  This means you could create thousands of inserts that all have different amounts of attributes.

https://www.theswamp.org/index.php?topic=8037.msg426208#msg426208

[mjfarrell]

Michael,

That makes sense since those commands most likely look at the block definition, and since the attributes were added to the insert (not the block definition) then the definition would know nothing of what has happened to an insert.

One can use the code at the link to add attributes to any 'insert'.  This means you could create thousands of inserts that all have different amounts of attributes.

https://www.theswamp.org/index.php?topic=8037.msg426208#msg426208

I know that you can, however as a matter of practice WHY would you introduce such randomness to a drawing?
Seems like an excellent example of; just because one can, doesn't mean you should.

[T.Willey]

I use it sometimes.  Just to add more information to a block and keep all the information associated together.  To each their own.

[danallen]

sometimes it's by accident - for example I'll make a block, insert it a few times, then decide I need to add some or additional attributes. I'll update definition but not get around to reinserting all the old inserts to include the attributes.

[Rod]

Unfortunately this is something I have to correct often, I use these steps (this is from memory)
1. Attout
2. Redefine Block with a correct version
3. Fix CSV (from attout) column headings, delete unnecessary columns and ensure columns are in the right order
4. attsync
5. attin

Cheers, Rod.