Keep standard layers from being purged.

[mdhutchinson]

We have a set of standard layers and styles we wish to be in every file. Many users are purge happy. and the these standards many times get purged out.

I have a block I've created that holds all the standard styles and layers which I have turned to an anonymous block. I wish to stick this somewhere that would make it unpurgeable. I thought I'd find another block which normally cannot be purged and place my block inside, but am not certain which one would be best.

Any ideas as to where I might place this block to cause it to be un-purgeable?

[David_W_Koch]

Nothing is foolproof, but you could insert an instance of your block in your template file and then set its visibility property to off.  That would prevent the block from being erased by a "regular" user, the block definition from being purged, and, therefore, the layers and styles associated with the block.

A determined user with some basic customization skills, could still find the block and delete it, presumably such a user would understand why things set up that way and leave them alone.

[mdhutchinson]

I tried this... I placed the block on the Defpoints layer and turned it into anonymouse block and set its Explodable and Visible properties to false. We'll see how this flies.

I did at one point understand that you should not place intentional objects on layer defpoints...

Anyone have any thoughts?

[David_W_Koch]

I generally try to avoid using Defpoints for anything other than what AutoCAD uses it for, but we have a lot of people who still have not learned on a functional level that other layers can be designated as non-plotting and draw Viewports and all sorts of guidelines or other reference geometry on Defpoints.

You could put your block on Layer 0 or on one of the layers defined in the block, if you would rather not use Defpoints.

[mdhutchinson]

This is AutoCAD MEP here... I tried using an anonymous block as was suggested. I thought of another option...  Alternatively, we don't use several of the Architectural object type... like, windows, doors, curtain walls and stairs. So I've experimented with putting my standard text and dimension styles that I don't want purged in several of the Standard Stair style's Plan Display Representations Display Properties.

What about this?

More thoughts here in the MEP forum...

http://forums.autodesk.com/t5/AutoCAD-MEP/Keeping-standard-items-from-being-purged/td-p/4455845

[David_W_Koch]

I should have thought of that sooner - including a layer in a Display Representation will prevent it from being purged by the PURGE command alone.  Even if you used all of the architectural object, you could copy one or more Display Representations (Walls might be a good choice since there are quite a few display components to which layers could be assigned) that you do not intend for actual use, just as a place to reference a layer.  You might even add a Display Representation Set to referenced those Display Representations, to make it more difficult to purge the added Display Representation Sets.  I probably would not add a Display Configuration to reference the Display Representation Set, since that would be visible to the "casual" end user through the Display Configuration control on the Drawing Window Status Bar.

As with any of these methods, a determined and knowledgeable user will be able to delete the unreferenced Display Represenation Set, then unreferenced Display Representations and finally the layers, once she or he works out where the layers were referenced.  The invisible anonymous block is probably harder to find, but either method should work to prevent the purging of layers by someone using the PURGE command in a non-surgical manner.

[mdhutchinson · Accepted solution]

OK... This is what I ended up doing.

I created a block with text, dims, leader etc. that reference all the standard styles and layers for annotation. I added the block to the Curtain Wall Standard Style's, Model Display Rep as a Custom Model Component. This way the 'whole' is prevented from being purged within this single location.

[chauhuh]

Alternatively you could redefine the purge command to reimport the needed items at the end of the purge. Lee Mac's steal lisp would be good for this.