AllAccepted answers
Evgeny Shvarov · May 26, 2017

Thanks, Dan!

That definitely makes sense.

What I like about object callbacks is the code readability. Compare:

Method %OnBeforeSave(insert as %Boolean) As %Status [ Private, ServerOnly = 1 ]

{

if insert s ..CreationDate=$H

q $$$OK }

And 

Property CreationDate As %TimeStamp [ SqlComputeCode = { set {*}=$zdt($h,3) }, SqlComputed, SqlComputeOnChange = %%INSERT ];

What if I would need to refer to other properties in

{*)=expression()

Or the expression would be complex and if I want to debug it?

Is there a way to keep callbacks readability and have the callback methods  be fired for object and SQL access both?

Something like:

Property CreationDate As %TimeStamp [ SqlComputeCode = { set {*}=..%OnBeforeSave(1) }, SqlComputed, SqlComputeOnChange = %%INSERT ];