Adding Information to custom objects

[andreashafver]

Open in Wolfram Cloud ↗

[jasonb (Jason Biggs)]

I believe this is how it works.

Information`AddRegistry[MyObject, getMyObjectInformation];
getMyObjectInformation[MyObject[ass_?MyObjectQ]] := <|
  (* this first key is mandatory *)
  "ObjectType" -> "MyObject",
  (* next just include the whole inner association *)
  ass, 
  (* now define any computed properties using RuleDelayed *)
  "Length" :> Length[ass["List"]]
|>

And now it works as expected:

[andreashafver]

Great, thank you very much!