any idea how i could make delegated properties in ...

# spring

[nfrankel]

any idea how i could make delegated properties in kotlin work with jpa?

[sdeleuze]

JPA is setting directly private fields I think, so I don't think that will work.

[nfrankel]

😞

[nfrankel]

thanks

[thanksforallthefish]

I tried to use them and they don't really work. or it is weird, I will try today to create a sample repository with my findings

[nfrankel]

i abandoned this approach in favor of event listeners in hibernate

[thanksforallthefish]

and I now figure you probably meant delegated properties https://kotlinlang.org/docs/reference/delegated-properties.html, I mean the delegation pattern https://kotlinlang.org/docs/reference/delegation.html

[lex]

@nfrankel do you try @get:Column(...)?

[nfrankel]

@lex i didn’t

[lex]

@nfrankel try it and tell us 🙂

[nfrankel]

i just changed my code to use event listeners
i might do it but later
i’m too lazy atm

[nfrankel]

besides, i’m thinking that since i’m using constructor arguments
annotations are already on fields
and you cannot mix-and-match fields’ and getters’ annotations

[thanksforallthefish]

I think you need @field:annotation, otherwise kotlin puts the annotation on the constructor parameter

[thanksforallthefish]

Ar least, I had that case with validation and data classes

[lex]

I think is this case all mappings should be on getters

[nfrankel]

tbh, i didn’t use hibernate for a long time
and i remember that it was a good practice to put annotations on attributes
i don’t remember the reason, though 😅

[lex]

@thanksforallthefish @field does not help in this case, because fields physically do not represented in class with delegation

[masc3d]

have you looked into @EntityListeners?

[nfrankel]

i’m using spring, entity listeners cannot be injected by spring 😞
i’m using hibernate events directly

[masc3d]

true. we use eclipselink events directly 🙂

[masc3d]

looking at weaved jpa classes I see

protected transient PropertyChangeListener _persistence_listener;

[masc3d]

possibly this could be leveraged. but i suppose there’s no solution without getting hands dirty..