ToOwned

[cunning flint]

Hi guys. I have some doubts about how to transform a list of structures into another list of structures with different types. My use case is the following, I have a structure that is the data model that is saved in my database, however the data model that I return in the interface is more abstract and therefore I need to transform the list of structures in the database to a return structure list.

Example of how I'm doing it, but I'm not sure if it's expensive to do this or if there's a better way.

Added Clone annotation to use .to_owned() on User

And I'm not sure if this practice is good

And I'm not sure if the .to owned() clones the entire structure and keeps the old one or clones only the reference

[neon seal]

What about

let mut results: Vec<UserResponse> = Vec::new();
while cursor.advance().await.ok().unwrap() {
  let user = cursor.deserialize_current().ok().unwrap();
  let result = build_response(user);
  results.push(result);
}
HttpResponse::Ok().json(results)
```You aren't using `users` after so idk why you'd need to clone it. `to_owned` does clone the entire structure. You can't move something when all you have is a reference.

[cunning flint]

Hi, thanks for the reply. The User is my database model, it has data in it that I don't want to return in the request and that's why I created this build_response function that will create the UserResponse with the data that should be returned.

Example is the password in User, I can't return it, so I need to create a return structure.

@neon seal So, do you think this way I did is a good practice? Or is there another better way?

[neon seal]

That's fine. I just removed the clone and the intermediate vec since they're unnecessary.

[cunning flint]

@neon seal Could you send me an example, please?

[neon seal]

I did

[cunning flint]

Oh yes. This right?

In this case you sent, the business rule is "mixed" with the database query rule. I wanted to isolate these queries rules in a module to be able to reuse them, so I didn't do them inside the same while. Could you send me an example in the same context that I sent but using good practices?

@neon seal In this case you sent, the business rule is "mixed" with the database query rule. I wanted to isolate these queries rules in a module to be able to reuse them, so I didn't do them inside the same while. Could you send me an example in the same context that I sent but using good practices?