Rocket: Schema validation

[ChrisBuchholz]

What would be the preferred way to plug in something like valico to validate JSON body data against a schema before it is serialized into a struct that is returned to its route?

Would it be better to validate the struct after it has been passed to the route by rocket?

[SergioBenitez]

This is the sort of thing FromData was tailor-made for. To integrate valico, I would:

1. Create a new type. Let's call it ValidJSON.

     struct ValidJSON<T: Deserialize>(T);
   

2. Implement FromData for ValidJSON, likely by calling contrib::JSON::from_data in the implementation, doing the validation, and returning an appropriate Outcome depending on the results.

You'd then use the type in a route as follows:

#[post("/", data = "<val>")]
fn (val: ValidJSON<T>) ...

[ChrisBuchholz]

Ah, exactly what I was looking for. Thanks!