implicit declaration for database session playframework

Question

I'm working on a project with scala playframework and I implicitly declared the database connection session so that I can read/write to mysql database without having to call the database session every time. Is this a good practice?

Is there any trade off?

Thanks

Answer 1

Working with implicit sessions is certainly preferable so the framework can manage those details for you. The only real downside is needing (implicit s: Session) on all your methods, but this can be worked around .

There is also the added benefit of making things more "pluggable" during testing.

Answer 2

Passing "contextual" information around via implicits is a reasonable practice. You can even see this with the ExecutionContext passed to futures in the Scala standard library.

It's definitely better than global values or pseudo-global values in a singleton object, and it makes things easier to mock when testing.