osinka / play-toggles   2.0.0

• Martin Fowler: Feature Toggles
• Martin Fowler: FeatureToggle
• Java: Feature Flags, Toggles, Controls

• Very short & simple
• Compatible with its PHP counterpart: php-toggles

• Calculates strategies only once per browser session and then caches the result in a session cookie
• Gradual rollout strategy does not depend on user ID per se. Instead, it may be given any user-related textual ID.
• Whitelist and Blacklist depend on the same user ID.
• Provides AnonymousOn (enables a feature for anonymous users) and AnonymousOff (disables a feature for anonymous users)

Init:

import com.osinka.play.toggles._

object Toggles extends ToggleRegistry {
  private val authReqPf: PartialFunction[RequestHeader,String] = {
    case ar: AuthenticatedRequest[_, _] => ar.user.toString
  }

  private object UserStrategies extends UserStrategies(authReqPf.lift)

  val socialBlock = toggle("socialBlock")(
    Strategies.internalNet,
    UserStrategies.anonymousOff,
    UserStrategies.whitelist
  )
  val testedAndOn = toggle("testedAndOn")(
    Strategies.internalNet,
    UserStrategies.anonymousOff,
  )
  val inDevelopment = toggle("inDevelopment")(
    Strategies.internalNet,
    UserStrategies.anonymousOff,
  )
}

You would need to bind ToggleRegistry to Toggles implementation:

class Module extends AbstractModule {
  def configure(): Unit = {
    bind(classOf[ToggleRegistry]).to(Toggles)
  }
}

In conf/application.conf:

toggles {
  socialBlock {
    whitelist = ["123456", "98765"]
  }
  testedAndOn.enabled = true
  inDevelopment.enabled = false
}

Strategies will be calculated only if enabled is not defined in the configuration. The order of checks is as follows:

1. if the feature is enabled in the configuration, it is active
2. if the feature is in a session cookie, it is active
3. if the feature is disabled in the configuration, it is active
4. then the strategies get checked one by one. The first that gives a definite result wins.

In order to check the toggles, either a filter should be used:

object Filter @Inject() (toggles: ToggleFilter) extends DefaultHttpFilters(toggles)

or wrap specific actions into ToggleAction(Toggles)

Then check the toggle anywhere (depends on implicit requestHeader):

if (Toggles.socialBlock.active) {
}