What is the right way to handle user session?

[wilburx9]

We run an experiment before the user log in and after they log in. We initialize the client like so:

val config = ExperimentConfig.builder()
      .build()
val experiment = Experiment.initializeWithAmplitudeAnalytics(app, $API_KEY  config,)
val user = ExperimentUser.builder()
      .userId(userAuth0Id)
      .deviceId(deviceIdFromAnalytics)
      .build()
experiment?.start(user)?.get()

Before the user logs in, userAuth0Id is null and calling experiment?.variant(variantKey) returns the expected variant.

After logging in, we call the code above with a valid userAuth0Id. But the now logged-in user doesn't get the expected variant of the experiment that is assigned to their userId, the properties in the object returned in experiment?.variant(variantKey) are just null. I have tried calling experiment?.clear() after login but that doesn't fix it.

However, if you restart the app, they get the right values.

What is the right way to handle this?

I am using v1.11.0

[tyiuhc]

Hi @wilburx9, many thanks for reaching out. In your implementation, after the user logs in, do you re-initialize the client as well, or just call experiment?.variant(variantKey) again? If it's the latter, you should use setUser() on the new user object (with valid userAuth0Id) before calling variant(). Let us know if this helps with your issue.

[wilburx9]

After the user logs in, I call:

val config = ExperimentConfig.builder()
      .build()
val experiment = Experiment.initializeWithAmplitudeAnalytics(app, $API_KEY  config,)
val user = ExperimentUser.builder()
      .userId(userAuth0Id)
      .deviceId(deviceIdFromAnalytics)
      .build()
experiment?.start(user)?.get()

And userAuth0Id is a valid non-null and non-empty string at this point.

[tyiuhc]

This issue has been addressed in v1.11.1. Additionally, if you have initialized the client before the user logged in, you can also just do:

val user = ExperimentUser.builder()
      .userId(userAuth0Id)
      .deviceId(deviceIdFromAnalytics)
      .build()
experiment.setUser(user)

to set the user to be a new user with valid userAuth0Id.