Override intent extras

Question

I'm creating notification using following code (Kotlin)

val builder = NotificationCompat.Builder(ctx)
           ........
      .setContentIntent(PendingIntent.getActivity(ctx, 891, ctx.newIntent<MainActivity>()
            .putExtra("id", member.id)
            .addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT), 0))

So when notification is tapped MainActivity will select user, from which notification arrived.

override fun onNewIntent(intent: Intent?) {
    val id = intent?.getStringExtra("id") ?: return
    selectUser(extra)
}

I'm sending 2 notifications from 2 different users. After click on first notification it works correct (id==_User1UUID) and selects user. Then I press back, send another notification from second user, tap on it and intent still contains previous user id and selects it (checked through breakpoint).

I know, it's because FLAG_ACTIVITY_REORDER_TO_FRONT, but I must keep only one instance of MainActivity.

Answer 1

The problem you are probably having is that you aren't generating unique PendingIntents. If you had 2 Notifications for different users, they would both be using the same PendingIntent and you would therefore see the same id extra in both.

To create unique PendingIntents, change this:

 .setContentIntent(PendingIntent.getActivity(ctx, 891, ctx.newIntent<MainActivity>()
        .putExtra("id", member.id)
        .addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT), 0))

to this:

int randomNumber = ... // Use some random number here, or use your "id" if your "id" can be converted to an integer here.
                       //  This random number needs to be unique for each Notification you create.

 .setContentIntent(PendingIntent.getActivity(ctx, randomNumber, ctx.newIntent<MainActivity>()
        .putExtra("id", member.id)
        .addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT), u))