What are the advantages of using Catalogs? My goal is to have only 3 power-ups in my game, so it seems easier to me to only save their count. I also want my players to be able to use power-ups offline (and I would like to allow them to buy power-ups offline). I want to use Virtual Currency for the purchases (and also for reviving the player, so I probably need to update it from the client when it reconnects). Thanks in advance.
Catalogs are what give you the ability to use the economy/inventory system in PlayFab. Simply put, you define in a catalog the items that you want to be able to grant or sell to players. You can define prices for them in any virtual currency you have defined for your game, or for "RM" (real money - USD pennies, though we also handle foreign currency pricing, if needed). If your game is on a platform like iOS or Android, where you're required to use their service for purchasing, you would use the relevant receipt validation API call, which does a series of checks to ensure the validity of the receipt (and that it hasn't already been used), then grants the correct item from the catalog to the player inventory.
As a Web API based service, we do not provide offline functionality, and I do have to caution that there is no effective way to fully secure anything you allow the client to be authoritative concerning (by definition, all offline actions are client-authoritative). So while you can provide the player with a way to continue to make purchases offline, and then sync with us by using Cloud Script to modify the currency balances and inventory, that approach is highly vulnerable to cheating.
