在iOS中管理SKProductsRequest的最佳方法是什么？

Question

I'm working on an app that offers in-app purchases of non-consumable items.

The non-consumables are built into the app, as opposed to being downloaded from a server, so actually we're just granting access to the content.

Our app:

• shows a Netflix style library of content - some is free and some is purchasable.
• must work without an internet connection (although one is required for purchases, obvs.)
• should show the purchasable content within the library, even when there is no Internet connection

Questions:

When is the best time to call start on the SKProductsRequest to fetch the product into etc. from iTunes Connect? In application:didFinishLaunchingWithOptions: ? Or in my controller when it's loaded?

• We want to show the product price on screen, but also avoid a situation where the product prices have changed, and the User's app has not updated the price on screen.

How frequently should I update the product info? Whenever the screen loads? Whenever it appears? When the app is started?

Answer 1

A good solution would be to implement Push Notifications and whenever you change the prices, broadcast a push notification to the app, Which would fetch new prices!

Update: If internet is not available at that time, then you can invalidate current prices so that when app is launched again it updates the prices! You can store a BOOL in NSUserDefaults which tells if the prices are up to date or not.

Answer 2

I came up with my own solution to this problem using NSNotificationCenter.

Basically, my process is this:

• When the app starts, tell my custom ProductList class to update the list of products.
• When the app's internet connection state changes (to has connection), tell the ProductList class to update the list of products.
• The ProductList method update_all will only perform the iTunesConnect request if:
  • The array of SKProducts I'm storing is empty (we don't already have the product info)
  • OR The list of products hasn't been updated in a day or longer (the info may be stale)

Since I wanted to handle a situation where a user started the device without internet connection, and loaded the purchasable content before connecting, I set up an observer.

Once the Products have been retrieved from iTunes connect, I send out an NSNotification to any views that may be observing, so they can update the prices etc.

Hope that makes sense and helps somebody?

Answer 3

If you want to show prices for your In App Purchase dynamically then I think you should not call the methods in application didFinishLaunchingWithOptions.

As it is going to get called every time only when your app launches. If your app is running and you change the price tier of the app at that time then the user will not be able to see that change at that time. User will have to launch the app again.

So you should call it from your viewcontroller's ViewWillAppear method. Thats what I did for one of my projects.

So if you change the price tier from itunes whenever, then even if your app is running then whenever user comes to that view, changes will be seen.

Hope it helps you.