iOS in-app purchase subscription get free trial period length from SKProduct

Question

I am working on in-app purchases with subscriptions. In swift, you can get price and price locale from the SKProduct like so:

weeklyProduct.price.doubleValue   weeklyProduct.priceLocale.currencySymbol 

where weeklyProduct is a SKProduct.

Is it possible to get the free trial length? For example, I specified a two week free trial for the product. can I get this from the SKProduct?

Answer 1

I've solved it using DateComponentsFormatter, that saves you a lot of time localizing in different languages and handling plurals and whatnot. This might seem like a lot of code, but I hope it will save me time in the future.

import Foundation  class PeriodFormatter {     static var componentFormatter: DateComponentsFormatter {         let formatter = DateComponentsFormatter()         formatter.maximumUnitCount = 1         formatter.unitsStyle = .full         formatter.zeroFormattingBehavior = .dropAll         return formatter     }      static func format(unit: NSCalendar.Unit, numberOfUnits: Int) -> String? {         var dateComponents = DateComponents()         dateComponents.calendar = Calendar.current         componentFormatter.allowedUnits = [unit]         switch unit {         case .day:             dateComponents.setValue(numberOfUnits, for: .day)         case .weekOfMonth:             dateComponents.setValue(numberOfUnits, for: .weekOfMonth)         case .month:             dateComponents.setValue(numberOfUnits, for: .month)         case .year:             dateComponents.setValue(numberOfUnits, for: .year)         default:             return nil         }          return componentFormatter.string(from: dateComponents)     } } 

It requires to convert the SKProduct period unit into a NSCalendarUnit

import StoreKit  @available(iOS 11.2, *) extension SKProduct.PeriodUnit {     func toCalendarUnit() -> NSCalendar.Unit {         switch self {         case .day:             return .day         case .month:             return .month         case .week:             return .weekOfMonth         case .year:             return .year         @unknown default:             debugPrint("Unknown period unit")         }         return .day     } } 

And you can call it from a SubscriptionPeriod like this:

import StoreKit  @available(iOS 11.2, *) extension SKProductSubscriptionPeriod {     func localizedPeriod() -> String? {         return PeriodFormatter.format(unit: unit.toCalendarUnit(), numberOfUnits: numberOfUnits)     } } 

Which you can in turn call from a SKProductDiscount like so. Please note I didn't implement the other PaymentModes for now.

import StoreKit  @available(iOS 11.2, *) extension SKProductDiscount {     func localizedDiscount() -> String? {         switch paymentMode {         case PaymentMode.freeTrial:             return "Free trial for \(subscriptionPeriod.localizedPeriod() ?? "a period")"         default:             return nil         }     } } 

Answer 2

You can get it, but as mentioned above it works only starting from iOS 11.2, for other versions you'll have to get it from your server via API.

Here is an example code that I've used:

if #available(iOS 11.2, *) {   if let period = prod.introductoryPrice?.subscriptionPeriod {      print("Start your \(period.numberOfUnits) \(unitName(unitRawValue: period.unit.rawValue)) free trial")   } } else {   // Fallback on earlier versions   // Get it from your server via API }  func unitName(unitRawValue:UInt) -> String {     switch unitRawValue {     case 0: return "days"     case 1: return "weeks"     case 2: return "months"     case 3: return "years"     default: return ""     } }