Issue about appStoreReceiptURL - ios

Question

I am trying to convert my paid app to free version with IAP , so basically I need to check if users bought previous version then unlock IAP item , I am not sure I am doing right here or not ! even is it possible to check and track 'appStoreReceiptURL' in development process ? here is my code :
NSURL* url = [[NSBundle mainBundle] appStoreReceiptURL];
NSLog(#"receiptUrl %#",[url path]);
NSError* err = nil;
if (![url checkResourceIsReachableAndReturnError:&err]){
SKReceiptRefreshRequest* request = [[SKReceiptRefreshRequest alloc] initWithReceiptProperties:nil];
request.delegate = self;
[request start];
}
-(void)requestDidFinish:(SKRequest*)request{
if([request isKindOfClass:[SKReceiptRefreshRequest class]]){
NSLog(#"YES, You purchased this app");
}
}
-(void)request:(SKRequest*)request didFailWithError:(NSError *)error{
NSLog(#"NO, you need to buy it ");
}
Now I am able to login with my Apple ID,and after I signed in it tells me YES, You purchased this app", and yes I really bought my app ! , I am going to make sure everything is alright .
Does this process should happen in every update ?

Answer 1

Here is a simple solution
#import <StoreKit/StoreKit.h>
Don't forget to add its delegates
<SKPaymentTransactionObserver, SKProductsRequestDelegate>
Payment Validation
- (IBAction)boughtIt:(id)sender {
NSURL* url = [[NSBundle mainBundle] appStoreReceiptURL];
NSLog(#"receiptUrl %#",[url path]);
NSError* err = nil;
if (![url checkResourceIsReachableAndReturnError:&err]){
SKReceiptRefreshRequest* request = [[SKReceiptRefreshRequest alloc] initWithReceiptProperties:nil];
request.delegate = self;
[request start];
_activity.hidden = NO;
}
}
-(void)requestDidFinish:(SKRequest*)request{
if([request isKindOfClass:[SKReceiptRefreshRequest class]]){
NSLog(#"YES, You purchased this app");
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Congrats !" message:#"Welcome To The World Of Dinosaurs" delegate:self
cancelButtonTitle:#"Cancel" otherButtonTitles:nil, nil];
[alert show];
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:#"isPurchased"];
[[NSUserDefaults standardUserDefaults] synchronize];
_activity.hidden = YES;
[self dismissViewControllerAnimated:YES completion:nil];
}
}
- (void)request:(SKRequest*)request didFailWithError:(NSError *)error{
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Sorry !" message:#"It seems you did not purchase this app before, if you like to unlock all content and features please purchase Paleontologist Pack" delegate:self
cancelButtonTitle:#"Cancel" otherButtonTitles:nil, nil];
[alert show];
_activity.hidden = YES;
// [self dismissViewControllerAnimated:YES completion:nil];
NSLog(#"NO, you need to buy it ");
}
This works only if a user PURCHASED the application , it doesn't work for redeem codes