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Video Tutorial: Intermediate Core Data Part 3: Mapping Models

Learn how to create your own mapping model which Core Data will use to perform the migration from an older version of your data model to the latest version.

This is a companion discussion topic for the original entry at https://www.raywenderlich.com/3815-intermediate-core-data/lessons/4


First of all, great video Greg, I’m learning quite a bit from your various series.

I’m quite a newbie to swift programming and I just finished watching part 3 of the intermediate core data video but I hit a snag migrating the source data; all the data on the app is nil. I downloaded the finished demo thinking that perhaps it was due to a typo somewhere but the results from building said project were exactly the same. Clearly I am missing something but what exactly that something would be is sending me in circles on google. Please help!


You need to run the app once before you make the code changes. Try unzipping the project again and running the starter code.

Thanks for the response!

Prior to my post I actually started after I reseted the data on the emulator without any changes to the code. But after I resolved the warnings, the code seemed to work. It seemed odd at the time but at least I’m no longer blocked!

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Greg, is there a solution to the Über-haxx0r challenge? I see that the next lesson’s starter code doesn’t implement the UIPickerView as DeviceType