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iOS Build a Diary App Using Core Data Understanding Core Data Typical Core Data Stack

Posted by Nathaniel Rindlaub
Nathaniel Rindlaub
474 Points

Did you forget a line such as: static dispatch_once_t onceToken; in your defaultStack implementation?

When I attempt to implement the defaultStack method in my THCoreDataStack.m file as demonstrated:

  • (instancetype)defaultStack { static CBLCoreDataStack *defaultStack; dispatch_once(&onceToken, ^{ defaultStack = [[self alloc] init]; }); }

Xcode warns me "use of undeclared identifier onceToken". Should I instead declare the onceToken with a line such as:

static dispatch_once_t onceToken;

In the method implementation?

Thanks for the great tutorials btw!

Nathaniel Rindlaub
Nathaniel Rindlaub
474 Points

Correction: there's an inconsistency with my class prefixes. I am using CBL for all of them and forgot to change it to TH when I copied and pasted my code to make it consistent with Tree House's prefixes.