CoreStore v7.2.0 Release Notes

Release Date: 2020-06-20 // 7 months ago
  • 0️⃣ Default values vs. Initial values

    ⏪ One common mistake when assigning default values to CoreStoreObject properties is to assign it a value and expect it to be evaluated whenever an object is created:

    // ❌class Person: CoreStoreObject { @Field.Stored("identifier") var identifier: UUID = UUID() // [email protected]("createdDate") var createdDate: Date = Date() // Wrong!}
    

    0️⃣ This default value will be evaluated only when the DataStack sets up the schema, and all instances will end up having the same values. This syntax for "default values" are usually used only for actual reasonable constant values, or sentinel values such as "" or 0.

    👍 For actual "initial values", @Field.Stored and @Field.Coded now supports dynamic evaluation during object creation via the dynamicInitialValue: argument:

    // ✅class Person: CoreStoreObject { @Field.Stored("identifier", dynamicInitialValue: { UUID() }) var identifier: UUID @Field.Stored("createdDate", dynamicInitialValue: { Date() }) var createdDate: Date }
    

    0️⃣ When using this feature, a "default value" should not be assigned (i.e. no = expression).