CODEWITHSUNDEEP
swiftdatehealthkitswift3
Gerd Castan
Gerd Castan

Reputation: 6849

create DateComponents / NSDateComponents from String and vice versa

Is there an (elegant or preferred) way to convert a DateComponents object to a String and back so that

DateComponents -> String -> DateComponents

is alway possible and the resulting object equals the original object? (not identical) (like CustomStringRepresentable)

For NSDate / Date there is an NSDateFormatter / DateFormatter that is able to do this trick, converting back and forth.

For DateComponents there is a DateComponentsFormatter, but it appears to me not to support the direction from String to DateComponents.

motivation for this question

HealthKit used to store birthdays as NSDate up to iOS 9.x.

Starting with iOS 10, HealthKit uses DateComponents as a model for birthdays. (And deprecated NSDate for birthdays)

I'm trying to reflect HealthKits model change in my own data model of a HealthKit centric app. The most straight forward is to use DateComponents in my model as HealthKit does.

As I need to save my model to a file and load it again, the answer to this question would enable me to do this.

The obvious fallback is to convert DateComponents to Date and save that. But there must be a good reason why Apple deprecated Date for birthdays.

Upvotes: 0

Views: 472

Answers (1)

vadian
vadian

Reputation: 285082

Just save the date components directly via NSKeyedArchiver since NSDateComponents conforms to NS(Secure)Coding.

Upvotes: 1

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