Support for @propertyWrappers for CoreStoreObject properties #302

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adam · 2025-12-29T18:25:28+01:00

adam commented

2025-12-29 18:25:28 +01:00

Originally created by @JohnEstropia on GitHub (Jan 10, 2020).

Originally assigned to: @JohnEstropia on GitHub.

In a future update, these CoreStoreObject properties

Value.Required, Value.Optional
Transformable.Required, Transformable.Optional
Relationship.ToOne, Relationship.ToManyOrdered, Relationship.ToManyUnordered

will be deprecated in favor of these @propertyWrapper implementations:

Field.Stored (replacement for Value.Required andValue.Optional)
Field.Virtual (new, equivalent to transient versions of Value.Required andValue.Optional)
Field.Coded (replacement for Transformable.Required andTransformable.Optional, with additional support for custom encoders such as JSON)
Field.Identifier (new)
Field.Relationship (replacement for Relationship.ToOne, Relationship.ToManyOrdered, and Relationship.ToManyUnordered)

Field types that are marked above as "replacement"s will be able to migrate directly from their old counterparts. So if you have a property declared now as

let title = Value.Optional<String?>("title", initial: "Mr.")

you can directly convert it to

@Field.Stored("title")
var title: String? = "Mr."

when you are ready. They will be effectively equal to Core Data, and your VersionLocks will remain intact.

Note that this effectively forces you to use a different syntax for queries:

Before: From<Person>.where(\.title == "Mr.")
After: From<Person>.where(\.$title == "Mr.")

Also a couple of advantages:

The @propertyWrapper versions will be magnitudes performant and efficient than their current implementations. Currently Mirror reflection is used a lot to inject the NSManagedObject reference into the properties. With @propertyWrappers this will be synthesized by the compiler for us. (See https://github.com/apple/swift/pull/25884)
The @propertyWrapper versions, being structs, will give the compiler a lot more room for optimizations which were not possible before due to the need for mutable classes.

The only disadvantage will be

You need to update your code by hand to migrate to the new @propertyWrappers
(But the legacy ones will remain available for quite a while, so while it is recommended to migrate soon, no need to panic)

Post implementation ideas:

Blob support (background fetched)
Compound keys
Traits (ReadOnly, etc.)

Originally created by @JohnEstropia on GitHub (Jan 10, 2020). Originally assigned to: @JohnEstropia on GitHub. In a future update, these `CoreStoreObject` properties - `Value.Required`, `Value.Optional` - `Transformable.Required`, `Transformable.Optional` - `Relationship.ToOne`, `Relationship.ToManyOrdered`, `Relationship.ToManyUnordered` will be deprecated in favor of these `@propertyWrapper` implementations: - `Field.Stored` (replacement for `Value.Required` and`Value.Optional`) - `Field.Virtual` (new, equivalent to `transient` versions of `Value.Required` and`Value.Optional`) - `Field.Coded` (replacement for `Transformable.Required` and`Transformable.Optional`, with additional support for custom encoders such as JSON) - `Field.Identifier` (new) - `Field.Relationship` (replacement for `Relationship.ToOne`, `Relationship.ToManyOrdered`, and `Relationship.ToManyUnordered`) `Field` types that are marked above as "replacement"s will be able to migrate directly from their old counterparts. So if you have a property declared now as ```swift let title = Value.Optional<String?>("title", initial: "Mr.") ``` you can directly convert it to ```swift @Field.Stored("title") var title: String? = "Mr." ``` when you are ready. They will be effectively equal to Core Data, and your `VersionLock`s will remain intact. Note that this effectively forces you to use a different syntax for queries: - Before: `From<Person>.where(\.title == "Mr.")` - After: `From<Person>.where(\.$title == "Mr.")` Also a couple of advantages: - The `@propertyWrapper` versions will be magnitudes performant and efficient than their current implementations. Currently `Mirror` reflection is used a lot to inject the `NSManagedObject` reference into the properties. With `@propertyWrapper`s this will be synthesized by the compiler for us. (See https://github.com/apple/swift/pull/25884) - The `@propertyWrapper` versions, being `struct`s, will give the compiler a lot more room for optimizations which were not possible before due to the need for mutable classes. The only disadvantage will be - You need to update your code by hand to migrate to the new `@propertyWrapper`s (But the legacy ones will remain available for quite a while, so while it is recommended to migrate soon, no need to panic) Post implementation ideas: - Blob support (background fetched) - Compound keys - Traits (ReadOnly, etc.)

adam added the enhancement fixed labels 2025-12-29 18:25:28 +01:00

adam closed this issue

2025-12-29 18:25:28 +01:00

adam commented

2025-12-29 18:25:29 +01:00

@JohnEstropia commented on GitHub (Mar 27, 2020):

Released now for version 7.1.0!
Please check the release notes: https://github.com/JohnEstropia/CoreStore/releases/tag/7.1.0

@JohnEstropia commented on GitHub (Mar 27, 2020): Released now for version `7.1.0`! Please check the release notes: https://github.com/JohnEstropia/CoreStore/releases/tag/7.1.0

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Reference: starred/CoreStore-JohnEstropia#302