Kuery 0.3.0

Kuery 0.3.0

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TestsTested ✓
LangLanguage SwiftSwift
License MIT
ReleasedLast Release Sep 2017
SwiftSwift Version 4.0
SPMSupports SPM ✓

Maintained by kishikawa katsumi.

Kuery 0.3.0

Kuery

Kuery, a type-safe Core Data query API using Swift 4's Smart KeyPaths. Inspired and borrowed a lot of things from QueryKit and RealmEx.

Requirements

Kuery is written in Swift 4.

Description

Kuery provides type safety, code completion and avoidance of typos against NSPredicate queries.

Before

NSPredicate(format: "name == %@", "Katsumi")
NSPredicate(format: "age > %@", 20)

After

Query(Person.self).filter(\Person.name == "Katsumi")
Query(Person.self).filter(\Person.age > 20)

The following code should be a compile error.

Query(Person.self).filter(\Person.name > 20) // Compile error
Query(Person.self).filter(\Dog.name == "John") // Compile error

Usage

context.perform {
    let results = try Query(Person.self)
        .filter(\Person.name == "Katsumi")
        .execute()
}
context.perform {
    let results = try Query(Person.self)
        .filter(\Person.age == 36)
        .execute()
}
context.perform {
    let results = try Query(Person.self)
        .filter(\Person.age > 20)
        .execute()
}
context.perform {
    let results = try Query(Person.self)
        .filter(\Person.name == "Katsumi")
        .filter(\Person.age == 36)
        .execute()
}
context.perform {
    let results = try Query(Dog.self)
        .filter(\Dog.owner == person)
        .execute()
}

Feature request for Swift Standard Library

It requires a string representation of KeyPath to construct NSPredicate from KeyPath. However, the API is not officially visible currently. The feature request is tracked at SR-5220.

[SR-5220] Expose API to retrieve string representation of KeyPath - Swift