PredicateFlow - SwiftGit

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PredicateFlow

March 28, 2024

Write amazing, strong-typed and easy-to-read NSPredicate. This library allows you to write flowable NSPredicate, without guessing attribution names, predicate operation or writing wrong arguments type.

Supported platforms

iOS 9.0+
macOS 10.9+
tvOS 9.0+
watchOS 2.0+

Installation

CocoaPods is actually the only way to install it.

Cocoapods

CocoaPods 0.39.0+ is required to build this library

Add pod 'PredicateFlow' to your Podfile and run pod install
In Xcode, click on your project in the file list, choose your target under TARGETS, click the Build Phases tab and add a New Run Script Phase by clicking the plus icon in the top left
Drag the new Run Script phase above the Compile Sources phase and below Check Pods Manifest.lock, expand it and paste the following script:


                                              
                                                “$PODS_ROOT/Sourcery/bin/sourcery” –sources “$PODS_ROOT/PredicateFlow/PredicateFlow/Classes/Utils/” –sources “$SRCROOT” –templates “$PODS_ROOT/PredicateFlow/PredicateFlow/Templates/PredicateFlow.stencil” –output “$SRCROOT/PredicateFlow.generated.swift”

In case you are using PredicateFlow-Realm, past the following script instead of the above one:


                                              
                                                “$PODS_ROOT/Sourcery/bin/sourcery” –sources “$PODS_ROOT/PredicateFlow/PredicateFlow/Classes/Utils/” –sources “$SRCROOT” –sources “$PODS_ROOT/RealmSwift” –templates “$PODS_ROOT/PredicateFlow/PredicateFlow/Templates/PredicateFlow-Realm.stencil” –output “$SRCROOT/PredicateFlow.generated.swift”

For Xcode 10 only, add a new Output Files and paste the following:


                                              
                                                $SRCROOT/PredicateFlow.generated.swift

Build your project. In Finder you will now see a PredicateFlow.generated.swift in the $SRCROOT-folder, drag the PredicateFlow.generated.swift files into your project and uncheck Copy items if needed

Tip: Add the *.generated.swift pattern to your .gitignore file to prevent unnecessary conflicts.

Usage

Define a class/struct with its own attributes, which implements PredicateSchema:


                                              
                                                import PredicateFlow

class Dog: PredicateSchema {

private var name: String = “”
private var age: Int = 0
private var isHungry: Bool = false
private var owner: Person?
}

class Person: PredicateSchema {

enum Sex {
case male
case female
}

private var name: String = “”
private var birth: Date?
private var sex: Sex!
private var dogs: [Dog] = []
}

Build the project. PredicateFlow will autogenerate attributes references to build predicates, putting them in structures.


                                              
                                                // Generated using Sourcery 0.10.0 — https://github.com/krzysztofzablocki/Sourcery

// DO NOT EDIT
import PredicateFlow
/// The “Dog” Predicate Schema

internal struct DogSchema: GeneratedPredicateSchema {

private var compoundFieldBuilder: CompoundFieldBuilder
/// DO NOT USE THIS INIT DIRECTLY!

internal init(compoundFieldBuilder: CompoundFieldBuilder) {

self.compoundFieldBuilder = compoundFieldBuilder

}
/// “name” property

internal var name: StringPredicateProperty { return builder.string(“name”) }

/// “name” property for static access

internal static var name: StringPredicateProperty { return DogSchema().name }
// Other properties of Dog class autogenerated…

}

/// The “Person” Predicate Schema

internal struct PersonSchema: GeneratedPredicateSchema {

private var compoundFieldBuilder: CompoundFieldBuilder
/// DO NOT USE THIS INIT DIRECTLY!

internal init(compoundFieldBuilder: CompoundFieldBuilder) {

self.compoundFieldBuilder = compoundFieldBuilder

}
/// “name” property

internal var name: StringPredicateProperty { return builder.string(“name”) }

/// “name” property for static access

internal static var name: StringPredicateProperty { return PersonSchema().name }
// Other properties of Person class autogenerated…

}

To type a floawable NSPredicate, just write:


                                              
                                                DogSchema.age.isEqual(10).query()

// or

// Vanilla mode:

// NSPredicate(“age == %@”, 10)

You can also write compound predicate, and use deeper fields:


                                              
                                                PredicateBuilder(DogSchema.age > 10)

.and(DogSchema.isHungry.isTrue)

.and(DogSchema.age.between(1, 10))

.and(DogSchema.owner.element().name == “Foo”)

.or(DogSchema.owner.element().dogs.maxElements().age > 10)

.or(DogSchema.owner.element().dogs.anyElements().name == “Foo”)

.build()
// Vanilla mode:

// NSPredicate(“age > %@ AND isHungry == %@ AND age BETWEEN %@ AND owner.name == %@ OR owner.dogs.@max.age > %@ OR ANY owner.dogs.name == %@”, 10, true, [1, 10], “Foo”, 10, “Foo”)

PredicateFlow can also build KeyPaths, and you can use it to get a strong-typed one.


                                              
                                                DogSchema.age.keyPath()

DogSchema.owner.element().dogs.keyPath()
// Vanilla mode:

// “age”

// “owner.dogs”

PredicateFlow/Realm

If you want to use flowable and strong-typed queries in Realm, add both pod 'PredicateFlow' and pod 'PredicateFlow/Realm' to your Podfile and run pod install.


                                              
                                                let realm = try! Realm()

realm.objects(Dog.self)

.filter(DogSchema.age.isGreater(than: 10))

.filter(DogSchema.isHungry.isTrue)

.sorted(DogSchema.age.ascending())
// Vanilla mode:

realm.objects(Dog.self)

.filter(“age > %@”, 10)

.filter(“isHungry == %@”, true)

.sorted(“age”, ascending: true)

GitHub

View Github

#cocoapods #coredata #flow #ios #library #macos #pods #realmswift #swift #tvos #watchos