PredicateFlow

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

  1. Add pod 'PredicateFlow' to your Podfile and run pod install

  2. 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

  3. 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

  4. 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 [email protected] > %@ 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)

Contributing

PredicateFlow is an open source project, so feel free to contribute.
You can open an issue for problems or suggestions, and you can propose your own fixes by opening a pull request with the changes.

License

PredicateFlow is available under the MIT license. See the LICENSE file for more info.

Attributions

This library is powered by Sourcery.

Author

Andrea Del Fante, [email protected]

GitHub

https://github.com/andreadelfante/PredicateFlow