InjectPropertyWrapper

Provides a generic Swift @Inject property wrapper that can be used to inject objects / services from a dependency injection framework of your choice.

Basic Usage

First, you need to implement the Resolver protocol for the Dependency Injection (DI) framework you are using.

For example, when using Swinject:

extensionContainer:InjectPropertyWrapper.Resolver{}

In case of Swinject the Container class already contains a method with the same signature (resolve<T>(_ type: T, name: String?)) as the InjectPropertyWrapper Resolver protocol requires.

Then you need to set the global resolver (for example in your app delegate):

letcontainer=Container()InjectSettings.resolver = container

Register some objects in the container:

container.register(APIClient.self){ _ inAPIClient()}
container.register(MovieRepository.self){ _ inIMDBMovieRepository()}
container.register(MovieRepository.self, name:"netherlands"){ _ inIMDBMovieRepository("nl")}

Now you can use the @Inject property wrapper to inject objects/services in your own classes:

classIMDBMovieRepository:MovieRepository{@InjectprivatevarapiClient:APIClient...func fetchTop10(completionHandler:@escaping(movies:[Movie])->Void){...}}classMovieViewModel:BindableObject{publicvardidChange=PassthroughSubject<Void,Never>()publicprivate(set)vartop10:[Movie]?{
didSet {
didChange.send()}}@InjectprivatevarmovieRepository:MovieRepositoryfunc load(){
movieRepository.fetchTop10(){[weak self] movies inself?.top10 = movies
}}}

It is also possible to inject different objects of the same type using the name parameter:

classMovieViewModel:BindableObject{...@InjectprivatevarglobalMovieRepository:MovieRepository@Inject(name:"netherlands")privatevarnlMovieRepository:MovieRepository...}

Normally if the property wrapper is unable to resolve a dependency it will raise a non-recoverable fatal error. If for some reason you expect an object sometimes to be unavailable in your container, you can mark the property as optional:

classMovieViewModel:BindableObject{...@Inject(name:"germany")privatevardeMovieRepository:MovieRepository?...}

Testing

To run the tests for this package make sure the ENABLE_TESTS environment variable is set to 1 or true. For example when using the command line:

ENABLE_TESTS=1 swift test

This allows the package to only load certain dependencies when testing.

License

This project is licensed under the terms of the MIT license. See the LICENSE file.