Dominion

A Resource Centric framework to retrieve and receive update about any kind of resources (Network - DB - Anything Else)

Description

The primary goal of Dominion is to standardize the way an application handle its resources hiding the source or retrieval mechanism and make it fully type safe to avoid as most as possible programmer error. Ideally on the application layer a resource is a simple peace of information and something like location or storage should be merely considered as implementation detail. A Resource could be local or remote, could be transient or persisted, all of this should be mostrly ignored. The application layer should simply focus as much as possible on the business logic.

Note: At moment only Network resources are implemented

Being fully protocol oriented Dominion could be easily extended supporting different kind of Providers like DiskCache Provider, DB Provider, CoreData or Realm Provider and virtually anything else.

Core Concept

Resource

A Resource is the core concept of Dominion. It represent the access point for the requested peace of information. A Resource is a generic reference that wraps a specific type. Once initialized the Resource is fully opaque. As visible from the Resource interface, it's only possible to observe what is inside the resource, and future updates, and request a hard refresh if needed.

When you initialize a Resource a configuration object define it's behaviour while a provider is an object that use the configuration to proved the wrapped resource entity.

ResourceConfiguration

A ResourceConfiguration is a protocol that define how an entity, wrapped in a Resource can be retrieved. It works paired to a ResourceProvider able to fullfill the same type of Request. The ResourceConfiguration comes with two associated types:

Request define the type of request for the entity retrieval.
Downstream define the type of the entity wrapped by the Resource

ResourceProvider

A ResourceProvider is a protocol that simply allow an object retrieval. It has an associated type Request that is the type of request the provider is able to fullfill.

ResourceService

A ResourceService instance serve as resources tracker. It's responsability is to keep track of resources and make it available for future retrieval so that multiple application module can retrieve the same resource and see the underlaing entity if it's still valid.

Network Implementation

At this stage Dominion is able to retrieve a Codable remote resource out of the box. URLSession implements HTTPTransport that is passed as input in HTTPDataProvider initializer. URLSession could be replaced by Alamofire implementing the task function of the HTTPDataProvider on Alamofire.

HTTPDataProvider.Request is a standard URLRequest that will be used internally and passed to HTTPTransport to execute the request.

Basic Usage

Have your Codable object
Create the provider and Service, you will use them across your app
Create a configuration for a specific Response and retrieve the resource from the service.
Observe the Response.

// 1.
struct User: Codable {
    let name: String
}

// 2.
let provider = HTTPDataProvider(with: URLSession.shared)
let service = ResourceService(provider: provider)

// 3.
let configuration = URLRequestConfiguration<User, Error>(route: URL(string: "https://myresource.com/user")!)
let resource = service.getResource(for: configuration)

// 4.
resource.observe { result in
    switch result {
    case .success(let response):
        print(response)
    case .failure(let error):
        print(error)
    }
}