NetworkKit is a networking library written in Swift. It offers the following:
- Idiomatic Swift types for representing HTTP requests and related data types.
- A type-safe Retrofit inspired DSL for declaring HTTP interfaces.
- Utilities to manipulate standard certificate formats used in secure telecommunication (ASN.1, PKCS 7, X509)
- Common implementations for custom framing protocols.
- Extensions for the
NetworkExtensionframework.
NetworkKit allows for powerful declarative composition of various kinds of HTTP interfaces.
A NetworkKit HTTP interface is fundamentally composed of the following:
- A base URL.
- A list of endpoints.
- A generic
Endpointclass (inheriting fromBaseHTTPEndpoint) responsible for configuring a generic HTTP request containing shared parameters (such as API keys etc.).
Specific API endpoints by initializing the generic Endpoint class declared in the interface, and annotating them with NetworkKit provided decorators (i.e. property wrappers). The following decorators are supported:
@Host(...)@Path(...)@AbsolutePath(...)@DELETE@GET@PATCH@POST@PUT@Query(...)@Header(...)@Body(...)
These decorators can be composed together to declare the configuration for an API endpoint.
Here is a sample NetworkKit interface for the GIPHY API:
public struct GIPHY_API: RESTAPISpecification {
public var apiKey: String
public var host = URL(string: "https://api.giphy.com")!
public init(apiKey: String) {
self.apiKey = apiKey
}
public var baseURL: URL {
host.appendingPathComponent("/v1")
}
public var id: some Hashable {
apiKey
}
@Path("gifs/search")
@GET
@Query({ context in
return [
"api_key": context.root.apiKey,
"q": context.input.q,
"limit": context.input.limit?.description
]
})
var search = Endpoint<RequestBodies.Search, ResponseBodies.Search, Void> ()
}
extension GIPHY_API {
public final class Endpoint<Input, Output, Options>: BaseHTTPEndpoint<GIPHY_API, Input, Output, Options> {
override public func buildRequestBase(
from input: Input,
context: BuildRequestContext
) throws -> Request {
let request = try super.buildRequestBase(from: input, context: context)
.header(.accept(.json))
.header(.contentType(.json))
return request
}
override public func decodeOutputBase(
from response: Request.Response,
context: DecodeOutputContext
) throws -> Output {
try response.validate()
return try response.decode(Output.self, using: JSONDecoder(keyDecodingStrategy: .convertFromSnakeCase))
}
}
}
extension GIPHY_API {
public enum RequestBodies {
public struct Search: Codable, Hashable {
public var q: String
public var limit: Int32?
public var offset: Int?
public var lang = "en"
}
}
public enum ResponseBodies {
public struct Search: Codable, Hashable {
public struct Pagination: Codable, Hashable {
public let offset: Int32
public let totalCount: Int32
public let count: Int32
}
public struct Meta: Codable, Hashable {
public let msg: String
public let status: HTTPResponseStatusCode
public let responseId: String
}
public let data: [GIPHY_API.Schema.GIFObject]
public let pagination: Pagination
public let meta: Meta
}
}
}
extension GIPHY_API {
public enum Schema {
public struct GIFObject: Codable, Hashable {
public struct Images: Codable, Hashable {
public struct Downsized: Codable, Hashable {
public let url: URL
public let width: String
public let height: String
public let size: String
}
public let downsized: Downsized
}
public let type: String
public let id: String
public let slug: String
public let url: URL
public let bitlyUrl: URL?
public let embedUrl: URL?
public let username: String?
public let source: String
public let rating: String?
// ...
public let images: Images
public let title: String
}
}
}