When writing networking layers, it´s common to end with a lot of boilerplate or repeated code.
There are currently some libraries that one can use in order to improve code readability and to avoid writing boilerplate, but they are usually so bloated that one doesn´t use the half of what that library offers.
On the other hand, there are some other libraries that are lightweight, but they often fall short when you need more advanced functionality.
Conn is the library that resolves this issue. It is very lightweight (118 lines counting empty lines until now), but it is still highly modular while it doesn't require the developer to write any boilerplate.
You can read more about the reasoning behind this library in my article in Medium.
- Declarative style
- Very lightweight
- Parses JSON to models
- Replaceable network dispatcher
- Minimal boilerplate required
The first thing you have to do is describing your requests as structs, classes or enums conforming to the RequestType protocol. For instance:
struct GetAllUsers: RequestType {
typealias ResponseType = [User]
var data: RequestData {
return RequestData(path: "https://jsonplaceholder.typicode.com/users")
}
}ResponseType is an associatedtype that declares the format of the response. In this case, we expect to have an array of User as a response. The type associated to the request must implement Codable in order to be parsed. Take User as an example:
struct User: Codable {
let id: Int
let username: String
}RequestData is a plain struct that defines the format of the request. In this case we are only defining a path (url), but RequestData also supports defining a http method, headers and params (body).
This is all you have to do. Then, to execute the request, RequestType has a method called execute() that actually dispatches the request:
GetAllUsers().execute(
onSuccess: { (users: [User]) in
// Do something with users
},
onError: { (error: Error) in
// Do something with error
}
)Please note that users are already parsed as an array of User.
If you need to do something more complex, use other networking library like Alamofire, or anything else, the execute method in RequestType accepts an optional argument named dispatcher of type NetworkDispatcher.
NetworkDispatcher is a protocol that only requires implementing a single method called dispatch:
public protocol NetworkDispatcher {
func dispatch(request: RequestData, onSuccess: @escaping (Data) -> Void, onError: @escaping (Error) -> Void)
}By default, dispatch uses URLSessionNetworkDispatcher that dispatches the request using URLSession. But you can define your own NetworkDispatcher as you want.
To run the example project, clone the repo, and run pod install from the Example directory first.
Conn is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod 'Conn'fmo91, ortizfernandomartin@gmail.com
Conn is available under the MIT license. See the LICENSE file for more info.