This architecture is split in differents layers/concepts 🏋️♀️:
ContextCoordinatorsViewControllersViewModelsRepositoriesNetworkTests
Since I've been learning swift with Xcode at OpenClassrooms online school, I had to create some projects to validate my classes and become graduated.
To build this app, please make sure you have a correct internet connection because it uses api request to receive data from the network. You can clone the repo on your device and open it in your terminal. To avoid heavy file, we created a gitignore file to ignore Pods. Please write $pod install in your terminal at the root of the project. Then cmd + b.
Context is the main object injected everywhere in the app. It has the responsibility to provide a dependencies injected first in the AppDelegate. Every new dependency should be injected through it.
The coordinator is a separate entity responsible for navigation in application flows. With the help of the screen, it creates, presents and dismisses UIViewControllers, by keeping them separate and independent.
The coordinator can, create and run child coordinators too.
Since a coordinator is responsible for the entire flow of a specific flow (or stack), do not create a coordinator per viewController.
The only way of using a coordinator, is to instantiate it (by injecting into it if necessary some specific objects) and call the start () method, and that's all.
The entire logic will be encapsulated by delegation for the rest of the navigation.
In this app there is one MainCoordinator which coordinates from the mainTabBar then 3 separate coordinators which coordinate each screen. SearchCoordinator for the screen weather FavoriteCoordinator for the screen converter CreationCoordinator for the screen translator
First I have installed Alamofire with CocoaPod.
As indicated by its name, this layer provides different tools to make request in an efficient way. First, you have to create a client NetworkRequest and an NetworkRequest.
Then you can create a Route is a func func getURL
The most useful things in this layer are the func request<T> tool ; Which will help you to make requests, waiting for them to response and handle them as easy as you could imagine. The result will be directly provided by the next layer: Repository.
This layer is responsible for calling the Network layer, and managing the data from it, in order to present it to the viewModel.
You can see that on the top of each repository, a protocol RepositoryType will allow us to test everything by dependency injection.
The ViewModel encapsulates the whole logic which doesn't have to be in the ViewController. It's divided in two parts :
- Inputs: Every event from the viewController needs to be implemented in the viewModel, since it's listening for them. The main event which always needs to be added is
viewDidLoad(). - Outputs: After
viewDidLoad(), the viewController is listening for some changes from theviewModel. For this, theviewModelneeds to provide a reactive var for each data/state needed. The main rule is to keep separate the UI logic between viewModel and viewController, so keep in mind that a viewModel can onlyimport Foundation-> reactive var can't provide data fromUIKitlikeUIImagefor example.
If your viewModel needs a Repository, so you'll need to inject a RepositoryType, in order to mock it more easily in the tests.
The last layer and not the least important. But as it is mentioned in its name, a ViewController only exists for control. So, if you want to test it, you'll only provide UI test, since the logic is extracted in the corresponding ViewModel. I recomend to add a custom snapshot to test it correctly. (Not provided in this project).
Please make sure you have an internet connection, since some of them needs to make direct requests, these parts should be for sure splited in a better way later (like launching network test only if the connection is available etc..).
Press cmd+u and let the magic green life be.
Thank you for your time for reading this, I hope that you'll have as pleasure as me to read it and understand the different parts.