When you build a house, what’s the first thing you need to do? Lay a foundation. The foundation type depends on how big the house will be, how many floors it will have, and what construction material you will use to build it. Now when it comes to mobile software before you start working on its development, you need to create an architecture for the same. The architecture will persuade the application’s scalability and its whole structure.
There is no perfect architecture. Every project is unique, with its own requirements. The elements that influence the architecture are similar for Android and iOS. In this article, our main focus is on Android Architecture.
Here are a few things which impact the architecture:
- Technology Stack
- Tool Set, server infrastructure, databases, and SDKs
- Usage of cloud technologies
- Integration of third-party services like maps, payment gateways, etc.
- Future Plans
- Type of project
- The expertise of the developers
[Also read: iOS Architectures]
What Ascertain a Good Android Application Architecture?
What do we want to attain when we design architecture? There are four things every developer wants to achieve with their architecture.
- Code reusability and testability
Now that we’ve explained the substantial principles and goals of architecture, let’s talk about each type of architecture in detail.
Model-View-Controller is quite a famous type of architecture. In line with this architecture, the developers systematize functionality into three main categories. This type of architecture divides the parts of an app by purpose according to the separation of concerns principle.
Model – The model specifies the terms your application operates. Stores all the information your app holds.
View – Accountable for how your app looks. The view contains the UI of your application.
Controller – Commands the view how to behave. The controller holds the business logic of your app.
MVC architecture has two options:
- A Supervising Controller
- Passive View
When we talk about a supervising controller, it interacts with the model and doesn’t need the presenter’s participation. Whereas in the passive view the presenter needs to update the view because that reflects changes in the model. In mobile development, a supervising controller is almost never used. Check the android architecture diagram that demonstrates how MVC works.
Here, you can check out the pattern of the MVC with a supervising controller. The view depicts both users and reverses requests. The controller receives incoming data and the view depicts the output. Both of these parts exchange information with each other.
MVC is a flawless architecture for small projects, but it has a pretty simple structure that won’t cover all the features of a big project, for example, a business app or an app for healthcare or banking.
The Model-View-Presenter (MVP) android architecture makes testing of the applications very easy. The presenter of the application can be used multiple times and it has the ability to represent several interfaces.
Model-View-Presenter complies with the principle (Separation of concerns). This principle separated the interface of the app from the model. It is popularly being used to build user interfaces.
Although, to effectively build an interface, you should use MVP or MVC as your motivation, not apply these development patterns directly.
Developers use two elements to make MVP architecture work efficiently:
- Use Cases
- View BIndings
Model-View-ViewModel or MVVM is another android architecture. If you look for the first time it will remind you of the MVP pattern, because both of them separate the view from business logic. But there is a huge difference.
- MVP makes the view independent from a specific user interface platform.
- MVVM is focused on the event-driven programming of user interfaces.
This concludes that android architecture MVVM works better when you need to make fast design edits.
Model–View–ViewModel architecture consists of:
- Model – Represents either a real state content or a data access layer that represents the content.
- View – Reflects user actions and informs the ViewModel
- ViewModel – Transfers data according to what the View requests
In the Model View Presenter pattern, the presenter tells the view what to display for the user to view. In Android MVVM, the ViewModel streams events that the View can bind to. So there is no need for the ViewModel to address the View.
There is another android app architecture you can use for your mobile application is Model–View–Intent, or MVI. MVI can only work with RxJava – a Reactive programming library.
Although the separation of concerns principle needs some effort at the early stage of mobile app development, it’s a great way to make your code high-quality, scalable, understandable, and reliable.
Development of android app architecture patterns like MVVM and MVI can help to improve the scalability of your mobile app, but note that they’re dependent on RxJava.