Step-by-Step Guide to Building a Structured Swift Application

Building a structured application doesn’t start with writing code, but with planning the architecture. In this article, we’ll look at a step-by-step approach to building an application with a clear separation of layers and logic.

Step 1: Planning the structure
Before you start, create a basic folder structure:

• Models
• Services
• ViewModels
• Views

This allows you to immediately separate responsibilities.

Step 2: Creating the model
The model describes the data. For example, if the application works with a list of tasks, a Task structure with properties is created.

The model should be independent of the interface.

Step 3: Adding a service
The service is responsible for working with the data: saving, loading, or processing.

It is important that the service does not know about the interface. It only returns or accepts data.

Step 4: Creating the ViewModel
The ViewModel is the intermediary between the service and the interface.

Its role:

• get data from the service
• prepare it for display
• handle user interaction

Step 5: Implement the interface
The interface should only display information and pass actions to the ViewModel.

It is important to avoid direct logic in the View.

Step 6: Manage state
Each screen should have a clear state:

• loading
• done
• error

A clear state model avoids chaotic checks.

Step 7: Test the logic

The ViewModel logic can be tested separately from the interface. This simplifies maintenance and updates of the application.

Step 8: Scaling
When new features are added:

• new services are created
• models are extended
• the basic structure does not change

This is what makes the application scalable.

Conclusion
A structured approach allows you to:

• simplify support
• reduce errors
• add new features faster

The key principle is a clear separation of layers and responsibilities. When each component fulfills its role, the application becomes understandable and predictable.