Currency Conversion

The idea of this small app is to be used to retrieve a list with some Exchange Rate Quotes from an API and also to provide a very basic calculator to convert an amount between two currencies.

Technologies

• The app is entirely written in Swift
• The UI framework is UIKit
• And the architecture is MVVM
• There are not external dependencies
• A very basic and simple cache is being done using UserDefaults
  • This is for the list of available currencies in the calculator screen
• Unit tests are created using XCTest framework
• The data is provided by Frankfurter
• The network layer was implemented using Combine

Current Scope

At this time, the app has two screens:

• A list of the Exchange Rate Quotes having EUR as a base
• A simple calculator to convert data.

The first screen will always be populated calling the /latest endpoint. An improvement that could be done at this point is to add a cache to prevent this API to be called everytime the user opens the page.

The second screen contains a very basic calculator where the user select the "from" currency, the "to" currency, provide the amount to be converted and, once the API returns the converted value a label is updated with the amount. This conversion is also done by the API and the endpoint that is being used is /latest?amount={amount}&from={from}&to={to}

Improvement

As a path forward for the app, some improvements could be added such as:

• Use CoreData to save all the conversions done by the user and provide a list with them so the user can check the history
• Allow the user to select the base currency on the first screen so they can have more options when checking the rates
• Add some loadings while the requests are being done
• Add some cache to the Exchange Rate Quotes since that, per the documentation, it is only updated once a day
• Add a search field in the first screen so the user can find the information faster
• Implement some proper error handling
• Adapt the layout for other platforms such as iPadOS
• Update the network layer to use Async/Await
• In the first screen, sort the items alphabetically

Side Notes

During the implementation a board in the Apple Reminders was created to track the tasks (the tasks are written in Portuguese) and this is its current state