Currency

App Description

• Currency is a currency exchange rates converter.
• Currency supports almost currencies
• It based on https://openexchangerates.org/

How to use the app

Open the app with the Internet -> The app will display all currencies and base currency above

• Type a number to the box -> The app will exchange and display all currencies
• Type a keyword on the search box -> The app will filter the currencies list by keyword It supports offline mode

How to build the app

• Should open project by Android Studio
  
• It can config OPEN_EXCHANGE_RATES_SERVICE_APP_ID_PROD if we have a specific key for Production build

Challenge when building the app

I faced 3 problems when I build the app:

1. App Architecture: I would like to make an app with architecture to easy maintenance and scalable and testable. So I decided on a modularization app and applied Clean Architecture, MVVM. More details below
2. Dagger: There are many modules in the App Architecture, so it's hard to connect with each other. I created a BaseComponent in the Base module and every feature module need to be dependent to BaseComponent
3. Paging list with online and offline mode: I used the Paging library in Android Jetpack and created a repository that responses to decide online (data remote by Retrofit) or offline (data local by Room)

I split the app into 2 modules:

1. Base Module: BaseActivity, BaseFragment, BaseComponent,...
   
2. Design System Module: Colors, Styles, Spacing, Icon Size, Font Size,...
   

• I used the modules to show, how I work with multi module application

Advantage of Modularization:

• Smaller components are easier to maintain.
  
• Decrease build times
  
• Components with high cohesion can be re-used again.
  
• The team can decide architecture on own features
  
• Some libraries in the project: ViewBinding, Dagger, Retrofit. Jetpack components: ViewModel, Navigation, Paging, Room

Test

• I don't have enough time to write all tests, so I try my best.