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Example iOS app designed using MVVM-C and Clean Architecture. Uses Swift Concurrency.

The app retrieves images for any search query or tag via the Flickr API. It has three modules: ImageSearch, ImageDetails, HotTags.

• Clean Architecture
• Explicit Architecture
• MVVM
• Flow coordinator implemented with closure-based actions
• Dependency Injection, DIContainer
• Protocol-Oriented Programming
• Data Binding using the lightweightObservable<T>
• Closure-based delegation using the lightweightEvent<T>
• Pure functional transformations
• Delegating entity behavior
• Alternative DTO approach

• Reusable and universalNetworkService based on URLSession
• Reusable and universalSQLite wrapper around SQLite3
• Image caching service
• Configurable use ofUIKit orSwiftUI for the same screen
• Advanced error handling
• Unit and integration tests for a number of components from all layers

Presentation (MVVM):coordinators,UI elements,SwiftUI views,UIKit storyboards,ViewControllers,ViewModels

Domain:entities,use cases,services,interfaces

Data:entity repositories,APIs,API/DB interactors (or network services and persistent storages),adapters

Detailed architecture overview

ImageSearch module:

* searchImagesUseCase.execute(imageQuery)* imageCachingService.cacheIfNecessary(data)* imageCachingService.getCachedImages(searchId: searchId)

ImageDetails module:

* getBigImageUseCase.execute(for: image)

HotTags module:

* getHotTagsUseCase.execute()

ImageCachingService implements the logic for caching downloaded images and freeing memory. This helps keep the app's memory usage under control, since there can be a lot of downloaded images, and without caching, the app could quickly accumulate hundreds of MB of memory used. Downloaded images are cached and read from the cache automatically.

• SwiftEvents - the easiest way to implement data binding and notifications. Includes Event<T> and Observable<T>. Has a thread-safe version.
• URLSessionAdapter - a Codable wrapper around URLSession for networking
• SQLiteAdapter - a simple wrapper around SQLite3

For a Swift 6 version with SWIFT_STRICT_CONCURRENCY = complete, see theswift6 branch.

iOS 15.0+, Xcode 13.0+, Swift 5.5+