Articles on Swift, iOS architecture and Domain Driven Design: patterns, concurrency and modelling, with the code to go with them.https://markoengelman.com/https://markoengelman.com/decorator/https://markoengelman.com/decorator/The Decorator pattern in Swift: adding behaviour to existing components without changing them, shown through a token-refresh example.Wed, 27 Sep 2023 00:00:00 GMTClean ArchitectureCompositioniOSSwifthttps://markoengelman.com/detect-users-country-without-accessing-their-location/https://markoengelman.com/detect-users-country-without-accessing-their-location/How to find out which country an iOS app's user is in, without CoreLocation and without asking for their location.Tue, 12 Apr 2022 00:00:00 GMTiOSSwifthttps://markoengelman.com/ddd-aggregates-part-i/https://markoengelman.com/ddd-aggregates-part-i/What an aggregate is in Domain Driven Design, and how referencing other entities by ID affects an iOS app's loading speed and memory use.Fri, 18 Feb 2022 00:00:00 GMTClean ArchitectureDomain Driven Designhttps://markoengelman.com/async-execution-of-long-running-tasks-with-task-api/https://markoengelman.com/async-execution-of-long-running-tasks-with-task-api/Adopt Swift's Task to run long-running operations on a background thread, without changing the existing implementation of the operation.Thu, 13 Jan 2022 00:00:00 GMTCompositionConcurrencyiOSSwiftActorsAsyncMainActorTaskhttps://markoengelman.com/use-swifts-async-without-breaking-the-existing-codebase/https://markoengelman.com/use-swifts-async-without-breaking-the-existing-codebase/How to adopt Swift's async/await APIs where they're needed, without breaking or changing the existing codebase.Mon, 01 Nov 2021 00:00:00 GMTCompositionConcurrencyiOSSwiftSwiftUIAsynchttps://markoengelman.com/how-to-connect-to-wi-fi-device-from-ios-app-using-swift/https://markoengelman.com/how-to-connect-to-wi-fi-device-from-ios-app-using-swift/Connecting an iOS app to a Wi-Fi device with NEHotspotConfigurationManager, and the gotchas along the way.Sat, 14 Aug 2021 00:00:00 GMTiOSHotspotWi-Fihttps://markoengelman.com/ddd-learn-when-to-use-and-how-to-design-entities/https://markoengelman.com/ddd-learn-when-to-use-and-how-to-design-entities/When to use entities in Domain Driven Design, and how to design them in Swift: unique identity, properties, behaviour and invariants.Fri, 19 Feb 2021 00:00:00 GMTClean ArchitectureDomain Driven Designhttps://markoengelman.com/ddd-value-objects/https://markoengelman.com/ddd-value-objects/How value objects differ from entity objects in Domain Driven Design, and how to define their identity and use them in Swift.Fri, 12 Feb 2021 00:00:00 GMTClean ArchitectureDomain Driven Designhttps://markoengelman.com/ddd-anemic-vs-rich-domain-model/https://markoengelman.com/ddd-anemic-vs-rich-domain-model/What an anemic domain model is, what its downsides are, and how to refactor it towards a rich domain model, with examples in Swift.Fri, 05 Feb 2021 00:00:00 GMTClean ArchitectureDomain Driven Designhttps://markoengelman.com/observing-model-changes-using-propertywrapper/https://markoengelman.com/observing-model-changes-using-propertywrapper/An alternative way to observe model changes with Swift's @propertyWrapper, compared against didSet, KVO and delegates.Fri, 29 Jan 2021 00:00:00 GMTSwifthttps://markoengelman.com/how-to-encapsulate-business-rules-using-policies/https://markoengelman.com/how-to-encapsulate-business-rules-using-policies/Encapsulating simple business rules in Swift with policies, instead of hiding them inside methods and properties.Fri, 22 Jan 2021 00:00:00 GMTSwifthttps://markoengelman.com/a-better-way-to-handle-weak-properties-and-memory-management/https://markoengelman.com/a-better-way-to-handle-weak-properties-and-memory-management/Handle memory management in Swift without leaking implementation details into components or reaching for weak properties all over the codebase.Fri, 15 Jan 2021 00:00:00 GMTSwift