iOSDevUK 2022

5th - 8th Sep 2022 | Aberystwyth 󠁧󠁢󠁥󠁮󠁧󠁿🏴󠁧󠁢󠁷󠁬󠁳󠁿

10th anniversay of the conference!

I ❤️ Swift Concurrency

Tunde Adegoroye

• Annotate with @MainActor to return from a function on the main thread
• async let to run in parallel
• Taskgroup to run child tasks in parallel
  • No order
  • Taskgroup finishes when all children finish
• Actor can safely update it’s state across threads
• Tasks have
  • Priority
  • Relationships
  • Handel cancelation
• Xcode 13.2 added backwards support
• Course on Youtube tundsdev

The bleeding edge of SwiftUI

Malin Sundberg

• Orbitapp is for macOS + other platforms
• Mercury weather app
• Attach a presentationDetent to a sheet, and add fractional size
• Can add a drag indicator if just one size
• View that fits allows you to reuse subviews. Use Grid or Vstack etc
• SwiftCharts and Widgets are SwiftUI only

Remember Me: A Guide to Memory Debugging

Luke Parham

• Memory impacts everything
• Frequent causes of crashes
• iOS & watchOS don’t use paging to free up memory
• Jetsam monitors memory pressure
• Kills apps to free up memory
• memgraphs snapshot memory
• Open in Xcode or cli
• Can snapshot over time to analyse changes
• On macOS use leaks cli for any app
• Leak when lose track and forgets to free
• Retain cycles
• Abandonment is not a leak
  • e.g. a big image hanging around not being used
  • Cached but not used
  • Cannot be identified with a tool
    1. Get a memgraph
    2. Start with footprint to see where
    3. Look at dirty memory Malloc
    4. Malloc-history where allocated
    5. Heap mmap —trace tree
• Less likely to happen in Swift, but in older Obj-c

Unintended Consequences

Steve Westgarth

• The Engineering Leader podcast
• Changing a mental model is risky
• Release Later (reduce risk of unintended consequences) vs Release Early (maximise opportunities)
• Should we implement tracking
• Is it unethical?
• The software we create is our shared collective responsibility
• Consider what the unintended consequences could be in your company

Becoming an iOS Dev, again

Michał Waśniewski

• Split in progression track Engineer vs Management
• Management 3.0 Moving Motivators
• More freedom?
• Not a promotion, it is a role change

Next Step: Management?

Leah Vogel

• Management != Leadership
• “Guides a team to execution”
  • Willingness to give feedback
  • Team building + cohesion
  • Execution to get stuff done
• You should like people a lot
• Success is harder to define as a manager
• Less peers and can feel lonely, so be part of a community
• Hands on manager is a nightmare
• Hands warm development
  • Logs. Bugs. Code review.
  • Not critical path.
• You don’t need to be a manager

NHS COVID-19 app: delivering a resilient app at speed

Mo Ramezanpoor

• Singapore, Norway, UK all tried with core bluetooth
• Apple + Google defined Expose Notifications API
• Swift packages to segregate prod + internal builds
• Everything injected
• Good test coverage
• Scenario picker

Mysteries of SwiftUI Text View

Natalia Panferova

• Worked one SwiftUI at Apple
• Text inherits the context from its parent components
• Text("") uses a string literal localised string
• SwiftUI Text can parse Markdown
• Release offset timer date style interpolates as live
• Nest text for different styles with modifiers
• Can concatenate, but better to interpolate to allow system to re-order words for other languages
• Can override styles
  • Those applied in interpolation take precedent
  • Reset but using nil

Indie app business models - a better ad-supported option

Jake Nelson

• Not evil ads
• Sell an add slot like a newspaper
• Uses expecting Free apps
• Some users only go for free
• Very Free without any monetisation
• Paymeium pat upfront plus consumables
• Start with free then change to paid later. Helps to get feedback early
• Combine methods
• Privacy friendly ads to monetise free users

Hey Siri!

Adrian Strahan

• Snonav audience guidance for routing
• Siri + Siri Shortcuts
  • Report last instruction
  • Change Sky route
• Pronunciation: Piste -> Peeste

Swift your personal website using Publish

Danijela Vrzan

• Static Site Generate (SSG)
• JAMSTACK = JS API Marksup
• Use a CMS for anything dynamic
• Publish by Swift Sundell
• PLOT is a DSL for type safe HTML.
  • Can use in an iOS app as well
• Define and render using SwiftUI-luke syntax
• INK parses markdown to HTML

Spark your creativity: the power of iPad Playgrounds

Anna Beltram

• Break out of habits to reform creatively
• Builds something in Swift Playgrounds
• Not just at your worklatp on Xcode
• Swift Playground separate app on iPad + macOS
• Can build a full app and launch on App Store