UIKonf 2020

18th - 19th May 2020 | Remote 🖥

Held remotely using Hopin. A mixture of Youtube live streaming, screen sharing, Zoom and in-browser video calling.

Videos here: UIKonf - YouTube

Who can say they have learned Swift?

Paul & Sophie Hudson

• “Who can say they have learned Swift?” No-one can, there is too much to keep up with!
• Swift can evaluate new language features implemented first in other languages.
  • Swift can therefore benefit from their hindsight.
• Community should be more welcoming to other languages developers and newbies.
• We should add citations to talks, blogs etc as otherwise it looks like we people just know and this can be discouraging to newbies.

Building a mobile-based startup business

Dal Rupnik

Building a mobile-first startup business - Speaker Deck

• Dal created a company to help children with speech problems.
• Founded company with other people who also had speech problems as children.
• Each person in the company had technical knowledge, but no knowledge of speech therapy or starting a business.
• You should validate an idea as quickly and as cheaply as possible.
• Startups often go through several MVPs and rewrites.
• You should look at similar apps to choose the right business model.
• Look for financial help from angel investors, private seed camps, accelerators and government funding.
• Remember that is unlikely you have a truly uniquer app.
• You could ask an influencer for help in promoting your app.
• You shouldn’t spend too much time on unit testing your MVP.
• Choose the right backend for your MVP. Consider:
  • What do you need as a minimum?
  • What can you afford?
  • What do you have preexisting technical knowledge of?

Prepping For a SwiftUI Future

Veronica Ray

Prepping For A SwiftUI Future - Speaker Deck

• Adopting MVVM (or similar) helps moving to SwiftUI.
• Swift UI only work on iOS 13 and above.
• For best results use SwiftUI and Combine together.
• Coordinator pattern ay not be suitable for SwiftUI. See this blog post: Clean Architecture for SwiftUI - Alexey Naumov

The Multi-Threaded Asynchronous Parallel World of Swift

Leo Dion

GitHub - leogdion/AsyncWorld

• Concurrent programming intersperses tasks.
• Parallel programming dedicated tasks to a core.
• Both approach can be combined.
• A process is 1 app running in the the OS.
• Each process can be split into threads, for example
  • Networking
  • UI
  • Background processing
• Asynchronous (NS)operations are hard and feel tacky.
• It is hard to repack errors and results.
• C# and JS use Promises and Futures. Offer some advantages:
  • No “callback hell” or “pyramid of doom”.
  • Can use functional functions for converting outputs.
• Swift Nio V2 has Promises and is used in server side Swift such as Vapor. Not suitable for iOS or macOS.

Rich Text, Core Text

Rob Napier

Slides

• Swift has great handling of unicode and therefore emojis.
• A “code point” maps a number to abstract characters.
• This is a fundamental unit of language, independent of how it is drawn
• Emoji come from Japan, from a time where there were no colours on phone screens.
• A variation selector is used to modify an emoji.
  • Selector 15 is text version. This baselines the emoji like regular text.
  • Selector 16 is emoji version. This makes the emoji “hang” in the square.
• Emojipedia documents all the emojis available.
• Some characters might have 2 unicode records. For example é:
  • Could be the combination of e and an accent
  • Or é in its own right
• Is possible to apply accents to emoji, but it looks weird.
• Zalgo is a method for combing random unicode together in the range 0x0300…0x036f
• Combine a number with keycap to add a box around a number.
• Create flags using region letter. For example: region-u + region-s = 🇺🇸
  • ISO committee wants to stay out of politics regarding what is and what is not a recognised country.
• Create regional flags (only works for GB currently). Combine:
  • Black flag: 🏴
  • Then region: gb
  • Then sub region: sct
  • Then cancel
  • = 🏴󠁧󠁢󠁳󠁣󠁴󠁿
• Emoji people accept a skin tone and gender modifier.
• Skin tone modifiers attach to any character, but only emojis actually combine them. Others keep them separate characters.
• There is a total of 25 combinations for the family emoji.
• Apple adds more details for their emoji glyphs at higher resolution. The largest keyboard on iOS ~47K glyphs!
• GitHub - akfreas/emoji-extractor-plus: Extract emojis from Apple font in PNG format

Cross-platform Collaboration Patterns

Miriam Busch

Cross-Platform Collaboration Patterns - Speaker Deck

• In a cross-functional team meeting only certain people are engaged as not all platforms are discussed at the same time
• 1 platform is often built after the other one, therefore playing the “catchup game”
  • The platform catching up has freedom in UI as one 1 platform has been delivered.
• From a technical point of view this is often harder and is better to consider everything up front at the same time.
• Naming is hard but is super important for everyone (code, documents, business etc) to agree on shared language.
• Unified UX ≠ unified UI.
• A design system can help in multi-platforms.
• Developers sometimes don’t like high fidelity designs as they know the canonical way to implement a feature better than designers.
• Managers should do code review!
• Cross platform pairing and code review for iOS and Android works.
• The API for iOS and Android is often shared..
  • Defining interfaces is quite waterfall but work.

Building a Programming Language in Swift

Chris Eidhof

• Presentation done from a forest in 1 take!
• Building a language from scratch is a lot of hard work, but can be fun to learn!

Swift Scripts: Zero to Hero

Federico Zanetello

Swift Scripts: Zero to Hero 🦸🏼‍♀️ - Speaker Deck talks/2020 Swift Scripts Zero to Hero at 52f0e697994c0528388b97da99f66f1440ef2e09 · zntfdr/talks · GitHub

• Can create scripts in Swift as an alternative to using Ruby or Python.
• Create a Swift script through spm as an executable. Use the CLI rather than Xcode.
• main.swift is executed luke in a Swift playground.
• Can run from the terminal or open in Xcode.
• Get command line arguments using CommandLine.Argumenents
• Use exit() to terminate with EXIT_FAILURE
• Use readLine() synchronous function to get for user interaction.
• Environment variables from ProcessInfo.environment
• User FileHandle to get piped data.
• ArgumentParser library is from Swift Team.
  • Add as a dependency.
  • Managers parsing arguments, flags etc for you.
  • Automatically prints errors if args are missing.
  • Prints out --help text for free.
• Define a ParsableCommand
  • @Argument with name and help text.
  • @Flag also supported.
  • run() function that runs have all args are parsed.
• Tool Support Core - Basic and Utility - to add a progress bar, with updates, into the CLI.
• Using build -c release releases copies to the local/bin
• Use the runloop and Dispatch.main to do async work.

Talk: Data Trusts: What, Why, How?

Anouk Ruhaak

Open Letter - Anouk Ruhaak - Medium

• Individuals acting independently for their own privacy also has collective consequences for everyone.
  • Similar lesson during Covid19 pandemic.
• Privacy: control over appropriate flow of information into given context. You may not want this shared in another context.
• “Decision fatigue”:
  • Who has time to think about sharing data (i.e. cookies) with each specific site?
  • You just say “Yes” which is a flaw.
  • Also begs the question: what is the point of a “Yes” if I can’t answer “No”?
• Individual vs collective interest often decided on by the government.
• A Data Trust is a legal instrument. It has fiduciary functions:
  • Duty of loyalty - to the data subjects.
  • Duty of care - not to be neglected.
• Data Trustees make decisions that should be “good”. Example:
  • Data Subjects may be people with a disease who share their health data with a data trust.
  • The Data Trustees must seek to further the goal of curing the disease, not to make money.
• Data Subjects have collective bargaining power much like a union.
• How do trustees get chosen? Elected?
• How do they decide things? Voting?
• Data Trusts seek consent, like in hospitals.
  • Patients do not sign off every eventuality before surgery.
  • Instead patients sign off high level risks, then they trust the surgeons to make the right decisions.
  • Surgeons are still accountable.
• Developers are often the first line of defence to make sound privacy calls.
  • Customers and governments may not make sound decisions.
  • Developers should ask these questions.
• Example - contact tracing for Covd19.
  • Bad time fo governments to be experimenting with big data
  • Government could abuse this opportunity as there will be less scrutiny.
  • Apple + Google protocol is de-centralised and is probably better.
  • Contact tracing might not be the thing we should be contracting our attention on right now. Would be better to get testing infrastructure and solve other more pressing risks
• Facebook have an “overview board” which is similar to a Data Trust.
  • This does not have a duty to the shareholder.

We need to talk about Websockets

Kristaps Grinbergs

• Websockets = TCP IP Sockets + HTTP Requests
• Fully supported by Apple in iOS 13+
• 1 sides talks while the other side listens.
  • Two way
  • Single connection
  • Persistent
  • Low latency
• Can be used for real time data transfer.
• Connection handshake uses a GET request.
• The Starscream Swift library conform to the websocket protocol.
• Can be tricky to debug.
• Useful tools for debugging:
  • Charles fo rmacOS.
  • Proxyman for macOS
  • Cleora for iOS supports web sockets + HTTP debugging
• Long polling can be more stable and reliable than websockets.
• Radio will always be on so it could be bad for battery life .

State Driven Development - The Beauty of Enums in Swift

Conrad Stoll

State Driven Development - The Beauty of Enums in Swift - Speaker Deck

• Bools are often used through a project to denote state.
• However it is not always clear
  • How bool values change,
  • What the dependencies in state changes are.
• Multiple bools for state adds complexity and it an opportunity for bugs to be introduced.
  • It is possible to have more permutations of bools than there are valid states.
  • “Tangled web of state”.
• Enums can be used instead.
• They help developers ask specific questions and prevent invalid states.
• Tempting to add a bool for something simple. Instead always use an enum as this is more extensible in the future.
• An enum can describe the lifecycle and the state of the program .
• An enum represent the single source of truth for view controller states.
• GitHub - pointfreeco/swift-enum-properties: 🤝 Struct and enum data access in harmony.)