Apple Introduces SwiftUI; So What?

Shortly after Apple announced SwiftUI a twitter thread erupted discussing a hypothetical Sharp UI. It was positioned an alternative for declarative ui development, across Xamarin applications in C# or F#. If Apple has SwiftUI, perhaps we’ll Microsoft rollout # UI (Sharp UI) for as a new method for building user interfaces in @xamarinhq apps with … Continue reading “Apple Introduces SwiftUI; So What?”

Shortly after Apple announced SwiftUI a twitter thread erupted discussing a hypothetical Sharp UI. It was positioned an alternative for declarative ui development, across Xamarin applications in C# or F#.

What’s interesting is that both Google, with Jetpack Compose, and now Apple, with SwiftUI, have joined the modern evolution of app development by introducing a declarative way to define user interfaces. Declarative UI development has been around for a long time. For example, take any of a number of XAML based frameworks that Microsoft has produced (something completely missed by Martin’s post on What SwiftUI Means for Flutter who incorrectly claims declarative ui development was invented in React by Facebook).

So why now? Why is it that Apple, Google and Microsoft have all recognised that declarative UI is the way forward?

XAML as a Declarative UI

The back history of XAML goes way back to the WinForms days. It was common for developers to fight the IDE in order to wrestle control of the window layout. XAML was supposed to fix everything. It is not designed for humans (much the same way storyboards weren’t designed to be manually coded). XAML id designed for developer tooling such as Blend.

A few XAML frameworks later and what we find ourselves in Xamarin.Forms. The XAML is non-standard version. It is similar, yet in ways dramatically different from every flavour of XAML that predates it. The industry has moved on from trying to get previewers, such as Blend, to work. The developer community favours hot reload and the ability to adjust layout within a running app.

I’m sure that Xamarin.Forms will get there with XAML but is it too much of a liability? Should we look for an alternative?

Declarative UI in Code aka #CSharpForMarkup

Following down the discussion on the SharpUI twitter thread we end up discussing an alternative to XAML, which is declaring UI in code. This sounds awfully familiar to what SwiftUI or Flutter is doing, except this is for Xamarin.Forms.

Normally I would be against using declarative ui development in code as I feel that it becomes harder to separate the UI logic from the application logic. However, having spent time reviewing CSharpForMarkup I feel that it is a viable alternative to XAML and perhaps even removes a layer or two of the cognitive load Adam talks about

Cross Platform is the Future

At Built to Roam we spend a lot of time discussing app strategy with our clients. We often talk about the spectrum of app development options ranging from native all the way through to web. Almost the first thing we do is to discount and remove from discussion both native and web. If the client wanted a web experience, they would have gone to a web development agency, instead of come to us. We’re not going to recommend building a native application, even in Xamarin, when we should be considering cross platform options.

If you’re following the announcements about SwiftUI, or Jetpack Compose, sure go ahead and read up on them. Then pack them into their single platform box and put them back on the shelf. Take our your cross platform tool of choice (React Native, Flutter, Xamarin.Forms etc) and get back to building high quality amazing apps for both iOS and Android.

Nick Randolph @thenickrandolph
If you have an app and want to go cross platform, or are just starting you app development journey, contact Built to Roam.

App or not to App

App or not to App

Following my last post there were a couple of interesting tweets that made me revisit (again) the discussion of whether building an app is the right thing to do. For example, @GeoffreyHuntley said:

Decision time:
– #0 Don’t make an app unless you absolutely have to.
– #1 React + React Native (insane productivity)
– #2 Xamarin (stagnating tbh)
– #3 Flutter (innovator – watch this space)

To be blunt, options 1-3 are all semi-painful – I’m not going to go into detail as to why, as that’s not the point of this post but needless to say that each one has their pros and cons, and none are what you’d consider an ideal development experience. Option 0 sounds like a great option and with the rapid development of Progressive Web Applications (with service workers being included by both React and Angular) it really does seem that not having to build an app is the way to go.

Ok, but in that case, when would we build an application? Before we answer this, I think it’s worth revising what the notion of an “application” or “app” actually means. If you do a search for “App” on Wikipedia you get a number of responses:

  • Mobile app, software designed to run on smartphones and other mobile devices
  • Application software that causes a computer to perform tasks for computer users
  • Web application or web app, software designed to run inside a web browser

(And particular note that the term “website” is not included here as according to Wikipedia a website is “a collection of related web pages” – personal opinion: if you still building for the web using the traditional post-back model (yes, looking at you ASP.NET) you’re building a website, not an app).

Let’s ignore for the moment the distinction between mobile, web or any other qualifier about the type of an application or the target platform and instead, let’s focus on what an application is. According to Wikipedia an Application is software that causes a computer to perform tasks for a user. This is a pretty wide definition and essentially encompasses most software, whether it be a command line application, browser or window based application. However, if you were to ask most people what they thought an “App” was today, they’d probably give an answer that relates to installing an application from the Apple, Google or Windows Store – it seems like the notion of an App is in somehow attached to the distribution model.

If we look further into this, there are a variety of distribution models:

– An application that you simply download from the Internet and just run (it might download as a Zip file but the important distinction here is that there’s no installation process and no Store managing the application). This is by far the simplest distribution model. However, these days few applications are distributed this way as most operating systems distrust downloaded files from the Internet and will refuse to run them without them being “unblocked” first.

– An application you download from the Internet and then install. For Windows and MacOS historically this was the most common way for applications to be distributed. The operating system didn’t have a built in distribution mechanism, such as a Store, but they did support a model for applications to be installed and uninstalled. The danger of this model, is that, similar to just downloading and running an application, an application that is installed could have wide-reaching access to the host operating system. Over time this model has be adapted and additional security (for example User Account Control on Windows) limited what an installed application could do

– An application you install from a Store. Whilst this model did exist prior to the iPhone, it wasn’t really until the App Store launched that the notion of a single curated Store became mainstream. Now, most platforms have a Store where you can browse, search and install apps to suit your every need. Depending on the platform, the process for submitting, certifying and publishing applications varies, with different levels of quality and policy controls imposed in order to try to maintain a high quality bar for apps. The Store also takes on responsibility for distributing updates to application as they become available, as well as providing a mechanism for developers to charge for their applications.

– An application you load in the browser. Most people don’t really consider websites that they navigate to in the browser as applications. However, websites are becoming highly functional and most no longer require a full post-back in order to load more content, improving the usability. In fact, browsers have tried to prompt web sites as pseudo-apps by allowing users to add a web site to a list of applications (for example the “Apps” icon that appears within Chrome under the address bar).


– An application you install via the browser. In contrast to adding a website to a list of applications within the browser, installing a website via the browser allows the website to take advantage of a lot of the benefits of applications installed via a Store. They can appear as an icon on the home screen (or list of applications installed on the device); they run without the browser chrome; they can receive push notifications and much more.

So the question is whether the distribution model is what defines what an “App” is?

When we embark on building an application do we need to lock ourselves into one of these distribution models, or can we pick multiple, or all of these distribution models. Or, is the distribution model different for each platform? To answer this we really need to consider the pros and cons of each mechanism and the corresponding audience reach it gives us, and whether it makes sense to choose a particular distribution model.