Tag Archives: software development

QCon London: the Ethics track and the psychology of software

The most significant thing about the Ethics track at QCon London, a software development conference I attended last week, is that it existed. I can recall ethics being discussed at QCon in previous years (including a memorable appeal by Martin Fowler at Thoughtworks about rectifying the gender imbalance in IT) but not a specific track.

Why does ethics matter more today? Ethics has always mattered, but the power of software over our lives is increasing. It is possible be that algorithms at Facebook, YouTube and Twitter influenced the result of the last US election and the UK’s Brexit referendum. Algorithms play a large role in influencing many of choices, what to buy, where to eat, where to stay, which airline to book, which vendor to use.

Software also consumes more of our time than ever, as we constantly check our phones for notifications, play games or read online content.

The increasing importance of AI (Artificial Intelligence) also raises ethical questions. Last week I attended the Re-work AI Assistant Summit, also in London. One of the sessions concerned “Building an AI Friend”, presented by Artem Rodichev from Replika. The demos were impressive, showing how a bot can be engaging and help users to talk about what matters to them. I asked though if the company had thought about ethical issues, for example if a child became attached to a bot without realising it was non-human. The answer I got was in effect a blank look, followed by the statement “we have a minimum age limit of 7”. The company has no announced business model, but I would encourage it to form an ethical policy early as these things are hard to bolt on in retrospect – as Facebook is discovering today, in the aftermath of the exposure of how its personal data is being misused by third parties.

AI is also poised to take over more jobs previously done by people. This could be a great liberator for humanity, or alternatively divide society even more deeply into haves and have-nots.

We need more ethics discussion then; but is it too late? Well, it is never too late to improve matters, but perhaps much harm could have been avoided if the industry had focused on this earlier.

I attended a talk by Alexander Steinhart (a technologist at ThoughtWorks) on the psychologist’s perspective on ethics in technology.

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Steinhart talked about addiction. “We all want to unplug, but cannot”, he said.

“Now we are all connected. On average people are nearly three hours online every day. They check phones every 7 to 15 minutes. Many people have difficulties in finding the right balance.”

When is a habit an addiction? When it “gets into the way of your life and you can’t do anything else, and when you try to change behaviour you don’t manage,” said Steinhart, mentioning that “distraction” is identified as a risk by many people today, including teenagers.

Interruptions and distractions are detrimental to our productivity and also a source of stress, he said. Once you are distracted, it takes 20-25 minutes to recover your focus. “Take care that you are not connected all the time.”

Unfortunately we have also developed an “attention economy” where web sites and apps are rewarded for holding our attention and they have evolved to do that effectively.

A great way, apparently, to get us addicted is to have mechanisms that only occasionally reward us. We will try and try again in hope of reward. Lotteries are like this. So are slot machines. So too, says Steinhart, are things like notifications in apps, or the action of pulling down to refresh emails or other feeds. Most of the time we get nothing of value and we know that. But occasionally something really good arrives. The possibility keeps us hooked.

Another difficulty is that humans do not always cope well with abundance. When a previously scarce resource, food for example, becomes abundant, logically what should happen is that we become more discriminating, selecting only the best and discarding the rest. In practice though this is not the case, and we have seen the ascendance of junk food that does us harm.

We now have abundant information. Answering a question that might once have required a trip to the library or several phone calls can now be done in an instance. That is fantastic; but are we coping well? Somehow, instead of becoming more discriminating about the sources and value of available information, humanity is prone to consuming more and more information of low quality, whether that is banal time-wasting or actual falsehoods and information that is intended to deceive or mislead us.

Steinhart argues that we have moved into a new technological era but have not yet learned how to manage it. He draws an analogy with urbanisation; it tool mankind a while to learn how to build cities that were agreeable places in which to live.

Human needs includes some that are will served by today’s technological landscape. We need to experience “all of the different senses, to small, to taste.” We need privacy and solitude. “If you put managers alone for one hour in a room with nothing to do, they make better decisions the rest of the day,” claims Steinhart. We also need conversations, not just connections. “There is so much human interaction that you cannot digitise, like looking someone in the eye” he said.

How does this translate to ethics in technology? We need positive computing and software design that is “aligned with human goals,” he said.

Free and open source software is helpful in this respect, because the goals of the software are aligned with our needs rather then profit.

What can software developers do? “It is not your fault that technology is distracting,” said Steinhart, “but it’s your responsibility to change something.”

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It is interesting to imagine what software might look like if designed for human needs rather than business interests. Steinhart’s ideas are around making software quieter, designed to get out of our way rather than to interrupt us, smartphones that encourage us to leave them alone, and of course to avoid anti-patterns which feed addiction or deliberately try to trip us up.

I noticed this tweet today about how an Amazon app behaves when you try to cancel. The user clicks Cancel subscription and gets this:

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The following screen reverses the button colouring so that if you trained yourself to tap the faint button, you actually do the opposite of what you intend:

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Until the last screen (there’s another one?) where they switch again:

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This was not in Steinhart’s talk, but it seems a good example of software designed for the business and not for the user.

I have seen a similar pattern in Amazon’s web checkout where you have to click carefully to avoid being signed up for Amazon’s Prime subscription by accident. Not good.

Ethics and technology

This post is long enough; but there is, I hope, much more to say on this subject.

Despite enjoying Steinhart’s talk and others in the Ethics track, I was not encouraged. We need, of course, regulation as well as more principled businesses, and we do not know what such regulation should look like, nor how to implement it.

One thing though is worth repeating: if as a software developer you are asked to do something that is ethically unacceptable, you should refuse. Professional standards include more than quality of coding.

A week of QCon: introduction

I attended QCon London last week and found it fascinating, but have not written as much about it as I intended because of various other deadlines. In order to address this I will do a quick daily post for the next week or so.

QCon is a software development conference run by InfoQ. It is vendor-neutral and focuses on large-scale enterprise development as well as future trends, language choices and changes, software architecture and more. If you delve into the history of the event it has championed techniques including Agile development, Service Oriented Architecture, Microservices, and now AI. The event has a culture and an ethos, which is something to do with human-centred software, team communications, taking hte side of the user, aversion to unnecessary complexity, and constant exploration of emerging technology.

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Laura Bell of SafeStack speaks at QCon London on Architecting a Culture of Secure Software.

QCon, like many other events, encourages attendees to give feedback on sessions they attend. At other events I have often seen forms with several categories and questions like “How well did the speaker know their subject” and “What was your biggest takeaway from this session”? While such questions are reasonable, the problem is that they are too difficult and time-consuming and therefore not many respond, or the responses are of low quality. The QCon organisers decided years ago that the only feedback system that works is to have attendees vote good, indifferent or poor as they leave. This used to be done with coloured paper and is now electronic. I mention this because it says something about the event culture: let’s prefer something that works and is not a burden, despite the seeming crudity of a 1-2-3 scoring system. And of course even such basic information is highly valuable in discerning which sessions were most appreciated.

The event prefers practitioners, engineers and team leads over evangelists, trainers and consultants. It attracts a particularly able audience:

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Of course you can learn plenty outside the actual sessions by chatting to other attendees.

Up next: technical ethics at QCon London.

HackerRank survey shows programming divides in more ways than one

Developer recruitment company HackerRank has published a survey of developer skills. The first place I look in any survey is who took part, and how many:

HackerRank conducted a study of developers to identify trends in developer education, skills and hiring practices. A total of 39,441 professional and student developers completed the online survey from October 16 to November 1, 2017. The survey was hosted by SurveyMonkey and HackerRank recruited respondents via email from their community of 3.2 million members and through social media sites.

I would like to see the professional and student reponses shown separately. The world of work and the world of learning is different. This statement may also be incomplete, since several of the questions analyse what employers want, which suggests another source of data (not difficult to find for a recruitment company).

It is still a good read. It is notable for example that the youngest generation is learning to code later in life than those who are now over 35:

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I am not sure how to interpret these figures, but can think of some factors. One is that the amount of stuff you can do with a computer without coding has risen. In the earliest days when computing became affordable for anyone (late seventies/early eighties), you could not do much without coding. This was the era of type-in listings for kids wanting to play games. That soon changed, but coding remained important to getting things done if you wanted to make a business database useful, or create a website. Today though you can do all kinds of business, leisure and internet computing without needing to see code, so the incentive to learn is lower. It has become a more specialist skill. It remains valuable though, so older people have reason to be grateful.

How do people learn to code? The most popular resource is Stack Overflow, followed by YouTube, with books coming in third. In truth the most popular resource must be Google search. Credit to Stack Overflow though: like Wikipedia, it offers a good browsing experience at a time when the web has become increasingly unpleasant to use, infected by pop-up surveys, autoplay videos and intrusive advertising, not to mention the actual malware out there.

No surprises in language popularity, though oddly the survey does not tell us directly what languages are most used or best known by the respondents. The most in demand languages are apparently:

1. JavaScript
2. Java
3. Python
4. C++
5. C
6. C#
7. PHP
8. Ruby
9. Go
10. Swift

If you ask what languages developers plan to learn next, Go, Python and Scala head the list. And then there is a fascinating chart showing which languages developers prefer grouped by age. Swift, apparently, is loved by 75% of those over 55, but only by 15% of those under 25, the opposite of what I would expect (though I don’t know if this is a percentage of those who use the language, or includes those who do not know it at all).

Frameworks is another notable topic. Everyone loves Node.js; but two of the frameworks on offer are “.NET Core” and “ASP”. This is odd, since .NET Core is not really a framework, and ASP normally refers to the ancient “Active Server Pages” framework which nobody uses any longer, and ASP.NET runs on .NET Core so is not alternative to it.

This may be a clue that the HackerRank company or community is not well attuned to the Microsoft platform. That itself is of interest, but makes me question the validity of the survey results in that area.

QCon London 2017: IoT insecurity, serverless computing, predicting technical debt, and why .NET Core depends on a 36,000 line C++ file

I’m at the QCon event in London, a multi-vendor conference aimed primarily at enterprise developers and architects.

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Adam Tornhill speaks at QCon London 2017

A few notes on day one. Alasdair Allan gave a keynote on security and the internet of things; it was an entertaining and disturbing résumé of all that is wrong with the mad rush to connect everything to the internet though short on answers; our culture has to change so that organisations such as hotels, toy manufacturers, appliance vendors and even makers of medical equipment take security seriously but it is not clear how this will come about unless so many bad things happen that customers start to insist on it.

Michael Feathers spoke on strategic code deletion, part of a track on “Dark code: the legacy/tech debt dilemma.” This was an excellent session; code is added to projects more often than it is removed, and lack of hygiene in this regard has risks including security, reliability and performance. But discovering which code is safe to remove is not always trivial, and Feathers explored some of the nuances and suggested some techniques.

Steve Faulkner gave a session on serverless JavaScript, or more specifically, using Amazon Web Services (AWS) Lambda and API Gateway. Faulkner said that the API Gateway was the piece that made Lambda viable for them; he is Director of Platform Engineering at Bustle, a busy content site based in the USA. In a nutshell, moving from EC2 VMs to Lambda has yielded both financial savings and easier management. The only downside is performance; each call to a Lambda function takes a minimum of 100ms whereas the same function on a WM might take 20ms. In the end it is not critical as performance remains satisfactory.

Faulkner said that AWS is ahead of its competitors (Microsoft, Google and IBM were mentioned) but when pressed said that both Microsoft and Google offered strong alternatives. Microsoft’s Azure Functions are spoilt by the need to specify a maximum scale, rather than scaling automatically, but its routing solution is in some ways ahead of AWS, he said. Google’s Functions will be great when out of beta.

Adam Tornhill spoke on A Crystal Ball to prioritise Technical Debt, another session in the dark code track. This was my favourite of the day. Tornhill presented a relatively simple way to discover what code you should refactor now in order to avoid future issues. His method is based on looking for files with many lines of code (a way of measuring complexity) and many commits (suggesting high importance and activity), the “hotspots” in your projects. For more detail and some utilities see Tornhill’s blog.

Why do we end up with bad or risky code in our software? Tornhill said that developers often mistake organisational problems for technical problems and try unsuccessfully to fix them with tools.

He also mentioned an example of high-risk code, the file gc.cpp which performs garbage collection in .NET Core, the next generation of Microsoft’s .NET Framework. This file is over 36,000 lines and should be refactored. There is a discussion on the subject here. It exactly bears out Tornhill’s point. A developer proposes to refactor the file, back in March 2015. Microsoft’s Karel Zikmund defends the status quo:

Why it is this way? … Partly historical reasons (it is this way since the start). Partly because devs working on it didn’t feel the urge to refactor it. Partly because splitting of gc.cpp is non-trivial and risky and because it does not bring too big value (ramp up in the code base can be gained also in the combination of reading BOTR and debugging the code). Why it is staying this way? … Cost/benefit/risk ratio is IMO not in favor of a change here.

Few additional thoughts:
Am I happy that there is only 1 large file? No, but it doesn’t hurt me much either.
Do I see the disadvantages of large file? Yes, but I don’t think they are huge. More like minor annoyances with easy workarounds.
And to turn it around: Do you see the risk of any changes here? Do you see the cost of extra careful code reviews to mitigate the risk?

Strictly technically, we truly believe this is a formatting change. If it was simple to split it up and if it would be low risk and if it would be very easy to review, it might be worth the ‘minor’ improvements mentioned above … but I don’t see that combo happening (not on a noticeable scale in gc.cpp).
On a personal note: I also trust CLR team that if all these three things were true, the refactoring would have happened long time ago.

Note that some of this code goes back beyond .NET Core to the .NET Framework, the “historical reasons” that Zikmund mentions. We can see that the factors preventing change are as much organisational as technical.

Finally I attended a session on Microsoft’s Cognitive Services. Note this was in the “Sponsored solution track”. Microsoft also has a stand here focused on its Cognitive Services.

There is not much Microsoft Platform content at QCon and it seems under-represented, though many of the sessions are applicable to developers on any platform. I am not sure of all the reasons for this; there used to be an Advanced .NET track at QCon. It does reflect some overall development trends as well as the history and evolution of QCon itself. That said, there is a session on SQL Server on Linux so the company is not completely invisible here.

As for the session, it was a reasonable overview of Microsoft’s expanding Cognitive Services APIs, which covers things like image recognition, speech recognition and more. I would have liked more depth and would have preferred to hear from a practitioner, in other words, “we built an application on Cognitive Services and this is what we learned.” I am not altogether clear why the company is pushing this so hard, except that it is a driver for developers to use Azure. I asked about how developers should deal with the problem of uncertainty*, in other words, that Cognitive Services does not deliver absolute results but rather draws conclusions with a confidence score – eg it might be pretty sure that an image contains a human face, fairly sure that it is male, and somewhat confident that the age of the person is mid forties. When the speaker demoed speech recognition it went pretty well except that “Start” was transcribed as “Stop.” This stuff is difficult.

Looking forward now to Day Two: Containers, Machine Learning, and more.

*More concisely expressed as “Systems are moving from the deterministic to the probabilistic” by Stephen Whitworth, who is now speaking on Machine Learning.

Microsoft to release Visual Studio for the Mac – except it is not

Microsoft’s Mikayla Hutchinson (ex Xamarin) has announced Visual Studio for the Mac:

This is an exciting development, evolving the mobile-centric Xamarin Studio IDE into a true mobile-first, cloud-first development tool for .NET and C#, and bringing the Visual Studio development experience to the Mac.

I tend to agree that it is a significant piece of news. It signals Microsoft’s intent to offer first-class support for Mac developers. Other than at Microsoft events, the majority of the developers I see at conferences carry Macs rather than Windows laptops, and if the company is to have any hope of winning them over to its cross-platform ASP.NET web application framework, getting excellent development support on Macs is a critical step.

Naming things is not Microsoft’s greatest strength though. Sometimes it gives different things the same name, such as with OneDrive and OneDrive for Business, or Outlook for Windows and Outlook for iOS and Android. It makes sense from a marketing perspective, but it is also confusing.

This is another example. No, Microsoft has not ported Visual Studio to the Mac. This is a rebrand of Xamarin Studio, originally a cross-platform IDE for its C# mobile app framework, but more recently Mac-only.

Hutchinson makes the best of it:

Its UX is inspired by Visual Studio, yet designed to look and feel like a native citizen of macOS …. Below the surface, Visual Studio for Mac also has a lot in common with its siblings in the Visual Studio family. Its IntelliSense and refactoring use the Roslyn Compiler Platform; its project system and build engine use MSBuild; and its source editor supports TextMate bundles. It uses the same debugger engines for Xamarin and .NET Core apps, and the same designers for Xamarin.iOS and Xamarin.Android.

The common use of MSBuild is a key point. “Although it’s a new product and doesn’t support all of the Visual Studio project types, for those it does have in common it uses the same MSBuild solution and project format. If you have team members on macOS and Windows, or switch between the two OSes yourself, you can seamlessly share your projects across platforms,” says Hutchinson.

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The origins of what will now be Visual Studio for the Mac actually go back to the early days of the .NET Framework. Developer Mike Kruger decided to write an IDE in C# in order to work more easily with a pre-release of .NET Framework 1.0. His IDE was called SharpDevelop. Here is an early version, from 2001:

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Of course by then most developers used Visual Studio to work with C#, but there were several reasons why SharpDevelop continued to have a following. Unlike Visual Studio, it was built in C# and you could get all the code. It was free. It was also of interest to Mono users, Mono being the open source implementation of the .NET Framework originated by Miguel de Icaza (also now at Microsoft). In 2003, Mono developers started work on porting SharpDevelop to run on Linux using the GNOME toolkit (Gtk#). This forked project became MonoDevelop.

Xamarin (the framework) of course has its roots in Mono and when Xamarin (the company) decided to create its own IDE it based it on MonoDevelop. So MonoDevelop evolved into Xamarin Studio.

Incidentally, SharpDevelop is still available and you can get it here.  MonoDevelop is still available and you can get it here.

So now some sort of circle is complete and what began as SharpDevelop, a rebel imitation of Visual Studio, will now be an official Microsoft product called Visual Studio for the Mac – though how much SharpDevelop code remains (if any) is another matter.

Historical digression aside, the differences between Visual Studio and Visual Studio for the Mac are not the only point of confusion. There is also Visual Studio Code, an editor with some IDE features, which is cross-platform on Windows, Mac and Linux. This one is based on the Google-sponsored Chromium project and has won quite a few friends.

Should Mac users now use Visual Studio Code, or Visual Studio for the Mac, for their .NET Core or ASP.NET Core development? Microsoft will say “your choice” but it is a good question. The key here is which project will now get more attention from both Microsoft and other open source contributors.

Still, we should not complain. Two rival Microsoft IDEs for the Mac are a considerable advance on none, which was the answer until Visual Studio Code went into preview in April 2015.

StackOverflow developer survey shows decline in C#, Windows

StackOverflow, a popular (and the best) site for programming queries, has published its annual developer survey. Respondents included:

26,086 people from 157 countries participated in our 45-question survey. 6,800 identified as full-stack developers, 1,900 as mobile developers, 1,200 as front-end developers, 2 as farmers, and 12,000 as something else.

That is a decent sample size, though not necessarily representative of the entire developer community.

What is notable? Here are a few things that stood out for me:

Developers are young. The largest group is 25-29 and the average age 28.9 years old.

92.1% of respondents are male. Ouch.

Software is still a good bet for a career even if you have no qualifications. 41.8% declared themselves self-taught. That said, it is not clear to me what proportion of respondents do programming as their main job. Presumably not the two farmers?

If you look at the “Most popular technologies”, there is a striking decline in C# over the last three years:

2013: 44.7%

2014: 37.6%

2015: 31.6%

That’s a shame because C# is an excellent language. The reason? It’s speculation, but probably means less Windows development, whether server or desktop.

Swift is top of the “most loved” list, meaning a language that developers intend to continue with. Salesforce tops the “most dreaded”, meaning a platform that developers cannot wait to abandon, followed by Visual Basic.

What OS do developers use on the desktop? Here, Windows remains the biggest, but is declining:

2013: 60.4%

2014: 57.9%

2015: 54.5%

Windows XP has declined dramatically, down from 10.8% in 2013 to 1.0% today.

Where have developers gone, if they no longer use Windows? Mac is up over the period, but only by 2.8% share. 3.5% are using “Other”, interesting (Chromebook?).

I’ll stop there; I don’t want to spoil the survey.

Conclusions? This puts some data (albeit imperfect) on the theory that Microsoft is losing its grip on the developer community – though note that Microsoft’s technology in general remains popular, just less so than before.

Postscript: Several on Twitter have observed that most languages have declined over the period, not just C#. Here’s the difference in share from 2013 to 2015 for some of them:

JavaScript: –2.2%

SQL: –11.6%

Java: –5.1%

C#: –13.1%

PHP: –5.1%

In other words, all of the top 5 have declined, though C# has declined the most.

What does this mean? Since the numbers sum to more than 100%, it might imply more specialisation. Or it might just say something about how the StackOverflow community has evolved, since that is the source of the data. Still, it seems to me that you cannot spin this as good news for Microsoft, though it might be less bad than it first appears.

Writing for The Register

Since the beginning of October I have been working two days a week for The Register. I am still freelance for the other three days so also available for other work.

Why the Register? I have been contributing for some years and there are several things I like about the publication. It is known of course for its attention-grabbing headlines but you will also find solid technical content there; it was one of the first sites to report the Linux Shellshock bug, for example, and did so in detail with strong follow-up posts, making the site a good one for admins to follow. There is also a strong developer readership which is good from my perspective. Editorially it is diverse and you will find plenty of different opinions expressed by the staff and contributors, which I consider a strength. Organisationally, The Register is refreshingly unbureaucratic. 

It reminds me in some ways of the best days of Personal Computer World, a famous print magazine which ceased publication in 2009. PCW was a delight because it was not shy about covering small niches as well as mainstream technology, in the days when it had plenty of editorial pages to fill.

The comments are worth reading too; not all of them, but there are plenty of smart readers. On any specific topic, logic suggests that some of the readers will know more about it than the journalist; you should always glance at the comments.

The Register is also a well-read site; number 513 in the UK according to Alexa, and 2204 in the USA. Judging by Alexa it is seems to be the most popular tech news site in the UK though I am not an expert on web stats.

I will continue to post here of course, as well as covering hardware, gadgets and audio on http://gadgets.itwriting.com/.

In case you missed it, this is what I came up with in October – it was a bit more than 2 days a week as it turned out, I am not superhuman:

Programming Office 365- Hands On with Microsoft’s new APIs

Microsoft unwraps new auto data-protection in Office 365 tools

Mozilla- Spidermonkey ATE Apple’s JavaScriptCore, THRASHED Google V8

Microsoft shows off spanking Win 10 PCs, compute-tastic Azure

Happy 2nd birthday, Windows 8 and Surface- Anatomy of a disaster

Entity Framework goes ‘code first’ as Microsoft pulls visual design tool

Lollipop unwrapped- Chromium WebView will update via Google Play

Microsoft and Dell’s cloud in a box- Instant Azure for the data centre

Migrate to the cloud and watch your business take flight

Docker’s app containers are coming to Windows Server, says Microsoft

Sway- Microsoft’s new Office app doesn’t have an Undo function

Influential scribe Charles Petzold- How I figured out the Windows API

Software gurus- Only developers can defeat mass surveillance

Xamarin, IBM lob cross-platform mobile app dev tools at Microsoft coders

Windows 10 feedback- ‘Microsoft, please do a deal with Google to use its browser’

No tiles, no NAP – next Windows for data centre looks promising

Vanished blog posts- Enterprise gaps- Welcome to Windows 10

One Windows- How does that work… and WTF is a Universal App-

Windows 10- One for the suits, right Microsoft- Or so one THOUGHT

Testing mobile apps: Xamarin goes live with Test Cloud for iOS and Android (but no Windows Phone)

Testing a mobile app is challenging, thanks to operating system fragmentation combined with diversity of hardware. In April 2013 Xamarin acquired a company called LessPainful, specialists in functional testing for mobile apps, which had created a mobile app testing tool called Calabash. Calabash is based on Cucumber, and lets you define test steps and then combine them into natural language tests. LessPainful also had a cloud testing service which let you run tests on remote physical devices and see visual test reports.

Eighteen months on, Xamarin has now gone live with Test Cloud, and has announced some big names which it says are using the service, including Dropbox, Flipboard and eBay.

There are currently 1036 devices (the number changes regularly) in the Test Cloud, including 273 iOS and 763 Android (Windows Phone is not supported, but Amazon’s Fire Phone and Kindle Fire does appear in the list).

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You write your tests either in Calabash or in C#, upload your app and the tests to Test Cloud, wait a while, and then get notification that the tests are done and a report ready to view.

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You can simulate events such as changes in location, device rotation, network dropouts, and of course user interactions like taps and gestures. You get screenshots and performance data (memory and CPU usage) for each test step.

You can also integrate with CI (Continuous Integration) systems like TFS, Jenkins and TeamCity to automate testing.

Writing and maintaining tests is hard work, of course, but for businesses that can afford the investment in both time and money, Test Cloud is likely to be a great improvement on manually gathering up as many devices as you can find and installing your app on all of them.

The cost is significant though, starting at $1000 per month for up to 2 apps and 200 device hours. You have to pay annually too, so it looks like a strategy of just buying one month towards the end of your development cycle will not work.

That said, I have been told that Xamarin will be coming out with an Indie version in the future that has a lower price.

Brief reflections on 50 years of BASIC

Beginner’s All-Purpose Symbolic Code (BASIC) has turned fifty, as reported on The Reg and by Jack Schofield on ZDNet. A great moment in computer history, or would we have been better off without it?

My first computer (a Commodore PET) ran Basic from ROM, and without it you could do nothing, though developers bypassed it by using the POKE command to write low-level instructions into memory. The language is meant to be forgiving (as far as a computer language can be) and English-like, at the expense of being a little more verbose. It is case-insensitive and does not require braces or semi-colons to indicate blocks or lines of code, which makes programming look less intimidating for beginners.

I graduated onto an Atari ST, for which there was an excellent Basic implementation called GFA Basic, fast and capable. This was great for writing utilities, though, though serious programming tended to use one of several strong C compilers: Lattice C, Mark Williams C, HiSoft C come to mind.

Basic also had a role, even on the ST, as a macro language for applications. For example, the Superbase database manager used a version of Basic.

The company most strongly associated with Basic though is Microsoft. A version of Basic came with MS-DOS.

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Microsoft also supported Basic for professional development. Microsoft Basic Professional Development System 7.x was a well-regarded development tool for business applications, though commercial shrink-wrap software tended to be written in C or C++.

That trend followed through to the Windows graphical environment. Visual Basic (VB), which made it easy to code Windows applications, was perhaps the most significant Basic release in terms of its impact, especially when it reached version 3.0 with full database support. Its popularity was such that many developers felt wounded when Microsoft discontinued Visual Basic 6.0, a direct successor, in favour of Visual Basic .NET which is something incompatible and different.

Further, VB 6.0 or something very like it lives on today, in the form of Visual Basic for Applications as found in all recent versions of Microsoft Office.

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Despite this, Basic is in decline. Most of the professional developers I meet at events like Build use C# in preference to Visual Basic, there being little reason not to. C# is the premier language of .NET, and Visual Basic gets in the way if you want to keep up with latest .NET developments. Xamarin, which lets you code in .NET for iOS and Android, supports C# but not Visual Basic. Once you come to terms with semi-colons, braces and case-sensitivity, there is no real advantage to Visual Basic and C# is no more difficult.

I do see Visual Basic still used in education though, as well as by some developers who either prefer the language or are so used to it that they see no need to change; and to be fair, Xamarin aside, there is little if anything you can do in C# that you cannot also do in VB and the output is more or less the same.

The Roslyn project, which will be part of the next version of C# and probably in the next release of Visual Studio, lets you paste C# code as VB and vice versa.

Nevertheless, I believe we will see further decline in Basic usage, especially as it is little used outside Microsoft’s platform.

Would it have been better if Microsoft has not adopted Basic so wholeheartedly? There are some problems with Basic, though it is possible to write excellent code in Basic just as you can write poor code in C#, Python, C, or other more fashionable languages. Some issues:

  • Early versions of Basic encouraged badly structured programming with keywords like GOTO and GOSUB resulting in intricate loops that were hard to follow or debug.
  • Basic abstracts how software works to such an extent that you do not learn some important programming concepts such as pointers, addresses, memory allocation.
  • There is no natural progression from Basic to the C-like languages which dominate computing (C,C++,JavaScript,C#).
  • Visual Basic encourages developers to mix GUI code and business logic in the same files, as well as building user interfaces that tend not to scale well.
  • Small and declining professional use means that Basic is less useful than many other languages in the job market.

That said, Basic powers many excellent business applications as well as introducing many to the wonders of programming, and deserves our respect.

Notes on styling a Windows Store app ListView to vary item appearance according to the data

Problem: You have a ListView containing data. You want to vary the appearance of items in the ListView according to the value of the data.

I spent some time on this in relation to a panel for a game I am writing. For example, you have a ListView containing numbers. How can you have negative numbers appear in red?

image

In desktop WPF (Windows Presentation Foundation) you could do this with Property Triggers but these are not supported in Store apps.

One way to do this is with a value converter. Add a class to your project called MyValueConverter. Make the class public, and inherit from Windows.UI.Xaml.Data.IValueConverter.

Right-click IValueConverter and choose Implement Interface to have Visual Studio create two stub methods, Convert and ConvertBack.

This class is going to return an object which will be applied to the Foreground property of a ListViewItem. The Convert method looks like this:

public object Convert(object value, Type targetType, object parameter, string language)

At runtime, the value argument will contain the item displayed in this row of the ListView. The targetType will match the type of the property we are setting, which in this case is a Brush object.

Now add an instance of MyValueConverter to MainPage.xaml (or App.xaml) as a resource. If there is no Page.Resources element, create it, and add an instance of MyValueConverter with the Key “NumberForegroundConverter”:

<Page.Resources>
<local:MyValueConverter x:Key="NumberForegroundConverter" />
</Page.Resources>

Next, select the ListView element in the XAML editor or designer. Right-click the selected element in the designer, and choose Edit Additional Templates – Edit Generated Item Container (ItemContainerStyle) – Edit a Copy …

image

Accept the default name of ListViewItemStyle1 and click OK.

This generates an element that defines the layout and appearance of items in the ListView. Currently it does not appear to do anything, since it is a copy of the default settings.

Find the element called <ListViewItemPresenter> which is nested within <ControlTemplate TargetType=”ListViewItem”>. No Foreground attribute for ListViewItemPresenter is generated, but we can add one:

Foreground="{Binding Converter={StaticResource NumberForegroundConverter}}"

If you now run the project, you will get an exception, because the methods in MyValueConverter do not yet have any code. Now we have to think about the type of the items in the ListView. In this example, I just typed some strings into the XML editor:

<ListView ItemContainerStyle="{StaticResource ListViewItemStyle1}">
<x:String>145</x:String>
<x:String>-30</x:String>
<x:String>442</x:String>
</ListView>

All the items are strings, so the Convert method can look like this:

String s = (String)value; //note this ONLY works if the item is always a string

if (float.Parse(s) < 0)
{
return new SolidColorBrush(Windows.UI.Colors.Red);
}
else
{
return new SolidColorBrush(Windows.UI.Colors.White);
}

We don’t care about the ConvertBack method so can use this code:

return Windows.UI.Xaml.DependencyProperty.UnsetValue;

It works but there are some issues. One oddity is that when you roll the mouse over a negative number, it looks the same as a positive number.

image

This is because we did a converter for the Foreground property but not for the SelectedForeground property. XAML in Store apps makes extensive use of themes, and themes include a lot of brushes.

Another issue, which may or may not impact your application, is that the converter code does not run again if you change the displayed item dynamically. That is, if you replace the item it updates OK, but if you update the existing item it does not.

A slightly more complex example will demonstrate this. Let’s say that rather than displaying strings, the ListView is displaying Widget quantities, where a negative number indicates backorders. The ListView is bound to an ObservableCollection<Widget>, and the Widget class implements INotifyPropertyChanged so that the ListView will update automatically when a Widget property changes. Note that the NumberForegroundConverter must be updated to accept a Widget value rather than a string.

Here is what happens if a Widget had a negative quantity when the ListView was first populated, but got dynamically updated to a positive value (some stock arrived):

image

Oops! Now the positive quantity is in red.

We can fix this by abandoning the converter, and instead giving the Widget class a Foreground property of its own, calculated to return Red for negative quantities and White for positive. Make sure it fires a NotifyPropertyChanged event when updated. Now the Foreground property in <ListViewItemPresenter> looks like this:

Foreground="{Binding Foreground}"

It works:

image

I used this approach in my game in order to implement an Enabled property that indicates items which are unselectable. This changes dynamically according to the state of the play.

Note that you are unlikely to want a Foreground property in your business objects, but could create a DisplayWidget class for the purpose.

I realise that these are not the only ways to create a ListView which styles items differently according to their values, but they may be the simplest. Other suggestions and comments are welcome.

Update: Mike Taulty has some comments and suggestions here.