The Social Transf#ormation of Software Development

This post is part of the F# Advent Calendar in English 2017 project. Check out all the other great posts there! And special thanks to Sergey Tihon for organizing this. (Also, thanks to Scott W from whom I copy/pasted the prior sentences.)

Since we are in the holiday season, it is appropriate that I spend some time reflecting on how awesome the FSharp language is. Also during this season, as we turn into a new year, it makes sense to look a bit into the future. Full disclaimer – I have no idea what I am talking about.

When I was an undergraduate, my advisor recommended The Social Transformation of American Medicine by Paul Starr. The book centers on American physicians and how they used social factors to achieve the professional autonomy and financial rewards that they have today. Indeed, there are few other professions that have such a powerful “moat” around their profession. I still remember a line that Starr used when describing how the AMA used the rule of law to crush non-certified physicians at the turn of the twentieth century: “Power abhors competition like nature abhors a vacuum” *

I recently re-read much of the book, spurred on by Uncle Bob Martin’s talk about professional autonomy that I saw at Skills Matter a couple of years ago (similar one here) . I am wondering how our professional will shake out – computer programmers are indispensable, in fact they are one of the few competitive advantages for companies*. Like it or not, all companies are software shops, the ones with good management get this and are adapting, the bad ones… well, they can always merge. Yet the average software engineer does not have the kind of compensation and autonomy that the average physician has. To be sure, there are some “rock stars”, but the averages do not compare.

So why don’t software engineers have such status? One can make an argument that correct software can be just as life-saving as a physician’s diagnosis, and potentially at a larger scale. So if it is not societal importance, what is it? Starr’s books has some interesting observations that lend itself to some interesting questions which would certainly increase the software developer’s status.

· Does the software industry need to have established practices that at enforced by the rule of law?

· Does anyone deploying software need to be licensed? There might be some minor logistical issues, but certainly doable (just tell VC it is a Blockchain use case)

· Does anyone writing software need to join an overall unified professional organization?

· Do we socialize politicians that “kids learn to code” is a dumb idea just like “kids learn to do surgery”?

· Do we educate business leaders of non-tech shops that the problem is not enough programmers but too many bad programmer? If they want better results, pay more and implement steps #1-#3 above. Does it then raise the possibility that their many management teams and associated skill set are pretty much irrelevant in a 21st century technology company?

· Does the industry tell computer programmers that can’t pass the muster for the 1st three bullet points that they need to find a different profession?

Which leads us to FSharp. FSharp is an awesome language that had a hard landing on the enterprise space. As our profession evolves, the market will have less influence. As far as I can see, the entire package of Windows, Visual Studio, .NET, C#, Desktop App, and Web Forms is coming to an end. Will newer languages like F# will get a serious look? I will be interested to see if the same regulatory forces that will lead to the end of the Mort will also pick and choose winning languages. God help us if they decide on javascript.

So what can we do in the FSharp community? Starr has some interesting lessons here too:

· Stick to our guns and continue to push for high-quality teams and code. Like physicians that turned away patients that would not follow their orders, avoid shops that treat development as a cost of business versus a strategic asset

· If you do work at a place like that, be an outspoken advocate for change.

· Get involved with startups and non-enterprise technical communities.

· Get involved with government – volunteer on boards, get to know your local politicians, spend some time raising FSharp awareness to key stakeholders

· Code Code Code. Keep your coding chops sharp.

In any event, I don’t know the answers to the above questions.  I don’t even know if they are the right questions.  To be sure, I maintain our profession is evolving and we do have some control of where it will end up.  With that in mind, hopefully the FSharp community can continue to be a force of positive change in our industry.

Onward to 2018!

 

** I find this line very useful in a variety of settings -> esp. in explaining American politics to friends from overseas

** IT does matter. It always has. The article was wrong from the moment it was published.

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Age and Sex Analysis Of Microsoft USA MVPs

A couple of weeks ago, this came across my Twitter

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I participated in this hackathon (well, helped run the F# one).  My response was:

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I was surprised that I got into this exchange with a Microsoft PM:

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That last comment by me was inspired by Mark Twain: “never wrestle with a pig.  You just get dirty and the pig likes it.”  But it did get me to thinking about the composition of the US MVPs.  I did an analysis a couple of years ago of the photos of the Microsoft MVPs (found here and here) so it made sense to follow up on that code and see if I was wrong about my “middle age white guy” hypothesis.  I could get the photos from the MVP site and pass them into the Microsoft Cognitive Services API for facial analysis for age/sex data.  Using F# made the analysis a snap.

A nice thing about the Microsoft MVP website is that it is public and has photos of the MVPs.  Here is one of the pages:

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and when you look at the source of the page, each of those photos has a distinct uri:

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I opened up Visual Studio and created a new F# project.  I went into the script file and brought in the libraries to do some http requests.  I then created a couple of functions to pull down the HTML of each of the 19 pages and put it into 1 big string:

1 let getPageContents(pageNumber:int) = 2 let uri = new Uri("http://mvp.microsoft.com/en-us/search-mvp.aspx?lo=United+States&sl=0&browse=False&sc=s&ps=36&pn=" + pageNumber.ToString()) 3 let request = WebRequest.Create(uri) 4 request.Method <- "GET" 5 let response = request.GetResponse() 6 use stream = response.GetResponseStream() 7 use reader = new StreamReader(stream) 8 reader.ReadToEnd() 9 10 let contents = 11 [|1..19|] 12 |> Array.map(fun i -> getPageContents i) 13 |> Seq.reduce(fun x y -> x + y)

(OT: Since I did a map..reduce on lines 12 and 13, does that mean I am working with “Big Data”?)

I then created a quick parser to find only the uris of the photos in all of the HTML.

1 let getUrisFromPageContents(pageContents:string) = 2 let pattern = "/PublicProfile/Photo/\d+" 3 let matchCollection = Regex.Matches(pageContents, pattern) 4 matchCollection 5 |> Seq.cast 6 |> Seq.map(fun (m:Match) -> m.Value) 7 |> Seq.map(fun v -> "https://mvp.microsoft.com/en-us" + v + "?language=en-us") 8 |> Seq.toArray 9 10 let uris = getUrisFromPageContents contents

Sure enough, I got 684 uris for MVP photos.  I then wrote another Web Request to pull down each of the photos and save them to disk:

1 let saveImage uri = 2 use client = new WebClient() 3 let id = Guid.NewGuid() 4 let path = @"F:\Git\ChickenSoftware.ParseMvpPages.Solution\ChickenSoftware.ParseMvpPages\photos\" + id.ToString() + ".jpg" 5 client.DownloadFile(Uri(uri),path) 6 7 uris 8 |> Seq.iter saveImage 9

And I now have all 684 photos on disk.

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I did not bring down the names of the MVPs – instead using a GUID to randomize the photos, but a name analysis would also be interesting.  With the photos now local, I could then upload them to Microsoft Cognitive Services API to do facial analysis.  You can read about the details of the API here.  I created a third web request to pass the photo up and get the results from the API:

1 let getOxfordResults path = 2 let queryString = HttpUtility.ParseQueryString(String.Empty) 3 queryString.Add("returnFaceId","true") 4 queryString.Add("returnFaceLandmarks","false") 5 queryString.Add("returnFaceAttributes","age,gender") 6 let uri = "https://api.projectoxford.ai/face/v1.0/detect?" + queryString.ToString() 7 let bytes = File.ReadAllBytes(path) 8 let client = new HttpClient() 9 client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key","xxxxxxxxxxx") 10 let response = new HttpResponseMessage() 11 let content = new ByteArrayContent(bytes) 12 content.Headers.ContentType <- MediaTypeHeaderValue("application/octet-stream") 13 let result = client.PostAsync(uri,content).Result 14 Thread.Sleep(TimeSpan.FromSeconds(5.0)) 15 match result.StatusCode with 16 | HttpStatusCode.OK -> Some (result.Content.ReadAsStringAsync().Result) 17 | _ -> None

Notice that I put a 5 second sleep into the call.  This is because Microsoft throttles the requests to 20 per minute. Also, since some of the photos do not have a face, I used the F# option type. The results come back from the Microsoft Cognitive Services API  as Json. To parse the results, I used the FSharp Json Type Provider:

1 type FaceInfo = JsonProvider<Sample="[{\"faceId\":\"83045097-daa1-4f1c-8669-ed012e9b5975\",\"faceRectangle\":{\"top\":187,\"left\":209,\"width\":214,\"height\":214},\"faceAttributes\":{\"gender\":\"male\",\"age\":42.8}}]"> 2 3 let parseOxfordResuls results = 4 match results with 5 | Some r -> 6 let face = FaceInfo.Parse(r) 7 match Seq.length face with 8 | 0 -> None 9 | _ -> let header = face |> Seq.head 10 Some(header.FaceAttributes.Age,header.FaceAttributes.Gender) 11 | None -> None

So now I can get estimated age and gender from Microsoft Cognitive Services API.  I was disappointed that the API does not estimate race.  I assume they have the technology but from a social-acceptance point of view, they don’t make it publically available.  In any event, a look though their photos show that a majority are white people.  In any event, I went ahead and ran this and went out to work on my sons stock car while the requests were spinning.

1 #time 2 let results = 3 let path = @"F:\Git\ChickenSoftware.ParseMvpPages.Solution\ChickenSoftware.ParseMvpPages\photos" 4 Directory.GetFiles(path) 5 |> Array.map(fun f -> getOxfordResults f) 6 |> Array.map(fun r -> parseOxfordResuls r)

When I came back, I had a nice sequence of a tuple that contained ages and genders.

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To analyze the data, I pulled in Math .NET.  First, I took a look age:

1 Seq.length results //684 2 3 let ages = 4 results 5 |> Seq.filter(fun r -> r.IsSome) 6 |> Seq.map(fun o -> fst o.Value) 7 |> Seq.map(fun a -> float a) 8 9 let stats = new DescriptiveStatistics(ages) 10 let count = stats.Count 11 let largest = stats.Maximum 12 let smallest = stats.Minimum 13 let mean = stats.Mean 14 let median = Statistics.Median(ages) 15 let variance = stats.Variance 16 let standardDeviation = stats.StandardDeviation 17 let kurtosis = stats.Kurtosis 18 let skewness = stats.Skewness 19 let lowerQuartile = Statistics.LowerQuartile(ages) 20 let uppserQuartile = Statistics.UpperQuartile(ages) 21

Here are the results. 

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I got 620 valid photos of the 684 MVPs – so a 91% hit rate and I have enough observations to make the analysis statistically valid.  It looks like Cognitive Services made at least 1 mistake with an age of 4.9 years –> perhaps someone was using a meme for their photo?  In any event, the mean is estimated at 41.95 and the median is 40.95, so a slight skew left. (Note I mislabeled it on the screen shot above)

I then wanted to see the distribution of the ages so I brought in FSharp charting and ran a basic histogram:

1 open FSharp.Charting 2 3 let chart = Chart.Histogram(ages,Intervals=10.0) 4 Chart.Show(chart)

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So the ages look very Gaussian.

I then decided to look at gender:

1 let gender = 2 results 3 |> Seq.filter(fun r -> r.IsSome) 4 |> Seq.map(fun o -> snd o.Value) 5 6 gender 7 |> Seq.countBy(fun v -> v) 8 |> Seq.map(fun (g,c) -> g, c, float c/float count)

With the results being:

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So there are 12% females and 88% males.  With an average age 42 years old and 88% male, “middle age white guy” seems like an appropriate label and I stand by my original tweet – we certainly have work to do in 2017.

You can find the gist here

Creating Dynamic Uris For Visual Studio Web Tests

This post is part of the F# Advent Calendar in English 2015 project. Check out all the other great posts there! And special thanks to Sergey Tihon for organizing this. (Also, thanks to Scott W from whom I copy/pasted the prior sentences.)

One of the cooler features built into Visual Studio 2015 is the ability to create web tests and load tests. I had blogged about customizing them here and here but those posts did not cover the scenario where I need to dynamically create a uri. For example, consider the following web test that is hitting a web api 2 controller with some very rpc syntax:

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Notice that the ContextParameters are setting the uri so I can move the test among environments.  Also, notice the dynamic part of the uri called {{friendlyName}}.

One of the limitations of the out of the box web test is that context parameters cannot be data bound but can be appended as part of the uri. Also, query string parameters can be data bound cannot be appended as part of the uri. So if we want to go to a database and get a series of friendly names for our chickens to pass into our test, we are stuck.  Grounded really.

Enter web test plug ins.  I added a F# project to the solution and added a .fs file called UriAdjuster like so:

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I then added references to:

Microsoft.VisualStudio.QualityTools.WebTestFramework and FSharp.Data.TypeProviders

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I then added the following code to the UriAdjuster file:

namespace ChickenSoftware.ChickenApi.LoadTests.PlugIns open System open System.Text open Microsoft.FSharp.Data.TypeProviders open Microsoft.VisualStudio.TestTools.WebTesting type internal EntityConnection = SqlEntityConnection<"myConnectionString",Pluralize = true> type public UriAdjuster() = inherit WebTestPlugin() let context = EntityConnection.GetDataContext() override this.PreRequestDataBinding(sender:Object, e:PreRequestDataBindingEventArgs) = let random = new Random() let index = random.Next((context.Chickens |> Seq.length) - 1) let chicken = context.Chickens |> Seq.nth(index) e.Request.Url <- e.Request.Url.Replace("{{friendlyName}}",chicken.FriendlyName) base.PreRequestDataBinding(sender,e) ()

So I am going to the database on every request (using the awesome of type providers), pulling out a random chicken and updating the url with its friendlyName.

So that’s it.  We now have the ability to create valid uris that we can then dump into our load test.  Since our load test is running so fast, I guess we can say it is flying. So perhaps chickens can fly?

Happy holidays everyone.

Taking a Hiatus From Blogging

I have blogged every Tuesday for the last six years.  Thank you to all of the people who took the time to read my posts and give comments.  I hope you benefitted from the content (if not the rookie formatting and sometimes creative spelling/grammar).  Recently, I signed a deal with  a publisher to write a book that has a a pretty aggressive deadline.  Because of the time commitment that writing a book takes,  I am taking a hiatus from blogging.  If all goes to plan, I will resume blogging in mid-2016.

 

Using Mocking Frameworks To Help With Unit Testing UI Controls

One of the more common reasons that developers tell us of why they don’t unit test is “All of my application is visual controls with code behind. Refactoring all of that code to a .dll that can be united tested will take more time than it is worth.” While it is true that unit testing is easier if your application lives “in code” as a separate assembly, you can still use unit testing in a UI-heavy code base. By judiciously using a mocking framework, you can speed up the process even more.

Consider this form from a WinForm application written in VB.NET.

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The grid view has the following code behind :

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click For counter = 0 To DataGridView1.RowCount - 1 If (DataGridView1.Rows(counter).Cells(11).FormattedValue) Then If (DataGridView1.Rows(counter).Cells(10).Value <> "") Then TextBox1.Text = FormatCurrency(TextBox1.Text - DataGridView1.Rows(counter).Cells(10).Value, 2) End If End If Next End Sub

 

The business logic is intermingled with the visual controls (TextBox1, DataGridView1, etc…). Is there a way to easily unit test this code? The answer is yes. Step one is to add a unit test project to the solution. Step two is to break the sub method into a function method. Once the methods have an input and an output, you can put a unit test on it. For example:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click For counter = 0 To DataGridView1.RowCount - 1 Dim initialValue = TextBox1.Text Dim cell0 = DataGridView1.Rows(counter).Cells(11) Dim cell1 = DataGridView1.Rows(counter).Cells(10) TextBox1.Text = GetCalculatedValue(initialValue, cell0, cell1) Next End Sub Public Function GetCalculatedValue(initalValue As String, cell0 As DataGridViewCell, cell1 As DataGridViewCell) As String Dim returnValue As String = initalValue If (cell0.FormattedValue) Then If (cell1.Value <> "") Then initalValue = FormatCurrency(TextBox1.Text - cell1.Value, 2) End If End If Return initalValue End Function

And we can add a unit test like this:

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[TestMethod] public void GetCalculatedValue_ReturnsExpected() { Form1 instance = new Form1(); String baseValue = "$10.00"; DataGridView gridView = new DataGridView(); gridView.Columns.Add("TEST1", "TEST1"); gridView.Columns.Add("TEST2", "TEST2"); gridView.Rows.Add(new DataGridViewRow()); gridView.Rows[0].Cells[0].Value = "$1.00"; gridView.Rows[0].Cells[1].Value = "$2.00"; DataGridViewCell cell0 = gridView.Rows[0].Cells[0]; DataGridViewCell cell1 = gridView.Rows[0].Cells[1]; var actual = instance.GetCalculatedValue(baseValue, cell0, cell1); var expected = "$8.00"; Assert.AreEqual(expected, actual); }

 

Although this test runs green, it is suboptimal because we have to standup lots of objects (DataGridView, Columns, DataGridRow) just to get to the class we are interested in, in this case DataGridViewCell. Instead of generating all of that superfluous code, there is a better way to set the state of only the class we want – enter Mocking frameworks. Mocking frameworks give us the ability to focus only on the subjects under test (SUT) while ignoring everything else.

But there is a catch. There are 2 types of mocking frameworks: ones that generate their code based on inspecting the types and ones that generate their code based on the compiled IL. The former group includes RhinoMocks and Moq . If you try and add Moq to this unit test project and generate a DataGridViewCell like this:

[TestMethod] public void GetCalculatedValue_ReturnsExpected() { Form1 instance = new Form1(); String baseValue = "$10.00"; var mock0 = new Mock<DataGridViewCell>(); mock0.SetupGet(dataGridViewCell => dataGridViewCell.Value).Returns("$1.00"); var mock1 = new Mock<DataGridViewCell>(); mock1.SetupGet(dataGridViewCell => dataGridViewCell.Value).Returns("$2.00"); var actual = instance.GetCalculatedValue(baseValue, mock0.Object, mock1.Object); var expected = "$8.00"; Assert.AreEqual(expected, actual); }

You will get an exception

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Since we don’t control DataGridViewCell’s code, there is no way to change those properties to overidable/nonvirtual. As a general rule, you only use RhinoMocks/Moq on classes that you can control.

The other type of mocking framework (based on IL) can solve this problem. There are 2 commercial frameworks (JustMock, TypeMock) but they cost $399/year (as of this writing). There is a 3rd framework we can use and it is built into Visual Studio 2012+. It is called the Microsoft Fakes Framework. By adding this to your test project,

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you can craft your unit test like so:

[TestMethod] public void GetCalculatedValue_ReturnsExpected() { Form1 instance = new Form1(); String baseValue = "$10.00"; using (ShimsContext.Create()) { var cell0 = new ShimDataGridViewCell(new StubDataGridViewCell()); cell0.FormattedValueGet = () => { return "$1.00"; }; var cell1 = new ShimDataGridViewCell(new StubDataGridViewCell()); cell1.ValueGet = () => { return "$2.00"; }; var actual = instance.GetCalculatedValue(baseValue, cell0, cell1); var expected = "$8.00"; Assert.AreEqual(expected, actual); } }

and get green. The downside of using Microsoft Fakes is that you need to re-generate the fakes if the code changes. This makes it ideal for faking external libraries that don’t change much (like ADO.NET) but not assemblies that are under active development.

EjectABed Version 2 – Now Using the Raspberry Pi (Part 2)

With the connection from Twitter to the PI working well, I decided to hook up the bed top the PI.  The Bed is controlled via a server attached to a bellow that forces air to the screw drive.  You can read about how we figured that one out here.
My initial thought was that it would be easy as the Netduino implementation to control the servo was all of 5 lines of code.  The Netduino has built-in PWM ports and the api has a PWM class:
1 uint period = 20000; 2 uint duration = SERVO_NEUTRAL; 3 _servo = new PWM(PWMChannels.PWM_PIN_D5, period, duration, PWM.ScaleFactor.Microseconds, false); 4 _servo.Start(); 5 _servoReady = true;

However, when I went to look for a PWM port, there wasn’t one!  Ugh!  I want over to Stack Overflow to confirm with this question and sure enough, no PWM.  The only example for servo control that the Windows 10 code samples have are using the GPIO to activate a servo forwards and backwards, but that will not work because I need to hold the bellow in a specific place for the air to push correctly.  The Windows IoT team suggested that I use the AdaFruit PWM shield for the control

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So I ordered a couple and then my son soldered the pins in

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I then hooked up the shield to the servo and the PI
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and went to look for some PI code to control the pwms.  Another problem, there isn’t any!  I went over to the Raspberry Pi forums and it turns out, they are waiting for MSFT to finish that piece.  Ugh, I decided to take the path of least resistance and I removed that PWM shield and added back in the Netduino

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Now I have the ability to control the servo from the PI.  I would have rather cut out the Netduino completely, but the limitations of Win10 on Raspberry Pi won’t allow me to do that.  Oh well, it is still a good entry and it was a lot of fun to work on.

EjectABed Version 2 – Now Using the Raspberry Pi (Part 1)

I recently entered a hackster.io competition that centered around using Windows 10 on the Raspberry Pi.  I entered the ejectabed and it was accepted to the semi-final round.  My thought was to take the existing ejectabed controller from a Netduino and move it to a Raspberry Pi.  While doing that, I could open the ejectabed from my local area network to the internet so anyone could eject Sloan.
My 1st step was hook my Raspberry Pi up to my home network and deploy from Visual Studio to it.  Turns out, it was pretty straightforward.
I took a old Asus Portable Wireless Router and plugged it into my home workstation.  I then configured the router to act as an Access Point so that it would pass though all traffic from the router to which my developer workstation is attached.  I then attached the router to the PI and powered it though the PI’s USB port.  I then plugged the PI’s HDMI out to a spare monitor of mine.

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With all of the hardware plugged in, I headed over to Windows On Devices and followed the instructions on how to set up a Raspberry PI.  After installing the correct software on my developer workstation, flashing the SD card with win10, plugging the SD card into the PI, turning the PI on, and then remoting into the PI via powershell, I could see the PI on my local workstation via the Windows IoT Core Watcher and the PI showing its friendly welcome screen via HDMI.

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I then headed over to Visual Studio and copy/pasted the equisite “Hello IoT World” Blinky project to the Pi and watched the light go on and off.

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With that out of the way, I decided to look at controlling the light via Twitter and Azure.  The thought was to have the PI monitor a message queue on Azure and whenever there was a message, blink on or off (simulating the ejectabed being activated).  To that end, I went into Azure and created a basic storage account.  One of the nice things about Azure is that you get a queue out of the box when you create a storage account:

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One of the not so nice things about Azure is that there is no way to control said Queue via their UI.  You have to create, push, and pull from the queue in code.  I went back to visual studio and added in the Azure Storage Nuget package

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I then created a method to monitor the queue
1 internal async Task<Boolean> IsMessageOnQueue() 2 { 3 var storageConnectionString = "DefaultEndpointsProtocol=https;AccountName=ejectabed;AccountKey=xxx"; 4 var storageAccount = CloudStorageAccount.Parse(storageConnectionString); 5 var client = storageAccount.CreateCloudQueueClient(); 6 var queue = client.GetQueueReference("sloan"); 7 var queueExists = await queue.ExistsAsync(); 8 if (!queueExists) 9 { 10 GpioStatus.Text = "Queue does not exist or is unreachable."; 11 return false; 12 } 13 var message = await queue.GetMessageAsync(); 14 if (message != null) 15 { 16 await queue.DeleteMessageAsync(message); 17 return true; 18 } 19 GpioStatus.Text = "No message for the EjectABed."; 20 return false; 21 } 22

Then if there is a message, the PI would run the ejection sequence (in this case blink the light)
1 internal void RunEjectionSequence() 2 { 3 bedCommand.Eject(); 4 bedTimer = new DispatcherTimer(); 5 bedTimer.Interval = TimeSpan.FromSeconds(ejectionLength); 6 bedTimer.Tick += LightTimer_Tick; 7 bedTimer.Start(); 8 }

 

I deployed the code to the PI without a problem.  I then created a Basic console application to push messages to the queue that the PI could drain
1 class Program 2 { 3 static String storageConnectionString = "DefaultEndpointsProtocol=https;AccountName=ejectabed;AccountKey=xxx"; 4 5 static void Main(string[] args) 6 { 7 Console.WriteLine("Start"); 8 Console.WriteLine("Press The 'E' Key To Eject. Press 'Q' to quit..."); 9 10 var keyInfo = ConsoleKey.S; 11 do 12 { 13 keyInfo = Console.ReadKey().Key; 14 if (keyInfo == ConsoleKey.E) 15 { 16 CreateQueue(); 17 WriteToQueue(); 18 //ReadFromQueue(); 19 } 20 21 } while (keyInfo != ConsoleKey.Q); 22 23 Console.WriteLine("End"); 24 Console.ReadKey(); 25 } 26 27 private static void CreateQueue() 28 { 29 var storageAccount = CloudStorageAccount.Parse(storageConnectionString); 30 var client = storageAccount.CreateCloudQueueClient(); 31 var queue = client.GetQueueReference("sloan"); 32 queue.CreateIfNotExists(); 33 Console.WriteLine("Created Queue"); 34 } 35 36 private static void WriteToQueue() 37 { 38 var storageAccount = CloudStorageAccount.Parse(storageConnectionString); 39 var client = storageAccount.CreateCloudQueueClient(); 40 var queue = client.GetQueueReference("sloan"); 41 var message = new CloudQueueMessage("Eject!"); 42 queue.AddMessage(message); 43 Console.WriteLine("Wrote To Queue"); 44 } 45 46 47 private static void ReadFromQueue() 48 { 49 var storageAccount = CloudStorageAccount.Parse(storageConnectionString); 50 var client = storageAccount.CreateCloudQueueClient(); 51 var queue = client.GetQueueReference("sloan"); 52 var queueExists = queue.Exists(); 53 if (!queueExists) 54 Console.WriteLine("Queue does not exist"); 55 var message = queue.GetMessage(); 56 if (message != null) 57 { 58 queue.DeleteMessage(message); 59 Console.WriteLine("Message Found and Deleted"); 60 } 61 else 62 { 63 Console.WriteLine("No messages"); 64 } 65 } 66

I could then Write to the queue and the PI would read and react.  You can see it in action here:

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With the queue up and running, I was ready to add in the ability for someone to Tweet to the queue.  I created a cloud service project and pointed to a new project that will monitor Twitter and then push to the queue:

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The Twitter project uses the TweetInvi nuget package and is a worker project.  It makes a call to Twitter every 15 seconds and if there is a tweet to “ejectabed” with a person’s name, it will write to the queue (right now, only Sloan’s name is available)
1 type TwitterWorker() = 2 inherit RoleEntryPoint() 3 4 let storageConnectionString = RoleEnvironment.GetConfigurationSettingValue("storageConnectionString") 5 6 let createQueue(queueName) = 7 let storageAccount = CloudStorageAccount.Parse(storageConnectionString) 8 let client = storageAccount.CreateCloudQueueClient() 9 let queue = client.GetQueueReference(queueName); 10 queue.CreateIfNotExists() |> ignore 11 12 let writeToQueue(queueName) = 13 let storageAccount = CloudStorageAccount.Parse(storageConnectionString) 14 let client = storageAccount.CreateCloudQueueClient() 15 let queue = client.GetQueueReference(queueName) 16 let message = new CloudQueueMessage("Eject!") 17 queue.AddMessage(message) |> ignore 18 19 let writeTweetToQueue(queueName) = 20 createQueue(queueName) 21 writeToQueue(queueName) 22 23 let getKeywordFromTweet(tweet: ITweet) = 24 let keyword = "sloan" 25 let hasKeyword = tweet.Text.Contains(keyword) 26 let isFavourited = tweet.FavouriteCount > 0 27 match hasKeyword, isFavourited with 28 | true,false -> Some (keyword,tweet) 29 | _,_ -> None 30 31 32 override this.Run() = 33 while(true) do 34 let consumerKey = RoleEnvironment.GetConfigurationSettingValue("consumerKey") 35 let consumerSecret = RoleEnvironment.GetConfigurationSettingValue("consumerSecret") 36 let accessToken = RoleEnvironment.GetConfigurationSettingValue("accessToken") 37 let accessTokenSecret = RoleEnvironment.GetConfigurationSettingValue("accessTokenSecret") 38 39 let creds = Credentials.TwitterCredentials(consumerKey, consumerSecret, accessToken, accessTokenSecret) 40 Tweetinvi.Auth.SetCredentials(creds) 41 let matchingTweets = Tweetinvi.Search.SearchTweets("@ejectabed") 42 let matchingTweets' = matchingTweets |> Seq.map(fun t -> getKeywordFromTweet(t)) 43 |> Seq.filter(fun t -> t.IsSome) 44 |> Seq.map (fun t -> t.Value) 45 matchingTweets' |> Seq.iter(fun (k,t) -> writeTweetToQueue(k)) 46 matchingTweets' |> Seq.iter(fun (k,t) -> t.Favourite()) 47 48 Thread.Sleep(15000) 49 50 override this.OnStart() = 51 ServicePointManager.DefaultConnectionLimit <- 12 52 base.OnStart()

Deploying to Azure was a snap
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And now when I Tweet,
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the PI reacts.  Since Twitter does not allow the same Tweet to be sent again, I deleted it every time I wanted to send a new message to the queue.