Brian Ritchie

5 steps to better software estimates

Mon, 14 Mar 2016 14:36:02 GMT

Schedules are critical to business. They help us plan and coordinate efforts across teams. The problem with schedules is they are based on estimates.

In software development, estimates are challenging. A new section of code is rarely identical to past work, making comparisons difficult. To make matters worse, the new code usually integrates with or modifies existing code. This is where things usually go sideways. And if that doesn't do it, there are usually the unexpected build issues, deployment problems, or various interruptions.

Here are some ideas to help with your estimates...

Read Full Post: https://www.linkedin.com/pulse/5-steps-better-software-estimates-brian-ritchie

The fallacies of distributed computing

Sat, 05 Mar 2016 23:35:00 GMT

Building distributed systems can be complex undertaking. This makes solid architecture, design, coding, and testing all critical to success. Failure at any of these points can lead to degraded performance, unhandled failures, unplanned expenses required to redesign the system, and ultimately lost customers.

The eight fallacies of distributed computing were asserted by Peter Deutsch, James Gosling and others at Sun Microsystems. These false assumptions serve as a guide and warning to all of us building distributed systems.

The eight fallacies are:

The network is reliable.
Latency is zero.
Bandwidth is infinite.
The network is secure.
Topology doesn't change.
There is one administrator.
Transport cost is zero.
The network is homogeneous.

While this guidance was laid out twenty years ago, we are still making these mistakes today. These mistakes show up as unsecured endpoints, timeouts due to serialization of large objects, lost transactions, slow performance, and more. Averting these mistakes means considering these fallacies during every design and code review. It is critical that we challenge our teams to make this part of their DNA.

To learn more, please referrer to this white paper:
http://www.rgoarchitects.com/Files/fallacies.pdf

Packt offers buy one, get one free book offer

Wed, 26 Mar 2014 03:50:00 GMT

Packt Publishing has published their 2000th book! You can buy my book RavenDB: High Performance and many more from Packt in this amazing Buy One, Get One Free offer http://bit.ly/1j26nPN

Playing Spotify (and other audio) via AirPlay

Tue, 17 Dec 2013 02:48:00 GMT

Two of my favorite things working together: Spotify & AirPlay. This tip lets you play your Spotify library for free on your home theatre!

If you have a Mac, simply hold down the option key when you click on the audio menu option. You can then send just the audio to an Apple TV or AirPort. If you're on Windows, you'll need to use something like Airfoil for Windows.

Take a look at this article from Cult of Mac for other cool uses for the option key.

Reviews: RavenDB High Performance

Fri, 13 Dec 2013 02:39:00 GMT

My book RavenDB High Performance was recently published by Packt Publishing. The team at Packt was great to work with and I had support from a strong group of reviewers: Ayende Rahien (of RavenDB fame), Paul Stovell (founder of Octopus Deploy), and Mohammed Ibrahim.

I really enjoyed writing the book and hope that readers enjoy reading it! The goal of the book was to dig into the advanced topics that would help developers take their applications to the next level. Once you get the basics down, this book will help you optimize your applications for higher levels of scalability and functionality.

Need more encouragement to get a copy? :)

Ayende Rahien
"To summarize, go ahead and do the cool stuff first. But pay attention to the whole book. I think that Brian has done an excellent job in getting the crucial information you need to really get the most from RavenDB. And this book is one of the best ways to go from being merely proficient to being absolutely awesome." [ From the book's forward ]

Brian Federici
"In some ways, I found the book easier to follow than the online RavenDB documentation. While it's not extensive enough to replace the online docs, I found the organization of the book to be more logical and it did a better job of surfacing the core knowledge you'd need day-to-day." [ Full Review ]

Sebastian Gebski
"The best book on RavenDB that is available currently (but not for absolute beginners!) This book is a clear win - it's a short but very practical guide to the most crucial aspects of RavenDB. To summarize: if you're considering RavenDB for your product / service, give this book a go, it will help you to understand what's Raven capable of." [ Full Review ]

Johnny Graber
"There are many tricks to squeeze more performance out of the API. Most of them are not part of the official documentation and when only as a comment to a more general topic. Brian made a big effort to collect them. And luckily for us he can explain them in a beginner-friendly way as well." [ Full Review ]

I really appreciate the kind words of these reviewers. This is my first book and I tried to pour into it the things that I would want to learn if I were buying a book on RavenDB. Please check it out and let me know what you think.

Moving from an entity model to a RavenDB document model

Sun, 15 Sep 2013 03:06:00 GMT

I have an application that I'm moving from a SQL Server database to a RavenDB Document Database. The first order of business is updating the data model. Document data modeling and relational data modeling are totally different.

Below is part of the data model. It contains the relationship between Camps & Programs. For this application, a camp can have multiple programs. A program is a specific type of activity program for a given age or grade. For example, a sports summer camp may have a baseball program for 2nd to 4th grade. In a relational database this concept is actually fairly complex to model.

Entity Relationship Model

While the relational database model is fairly complex and will require lots of joins to access, the corresponding document data model is nice and simple.

Document Data Model

There are two documents. The Camp document contains a collections of references to the related Program document. While you could model this as one big document, the application allows users to search at the Program level & schedules Campers at the program level. This is why the Program document is separate.

The JSON for a Camp looks like the following:

camps/ce87d45b-87dc-4d23-a67e-06de97235d8b
{
"Name": "High School Sports Camp",
"Contacts": [
    {
      "Type": "Staff",
      "Name": "Kathleen Smith",
      "EmailAdress": "katsmith9919@gmail.com"
    }
],
"Programs": [
    {
      "Id": "programs/75df8120-5f98-479f-bb2c-b0748b6c063d",
      "Name": "Baseball Camp - Session 1"
    },
    {
      "Id": "programs/762ee139-5470-4eb6-9142-501e217c26f0",
      "Name": "Baseball Camp - Session 2"
    }
]
}

And the JSON for a related Program:

programs/762ee139-5470-4eb6-9142-501e217c26f0
{
"CampId": "camps/ce87d45b-87dc-4d23-a67e-06de97235d8b",
"CampName": "High School Sports Camp",
"Category": "Sports",
"Name": "Baseball Camp - Session 2",
"Ages": [],
"Grades": [
    9,
    10,
    11,
    12
]
}

The nice thing about document models is you can also denormalize data to improve access. In this example, I've included the Camp Name in the Program Document and the Program Name in the Camp document. This saves additional document loads to get basic information.

Hopefully this gives you some insight into document data modeling. It is key to building an efficient, easy to develop applications.

My new book, RavenDB High Performance, covers this topic in depth and much more. I encourage you to check it out if you are building document databases.

A technique for computed columns in LINQ-based EF queries

Fri, 13 Sep 2013 02:21:00 GMT

Have you seen this message before?

LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression.

It is one of my favorite LINQ to EF messages! LINQ is pretty smart at translating C# expressions into SQL. But, there are lots of simple things that can blow its mind. Here is an example:

                var camps = from c in db.Camps
                            select new {
                                CampId = "camps/"+c.CampId
                            };

This error will occur if CampId is a Guid. It can also occur if you are trying to call a function or perform some sort of complex manipulation.

A easy way to solve this problem is to put the results of the query into a class with computed properties. It might be tempting to put this logic into a constructor. However, LINQ to EF only supports parameterless constructors so this would be a no-go.

Here is an example:

   public class Camp
    {
        public string CampId { get; set; }
        public Guid CampGuid
        {
            set
            {
                CampId = "camps/" + value;
            }
        }
   }

   var camps = from c in db.Camps
                        select new Camp {
                                CampGuid = c.CampId
                         };

The nice thing about this approach is the CampGuid property won't be serialized to JSON since it only has a setter.

Alternatively, you could have the getter do the calculation:

   public class Camp
    {
        public string CampId
        {
            get
            {
                return "camps/" + CampGuid;
            }
        }

        public Guid CampGuid { get; set; }
   }

This even works with more complex examples. In this case, I have a model that is being serialized to JSON. The JavaScript is expecting the dates in Unix format, while EF returns the dates in a C# DateTime class. The same technique can solve this problem as well:

    public class CalendarEventModel
    {
        private long ToUnixTimespan(DateTime date)
        {
            TimeSpan tspan = date.ToUniversalTime().Subtract(new DateTime(1970, 1, 1, 0, 0, 0));
            return (long)Math.Truncate(tspan.TotalSeconds);
        }

        public DateTime startDT { get; set; }
        public DateTime endDT { get; set; }
        public long start { get { return ToUnixTimespan(startDT); } }
        public long end { get { return ToUnixTimespan(endDT); } }
   }

   var q = from schedule in db.CamperSchedules
                select new CalendarEventModel()
        {
              startDT = schedule.StartDateTime,
              endDT = schedule.EndDateTime
        };

Creating your development home page using GitHub Pages

Mon, 09 Sep 2013 00:52:00 GMT

It was time to update my developer home page. In the past, I've been focused on using server-side technology to create the page. However, times have changes & the server-side isn't all that important for this site. It was more important to have something that was easy to maintain & super-low cost.

Enter GitHub Pages. It gives you versioning, automated publishing, custom domain names, and it is free!

Here is my new site using responsive (and mobile friendly) HTML5 site beside my old and busted site.

To setup the site with GitHub:

Create a new repository. I called mine "pages".
If you want to use a built-in template, click Settings->Automatic Page Generator
see https://help.github.com/articles/creating-pages-with-the-automatic-generator
If you want to upload your own HTML, create a branch called gh-pages, clone the branch and commit your files
see https://help.github.com/articles/creating-project-pages-manually

Now your site is available at http://username.github.io/projectname. In my case, http://dotnetpowered.github.io/pages.

If you want to point your own domain, create a CNAME file in the root folder containing your domain name. Next, point your DNS A record at 204.232.175.78. See https://help.github.com/articles/setting-up-a-custom-domain-with-pages

Learn more about this functionality at http://pages.github.com. See my repository for an example.

CQRS at Jax Code Camp 2012

Wed, 10 Oct 2012 04:53:00 GMT

Continuing my CQRS world tour...I gave my CQRS presentation at the Jax Code Camp 2012 this past Saturday. It was a great crowd with lots of representation from the wicked smart engineers at Feature[23] and others from the Jacksonville developer community.

If you'd like to take a look at my slide deck, they are out on SlideShare. The code I demoed is from Ashic Mahtab and is posted on github.

If you can't get enough of CQRS, Microsoft has joined the CQRS party with their CQRS Journey which includes a free e-book called Exploring CQRS and Event Sourcing.

Come out for a CQRS presentation at the JAX Architecture Group

Mon, 27 Feb 2012 13:57:00 GMT

I'm giving a talk on CQRS at the Jacksonville Architecture Group on Tuesday (2/28) at 6pm.

Come out, get some pizza, and enjoy some CQRS.

Hope to see you there!

UPDATE: Slides posted on SlideShare.

Hosting Windows Services in IIS Presentation at JAXDUG

Thu, 06 Oct 2011 01:53:00 GMT

Thanks to everyone who came out for my presentation at the Jacksonville Developer User Group tonight.

Here are the slides on SlideShare.
Download the code for building your own service with self-hosted monitoring from BitBucket.
You can also read my earlier blog post Death to Windows Services...Long Live IIS.

Migrating from ASPX MVC views to Razor

Sat, 03 Sep 2011 13:36:00 GMT

Razor-based view templates are a much cleaner way to construct MVC views in ASP.NET. However, they were only released fairly recently with MVC3.

If you still have some ASPX-based templates that you'd like to upgrade, Telerik has released a free tool to do just that.

Web-based Farm Monitor for your Web Farm Framework Deployment

Fri, 02 Sep 2011 00:41:00 GMT

In my recent posts on scalability, I've mentioned the Web Farm Framework (WFF) as a solution for managing a farm of IIS servers. It adds a nice management Server Farm management UI into the IIS Manager.

It is a nice tool, but is only accessible via the windows interface. To make the farm more accessible, I've created a basic farm monitor MVC web site using the WFF .NET API.

Here are a couple of screen shots of it in action:

It uses a few cool features of the API:

Getting a list of nodes in the farm & their status
```
Microsoft.Web.Farm.WebFarmManager manager = new Microsoft.Web.Farm.WebFarmManager();            
foreach (var farm in manager.WebFarms)
{
    foreach (var node in farm.Servers)
    {
    }
}
```

CPU/Memory monitoring. See my sparkline post to learn how to create these kinds of infographics.

PercentageCPU = node.Counters.ProcessorTime/100;
MemoryAvailableKBytes = node.Counters.MemoryAvailableKBytes;
PercentageMemoryAvailable = 1.0f - node.Counters.PercentageMemoryAvailable

Getting a list of running processes
```
private static ServerProcess[] GetNodeProcesses(string farmName, string nodeName)
{
    var manager = new Microsoft.Web.Farm.WebFarmManager();
    var farm = manager.WebFarms[farmName];
    var server = farm.Servers[nodeName];
    var processes = server.RunOperation(farm.CreateRunOperationOptions("GetProcesses")) as ServerProcess[];
    return processes;
}
```

Download the source for the project if you'd like to take it for a spin. Make sure the web site's application pool has enough permissions to access the web farm.

Using the .NET Chart API to add sparklines to your MVC site

Wed, 31 Aug 2011 02:38:00 GMT

In my last post, I introduced sparklines and showed you how to generate them using the Google Chart API. Using an external API may not be appropriate for all applications, so here is a way to generate the sparkline using the .NET Chart API.

Over at the Better Dashboards Blog, they provide some sample code for calling the chart API. The following shows how to make it reusable for your MVC application.

First, we'll create a custom ActionResult to return the image for our sparkline:

    public class SparklineResult : FileResult
    {
        IEnumerable<float> samples;
        int SparklineWidth;
        int SparklineHeight;
        public SparklineResult(int width, int height, IEnumerable<float> samples) : base("image/png")
        {
            this.samples = samples;
            this.SparklineHeight = height;
            this.SparklineWidth = width;
        }
        protected override void WriteFile(HttpResponseBase response)
        {
            var sparklineImage = GetSparkLineImage(samples, SparklineWidth, SparklineHeight);
            response.ContentType = "image/png";
            response.BinaryWrite(sparklineImage);
        }
        private static byte[] GetSparkLineImage(IEnumerable<float> samples, int width, int height)
        {
            var chart = new Chart();
            var series = new Series();
            chart.Series.Add(series);
            // Sparklines use the 'Spline' chart type to show a smoother trend with a line chart
            series.ChartType = SeriesChartType.Spline;
            // Since the line is the only thing you see on the chart, you might want to
            // increase its width. Interestingly, you need to set the BorderWidth property
            // in order to accomplish that.
            series.BorderWidth = 2;
            // Add samples to the series
            int i = 0;
            foreach (var sample in samples)
            {
                i++;
                // Add 5 to the sample so line does not get cut off at the bottom of the image
                chart.Series[0].Points.AddXY(DateTime.Now.AddDays(i), sample + 5);
            }
            // Start hiding both sets of axes, labels, gridlines and tick marks
            var chartArea = new ChartArea();
            chart.ChartAreas.Add(chartArea);
            chartArea.AxisX.LabelStyle.Enabled = false;
            chartArea.AxisY.LabelStyle.Enabled = false;
            chartArea.AxisX.MajorGrid.Enabled = false;
            chartArea.AxisY.MajorGrid.Enabled = false;
            chartArea.AxisX.MajorTickMark.Enabled = false;
            chartArea.AxisY.MajorTickMark.Enabled = false;
            chartArea.AxisX.LineWidth = 0;
            chartArea.AxisY.LineWidth = 0;
            chartArea.AxisY.Minimum = 0;
            // Add an extra 5 pixels since the samples were adjusted up by 5
            // this prevents the line from being truncated
            chartArea.AxisY.Maximum = 105;
            // Re-adjust the size of the chart to reduce unnecessary white space
            chart.Width = width;
            chart.Height = height;
            // Get bytes of PNG image
            var s = new MemoryStream();
            chart.SaveImage(s, ChartImageFormat.Png);
            s.Position = 0;
            return s.ToArray();
        }
    }

Next, we'll utilize the SparklineResult in a controller. The controller will serve the image data for the sparkline back to the calling page.

    public class ChartController : Controller
    {
        public ActionResult Sparkline(int width, int height, string samples)
        {
            return new SparklineResult(width, height, (from s in samples.Split(',') select float.Parse(s)).ToArray());
        }
    }

Next, we'll create a HTML helper method to generate the img tag which will fetch the image from our controller.

        public static MvcHtmlString DrawSparkline(this HtmlHelper helper, int width, int height, IEnumerable<int> plotData)
        {
            string sparkUrl = "<img src='/chart/sparkline?width={0}&height={1}&samples={2}'/>";
            string sparkLine = String.Format(sparkUrl, width, height, String.Join(",", plotData));
            return MvcHtmlString.Create(sparkLine);
        }

Now we can call the helper method from our Razor template:

       @Html.DrawSparkline(70, 20, new int[14] { 1, 4, 2, 6, 20, 30, 1, 23, 14, 2, 41, 2, 33, 21 })

Which produces the following sparkline:

You can download my sample project that puts it all together. This includes both the Google API & .NET API methods.

Adding sparklines to your MVC site using the Google Chart API

Sun, 28 Aug 2011 03:37:00 GMT

Sparklines present trends and variations associated with some measurement in a very compact form. The term & concept was proposed by Ed Tufte. This form of information graphic has become very popular for dashboards. In this post, I'll show how add sparklines to your site using a custom HTML Helper method to generate code accessing the Google Chart API. In my next post, I'll show you how to add sparklines using the .NET charting API.

The folks over at Data Driven wrote a post about using the Google Chart API to render a sparkline. The following shows how to take this concept & make it reusable by your MVC application.

Code for the extension method:

        public static MvcHtmlString DrawSparkline(this HtmlHelper helper, int width, int height, IEnumerable<int> plotData,
            string bgColor, string lineColor, string labelColor)
        {
            int? max = plotData.Max();
            int? min = plotData.Min();
            string list = String.Join(",", plotData);
            string sparkUrl = "<img src='http://chart.apis.google.com/" +
                 "chart?cht=lc&chf=bg,s,{6}&cgh=0,50,1,0&chds={0},{1}&chs={2}x{3}&chd=t:{4}&chco={8}" +
                 "&chls=1,1,0&chm=o,{7},0,20,4&chxt=r,x,y&chxs=0,{7},11,0,_|1,{7},1,0,_|2,{7},1,0,_&chxl=0:|{5}|1:||2:||'/>";
            string sparkLine = String.Format(sparkUrl, min, max, width, height, list, plotData.Last(), bgColor, labelColor, lineColor);
            return MvcHtmlString.Create(sparkLine);
        }

And here is an example of calling the HTML helper from a MVC Razor template:

@Html.DrawSparkline(70, 20, new int[14] { 1, 4, 2, 6, 20, 30, 1, 23, 14, 2, 41, 2, 33, 21 }, "ffffff", "999999", "990000")

Which produces the following sparkline:

Scaling Out .NET Presentation at Jax Code Camp 2011

Sat, 27 Aug 2011 16:49:00 GMT

Today at the Jax Code Camp I gave a presentation on scaling out your .NET applications by leveraging IIS7, AppFabric, Web Farm Framework, and Web Deploy. Thanks to everyone how come out to the session.

I've posted the presentation over at SlideShare and here are some related blog posts that I mentioned during the talk:

Need further reading?

» Web Farm Framework

˃Web Farm Framework
http://www.iis.net/download/WebFarmFramework

˃Scott Gu’s Introduce to WFF 2.0
http://weblogs.asp.net/scottgu/archive/2010/09/08/introducing-the-microsoft-web-farm-framework.aspx

˃WFF Documentation (including API & Powershell)
http://learn.iis.net/page.aspx/905/microsoft-web-farm-framework-20-for-iis-7//

» Windows AppFabric

˃AppFabric Architecture Guide
http://blogs.msdn.com/b/yasserabdelkader/archive/2010/09/12/release-of-windows-server-appfabric-architecture-guide.aspx

˃AppFabric Management Pack for Op Mgr 2007
http://blogs.technet.com/b/appfabric/archive/2010/06/14/appfabric-management-pack-available-for-operations-manager-2007.aspx

˃AppFabric Presentation
http://rstonkus.wordpress.com/2010/10/28/partner-conference-windows-server-appfabric//

» Other

˃Memcached ASP.NET Providers
http://memcachedproviders.codeplex.com/

˃SQL Table Queues
http://www.mssqltips.com/tip.asp?tip=1257

˃Web Deploy Team Blog
http://blogs.iis.net/msdeploy/default.aspx

˃Application Request Routing
http://www.iis.net/download/ApplicationRequestRouting
http://learn.iis.net/page.aspx/486/http-load-balancing-using-application-request-routing//
http://blogs.iis.net/mailant/archive/2010/03/25/how-iis-application-request-routing-arr-powers-elastic-scale-for-maximumasp.aspx

F5 Add-on for Web Farm Framework

Sat, 27 Aug 2011 16:24:00 GMT

Gupreet over on the IIS.NET site posted a sample for integrating an F5 load balancer with the Web Farm Framework. It works well, but isn't configurable. I started adding my own configuration, but artisticcheese posted a project to CodePlex that already has this functionality.

To install, download the extension and perform the following:

Create pool on F5 load balanacer with exactly the same name on WFF. Do not add any farm members yet.
Stop WFF service
Create folder "%programfiles%\IIS\Microsoft Web Farm Framework\extensions" and put all files in distribution into that folder
Modify "F5LoadBalancer.dll.config" file to point to active node of F5 loadbalancer and authentication credentials
Copy "icontrol.dll" into "%programfiles%\IIS\Microsoft Web Farm Framework"
Open "%systemroot%\system32\inetsrv\config\applicationHost.config" and edit XML node below by adding attribute in bold <webFarm name="DevWebFarm" enabled="true" primaryServer="webnode1" loadBalancerProvider="F5">
Start WFF service

iControl.dll is an assembly provided by BigIP giving you a .NET API to control your F5 Local Traffic Balancer.

Now that you have it installed, WFF will automatically take nodes online & offline thru the F5 as needed. This supports rolling deployments and more.

Internet Explorer 9 is coming Monday to a web near you

Fri, 11 Mar 2011 00:01:00 GMT

Internet Explorer 9 is finally here...well almost. Microsoft is releasing their new browser on March 14, 2011.

IE9 has a number of improvements, including:

Faster, Faster, Faster. Did I mention it is faster? With the new browsers coming out from Mozilla, Google, and Microsoft, there have been a flood of speed test coverage. Chrome has long held the javascript speed crown. But according to Steven J. Vaughan-Nichols over at ZDNET..."for the moment at least IE9 is actually the fastest browser I’ve tested to date." He came to this revelation after figuring out that the 32-bit version of IE9 has the new Chakra JIT (the 64-bit version doesn't). It also has a DirectX-based rendering engine so it can do cool tricks once reserved for desktop applications.
Windows 7 Desktop Integration. Read my post for more details. Unfortantely, they didn't integrate my ideas...at least not yet :)
Hot new UI. Ok, they "borrowed" some ideas from Chrome...but that is the best form of flattery.
Standards Compliance. A real focus on HTML5 and CSS3. Definite goodness for developers.

So, go get yourself some IE9 on Monday and enjoy!

Microsoft releases Visual Studio 2010 SP1

Wed, 09 Mar 2011 02:50:00 GMT

Microsoft has been beta testing SP1 since December of last year. Today, it was released to MSDN subscribers and will be available for public download on March 10, 2011.

The service pack includes a slew of fixes, and a number of new features:

Silverlight 4 support
Basic Unit Testing support for the .NET Framework 3.5
Performance Wizard for Silverlight
IntelliTrace for 64-bit and SharePoint
IIS Express support
SQL CE 4 support
Razor support
HTML5 and CSS3 support (IntelliSense and validation)
WCF RIA Services V1 SP1 included
Visual Basic Runtime embedding
ALM Improvements

Of all the improvements, IIS Express probably has the largest impact on web developer productivity.

According to Scott Gu, it provides the following:

It’s lightweight and easy to install (less than 10Mb download and a super quick install)
It does not require an administrator account to run/debug applications from Visual Studio
It enables a full web-server feature set – including SSL, URL Rewrite, Media Support, and all other IIS 7.x modules
It supports and enables the same extensibility model and web.config file settings that IIS 7.x support
It can be installed side-by-side with the full IIS web server as well as the ASP.NET Development Server (they do not conflict at all)
It works on Windows XP and higher operating systems – giving you a full IIS 7.x developer feature-set on all OS platforms

IIS Express (like the ASP.NET Development Server) can be quickly launched to run a site from a directory on disk. It does not require any registration/configuration steps. This makes it really easy to launch and run for development scenarios.

Good stuff indeed. This will make our lives much easier. Thanks Microsoft...we're feeling the love!

Retrieving recent tweets using LINQ

Sun, 06 Mar 2011 01:50:00 GMT

There are a few different APIs for accessing Twitter from .NET. In this example, I'll use linq2twitter. Other APIs can be found on Twitter's development site.

First off, we'll use the LINQ provider to pull in the recent tweets.

   1:  public static Status[] GetLatestTweets(string screenName, int numTweets)

   2:  {

   3:      try

   4:      {

   5:          var twitterCtx = new LinqToTwitter.TwitterContext();

   6:          var list = from tweet in twitterCtx.Status

   7:                      where tweet.Type == StatusType.User &&

   8:                                 tweet.ScreenName == screenName

   9:                      orderby tweet.CreatedAt descending

  10:                      select tweet;

  11:          // using Take() on array because it was failing against the provider

  12:          var recentTweets = list.ToArray().Take(numTweets).ToArray();

  13:          return recentTweets;

  14:      }

  15:      catch

  16:      {

  17:          return new Status[0];

  18:      }

  19:  }

Once they have been retrieved, they would be placed inside an MVC model.

Next, the tweets need to be formatted for display. I've defined an extension method to aid with date formatting:

   1:  public static class DateTimeExtension

   2:  {

   3:      public static string ToAgo(this DateTime date2)

   4:      {

   5:          DateTime date1 = DateTime.Now;

   6:          if (DateTime.Compare(date1, date2) >= 0)

   7:          {

   8:              TimeSpan ts = date1.Subtract(date2);

   9:              if (ts.TotalDays >= 1)

  10:                  return string.Format("{0} days", (int)ts.TotalDays);

  11:              else if (ts.Hours > 2)

  12:                  return string.Format("{0} hours", ts.Hours);

  13:              else if (ts.Hours > 0)

  14:                  return string.Format("{0} hours, {1} minutes",

  15:                         ts.Hours, ts.Minutes);

  16:              else if (ts.Minutes > 5)

  17:                  return string.Format("{0} minutes", ts.Minutes);

  18:              else if (ts.Minutes > 0)

  19:                  return string.Format("{0} mintutes, {1} seconds",

  20:                         ts.Minutes, ts.Seconds);

  21:              else

  22:                  return string.Format("{0} seconds", ts.Seconds);

  23:          }

  24:          else

  25:              return "Not valid";

  26:      }

  27:  }

Finally, here is the piece of the view used to render the tweets.

   1:  <ul class="tweets">

   2:  <%

   3:      foreach (var tweet in Model.Tweets)

   4:      {

   5:   %>

   6:       <li class="tweets">

   7:       <span class="tweetTime"><%=tweet.CreatedAt.ToAgo() %> ago</span>:

   8:          <%=tweet.Text%>

   9:          </li>

  10:   <%} %>

  11:  </ul>