Off the record

Key satement : design for mobile first

Media queries : 2 ways to define :

<link href="css/phone.css" rel="stylesheet" type="text/css" media="only screen and (max-width: 400px)" >

OR

@media screen and (min-width: 900px) {

 .class {
   background: #666;
 }

}

Websockets !

using System;
using System.Windows;
using System.Windows.Media;
using System.Windows.Shapes;
using System.Windows.Media.Effects;
using System.Windows.Controls;
using System.Media;

namespace WPFApplication
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            Window win = new Window();
            win.Title = "Hello world";  

            win.Height = 383;
            win.Width = 480;

            // change background color
            win.Background = new LinearGradientBrush(Colors.LightSeaGreen, Colors.Yellow, 45.0);

            // add an eventHandler to be run on window initialization
            win.Initialized += new EventHandler(w_Initialized);

            win.AddHandler(Control.MouseLeftButtonDownEvent, new RoutedEventHandler(OnClick));

            Application app = new Application();
            app.Run(win);

        }

        static void OnClick(object sender, RoutedEventArgs e)
        {
            if (e.Source is Ellipse)
            {
                SoundPlayer sp = new
                SoundPlayer(@"c:\windows\media\tada.wav");
                sp.Play();
            }
        }   

        static void w_Initialized(object window, EventArgs e)
        {
            Ellipse ellipse = new Ellipse();

            // add new eventsHandler to interact with the mouse
            ellipse.MouseEnter += new System.Windows.Input.MouseEventHandler(ellipse_MouseEnter);
            ellipse.MouseLeave += new System.Windows.Input.MouseEventHandler(ellipse_MouseLeave);
            
            ellipse.Width = 100;
            ellipse.Stroke = Brushes.Red;
            ellipse.StrokeThickness = 1;

            ImageBrush brush = new ImageBrush();
            ImageSourceConverter imageSourceConverter = new ImageSourceConverter();
            brush.ImageSource = (ImageSource) imageSourceConverter.ConvertFrom(@"c:\paper.jpg");
            ellipse.Fill = brush;

            ((Window)window).Content = ellipse;

        }

        static void ellipse_MouseEnter(object sender, EventArgs e) {
            Ellipse ellipse = (Ellipse)sender;
            OuterGlowBitmapEffect effect = new OuterGlowBitmapEffect();
            effect.GlowColor = Colors.DeepPink;
            effect.GlowSize = 10;
            ellipse.BitmapEffect = effect;
        }
        static void ellipse_MouseLeave(object sender, EventArgs e)
        {
            Ellipse ellipse = (Ellipse)sender;
            ellipse.BitmapEffect = null;
        }
    }
}

Define a service to expose logic. Expose the interface to this logic at a certain endpoint, certain channel (in our case BasicHTTPBinding).

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using DM.PetShop;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            // service relies on an implementation   
            ServiceHost host = new ServiceHost(typeof(OrderService));

            // service is exposed through the intreface (i.e. contract)
            host.AddServiceEndpoint(typeof(IOrderContract), new BasicHttpBinding(), "http://localhost:9000/PetShop");

            // open the service ("fire and forget" call)
            host.Open();

            // make sure the service doesn't die and print status
            Console.Title = String.Format("{0} is running ...", host.Description.Endpoints[0].Address);
            Console.Write("Server started. Press enter to stop..."); 
            Console.ReadLine();

            // close after receiving a keystroke
            host.Close();
            Console.WriteLine("Server stoppped. Press enter to quit...");
            Console.ReadLine();

        }
    }
}

Here is the contract (a.k.a. interface) that will be exposed to the world

using System.ServiceModel;

namespace DM.PetShop
{
    [ServiceContract(Name = "PetShopOrderContract", Namespace = Constants.SERVICE_NAMESPACE)]
    public interface IOrderContract
    {
        [OperationContract(Name = "PlaceOrder", Action = "PlaceOrder", ReplyAction = "PlaceOrderReply")]
        void PlaceOrder(string orderData);
    }
}

Here the implementation (note the annotations,most important part)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;

namespace DM.PetShop
{
    [ServiceBehavior(Name = "DM.PetShop.OrderService", Namespace = Constants.SERVICE_NAMESPACE)]
    public class OrderService : IOrderContract
    {
        public void PlaceOrder(string orderData)
        {
            Console.WriteLine("Diagnostic message !");
        }
    }
}

Then write a client :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using System.ServiceModel.Channels;
using IOrderContractChannelFactory = System.ServiceModel.ChannelFactory;
using DM.PetShop;

namespace Project_Client1
{
    class Client1App
    {
        static void Main(string[] args)
        {
            IOrderContractChannelFactory factory = new IOrderContractChannelFactory(new BasicHttpBinding());
            IOrderContract channel = factory.CreateChannel(new EndpointAddress("http://localhost:9000/PetShop/"));
            channel.PlaceOrder("1 parrot");

            IClientChannel clientChannel = (IClientChannel)channel;
            try
            {
                if (clientChannel.State != CommunicationState.Closed)
                    clientChannel.Close();
            }
            catch
            {
                clientChannel.Abort();
            }
        }
    }
}

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Threading;
using System.Collections.Generic;
using System.Diagnostics;

/// 

/// Summary description for JokeServer
/// 
public static class MOTDServer
{
    static Queue MessageQueue = new Queue();
    static Random rng = new Random();
    static Thread ProducerThread;

    static string[] Messages =
        {
            "A bird in the hand is worth two in the bush",
            "A rolling stone gathers no moss",
            "A penny saved is a penny earned",
            "I'd rather have a bottle in front of me than a frontal lobotomy",
            "When life hands you lemons, make lemonade"
        };

    private static void Init()
    {
        ProducerThread = new Thread(ProduceMessages);
        ProducerThread.Priority = ThreadPriority.Lowest;
        ProducerThread.Start();
    }


    public static string GetNextMessage()
    {
        if (ProducerThread == null)
            Init();

        string retval = null;

            Monitor.Enter(MessageQueue);
            while(MessageQueue.Count == 0)
                Monitor.Wait(MessageQueue);
            retval = MessageQueue.Dequeue();
            Monitor.Exit(MessageQueue);

        return retval;
    }

    static void ProduceMessages()
    {
        for (; ; )
        {
            if (MessageQueue.Count == 0)
            {
                Monitor.Enter(MessageQueue);
                MessageQueue.Enqueue(Messages[rng.Next(Messages.Length)]);
                Monitor.Pulse(MessageQueue);
                Monitor.Exit(MessageQueue);
            }

            Thread.Sleep(rng.Next(5000) + 2000);
            Debug.WriteLine("finished waiting");
        }
    }
}

    // define the delegate needed for async calls below
    delegate List GetQuoteDelegate(DateTime dt);

    // Use Async invocation to request the quotes in parallel
    List[] GetQuotes(DateTime dt)
    {
        ReservationServices reservationService = new ReservationServices();
        List[] retval = new List[3];

        List getQuoteDelegates = new List();

        getQuoteDelegates.Add(reservationService.GetAirlineQuotes);
        getQuoteDelegates.Add(reservationService.GetCarRentalQuotes);
        getQuoteDelegates.Add(reservationService.GetHotelQuotes);

        CountdownEvent cde = new CountdownEvent(3);

        for(int i=0; i<3; i++)
        {
            int localI = i;
            GetQuoteDelegate getQuoteDelegate = getQuoteDelegates[i];
            getQuoteDelegate.BeginInvoke(dt,
                iar => {
                    retval[localI] = (List)getQuoteDelegate.EndInvoke(iar);
                    cde.Signal();
                }, 
                null
            );
        }

        // wait for all to be finished
        cde.Wait();

        return retval;
    }

Material : tinyurl.com/89 sj qvn

Iterators and anonymous methods

- yield keyword - internal and external iterations - anonymous methods : for throwaway methods ...

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            foreach (int i in DivisibleBy(0, 50, 5))
            {
                Console.WriteLine(i);
            }
        }

        static IEnumerable DivisibleBy(int min, int max,int divisor) {
            for (int i = min; i < max; i++)
            {
                if (i % divisor == 0) {
                    yield return i;
                }
            }
        }

    }




    class X_Enumerable : IEnumerable { 

        private int min;
        private int max;
        private int divisor;

        public X_Enumerable(int min, int max, int divisor)
        {
            this.min = min;
            this.max = max;
            this.divisor = divisor;
        }
 
        public IEnumerator GetEnumerator() {
            return new X_Enumerator(min, max, divisor); 
        } 
    }

    class X_Enumerator : IEnumerator
    {
        int min;
        int max;
        int divisor;
        int current;

        public X_Enumerator(int min, int max,int divisor)
        {
            this.min=min;
            this.max = max;
            this.divisor = divisor;
        }

        public Object Current
        {
            get { return current; }
        }

        public bool MoveNext()
        {
            this.current++;
            while (current % divisor != 0) {
                this.current++;
                if (current == max) {
                    return false;
                }
            }
            return true;
        }

        public void Reset()
        {
            this.current=min;
        }

        public void Dispose()
        {
            throw new NotImplementedException();
        }
    }
 
}

LINQ to Objects

- anonymous types :

var p = new { Name = "Andy", Age = 21 };@@

using System;
using System.Collections.Generic;
using System.Text;

namespace LINQBase
{
    class Program
    {
        static void Main(string[] args)
        {
            var people = new List();
            people.Add(new Person { Name = "Nick", Height = 1.30m });
            people.Add(new Person { Name = "Jay", Height = 1.80m });
            people.Add(new Person { Name = "Bob", Height = 2.30m });

            foreach (var littlePerson in people.Where(p => p.Height < 2))
            {
                Console.WriteLine(littlePerson.Name);
            }
        }
    }


    public class Person
    {
        public decimal Height { get; set; }
        public string Name { get; set; }
    }

    public static class Utils {
        public static IEnumerable Where(this IEnumerable items, Predicate condition)
        {
            foreach (T item in items)
            {
                if (condition(item))
                    yield return item;
            }
        }
    }
}

LINQ to XML

  
    
    
      Jeffrey Richter
    
    .Net 2.0
    .Net General
    http://www.amazon.com/gp/product/0735621632/sr=8-1/qid=1141842947/ref=pd_bbs_1/103-3403410-7338268?_encoding=UTF8
    35.99
  
  
    
    
      Anonymous
    
    .Net 3.5
    Service Composition
    http://msdn2.microsoft.com/en-us/library/bb412181.aspx
    0.0
  
  
    
    
      Brian Noyes
    
    .Net 2.0
    Windows Forms
    http://www.amazon.com/Data-Binding-Windows-Forms-2-0/dp/032126892X/ref=pd_bxgy_b_img_b
    32.99
  
  
    
    
      Fritz Onion
      Keith Brown
    
    .Net 2.0
    Web Apps
    http://www.amazon.com/Essential-ASP-NET-2-0-Fritz-Onion/dp/0321237706/ref=pd_bbs_sr_1/103-2749730-3599818?ie=UTF8&s=books&qid=1176902837&sr=8-1
    36.99
  
  
    
    
      Fritz Onion
    
    .Net 2.0
    Web Apps
    http://www.amazon.com/Essential-ASP-NET-Examples-Fritz-Onion/dp/0201760401/ref=pd_bbs_sr_2/103-2749730-3599818?ie=UTF8&s=books&qid=1176902837&sr=8-2
    31.49
  
  
    
    
      Mark Michaelis
    
    .Net 2.0
    C# Language
    http://www.amazon.com/Essential-2-0-Microsoft-NET-Development/dp/0321150775/ref=pd_bxgy_b_text_b/102-4792916-8428135?ie=UTF8&qid=1174210886&sr=1-2
    37.79
  
  
    
    
      Chris Anderson
    
    .Net 3.0
    Presentation Foundation
    http://www.amazon.com/Essential-Presentation-Foundation-Microsoft-Development/dp/0321374479/ref=sr_1_1/002-9650384-5136050?ie=UTF8&s=books&qid=1188296520&sr=8-1
    31.49
  
  
    
    
      Dharma Shukla
      Bob Schmidt
    
    .Net 3.0
    Workflow Foundation
    http://www.amazon.com/Essential-Workflow-Foundation-Microsoft-Development/dp/0321399838/ref=pd_bbs_sr_1/102-1611469-3153757?ie=UTF8&s=books&qid=1192436658&sr=8-1
    31.49
  
  
    
    
      Michele Bustamante
    
    .Net 3.0
    Communication Foundation
    http://www.amazon.com/Learning-WCF-Hands-Michele-Bustamante/dp/0596101627/ref=pd_bbs_sr_1/103-2749730-3599818?ie=UTF8&s=books&qid=1176904112&sr=8-1
    29.69
  
  
    
    
      Fabrice Marguerie
      Steve Eichert
      Jim Wooley
    
    .Net 3.5
    LINQ
    http://www.amazon.com/LINQ-Action-Fabrice-Marguerie/dp/1933988169/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1202326210&sr=1-1
    29.69
  
  
    
    
      Juval Lowy
    
    .Net 2.0
    .Net General
    http://www.amazon.com/gp/product/0596102070/ref=pd_kar_gw_1/103-3403410-7338268?_encoding=UTF8&v=glance&n=283155
    29.67
  
  
    
    
      Juval Lowy
    
    .Net 3.0
    Communication Foundation
    http://www.amazon.com/Programming-WCF-Services-Juval-Lowy/dp/0596526997/ref=pd_bbs_sr_1/102-1611469-3153757?ie=UTF8&s=books&qid=1192436749&sr=8-1
    29.69
  
  
    
    
      K. Scott Allen
    
    .Net 3.0
    Workflow Foundation
    http://www.amazon.com/Programming-Windows-Workflow-Foundation-Techniques/dp/1904811213/ref=sr_1_1/102-1611469-3153757?ie=UTF8&s=books&qid=1192436585&sr=8-1
    44.99
  
  
    
    
      Brian Noyes
    
    .Net 2.0
    Windows Forms
    http://www.amazon.com/Smart-Client-Deployment-ClickOnce-Applications/dp/0321197690/ref=pd_bbs_sr_1/102-5394843-6848112?ie=UTF8&s=books&qid=1175345601&sr=8-1
    29.69
  
  
    
    
      Vittorio Bertocci
      Garrett Serack
      Caleb Baker
    
    .Net 3.0
    CardSpace
    http://www.amazon.com/Understanding-Windows-CardSpace-Introduction-Independent/dp/0321496841/ref=sr_1_1/102-1611469-3153757?ie=UTF8&s=books&qid=1192436821&sr=8-1
    32.84
  
  
    
    
      Chris Sells
      Michael Weinhardt
    
    .Net 2.0
    Windows Forms
    http://www.amazon.com/gp/product/0321267966/qid=1141845579/sr=1-1/ref=sr_1_1/103-3403410-7338268?s=books&v=glance&n=283155
    32.39
  
  
    
    
      Adam Nathan
    
    .Net 3.0
    Presentation Foundation
    http://www.amazon.com/Windows-Presentation-Foundation-Unleashed-WPF/dp/0672328917/ref=pd_bbs_sr_1/103-2749730-3599818?ie=UTF8&s=books&qid=1176903814&sr=8-1
    34.49
  

public class Book
    {
        // Book properties
        public string Category { get; set; }
        public string Topic { get; set; }
        public string Title { get; set; }
        public decimal Price { get; set; }
        public string[] Authors { get; set; }
        public string WebSite { get; set; }

        // Book description
        public override string ToString()
        {
            string output = string.Format("{0} by {1}",
                Title, string.Join(", ", this.Authors));
            output += string.Format("
{0}
{1}
{2}",
                Category, Topic, Price.ToString("c"));
            return output;
        }
    }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;

namespace LinqToXmlLab
{
    static class RssFeed
    {
        public static XElement GetBooksXml(string url)
        {
            XElement xml = XElement.Load(url); 
            return xml;
        }

        public static List GetBooks(XElement xml)
        {
            XNamespace ns = "http://develop.com";

            IEnumerable booksQuery = from b in xml.Elements(ns + "book") select
                new Book { Title = (string)b.Element(ns + "title"),
                           Category = (string)b.Element(ns + "category"),
                           Topic = (string)b.Element(ns+"topic"),
                           Price = (decimal)b.Element(ns + "price"),
                           WebSite = (string)b.Element(ns + "link"),
                           Authors = (from a in b.Element(ns + "authors").Elements(ns + "author") select (string)a).ToArray()
                };

            return booksQuery.ToList();
        }

        public static XElement GetFeedXml(List books) { 
            XElement xml = new XElement("rss", 
                new XAttribute("version", "2.0"), 
                new XElement("channel", 
                    new XElement("title", "Essential .Net Reading"), 
                    new XElement("link", "http://localhost:12345/books/"), 
                    new XElement("description", ".Net developer reading"), 
                    from b in books orderby b.Category, b.Topic, b.Title select new XElement(
                        "item", 
                        new XElement("title", b.Title), 
                        new XElement("link", b.WebSite), 
                        new XElement("description", b)))); 
            return xml; 
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;
using System.Xml.Linq;

namespace LinqToXmlLab
{
    class Program
    {
        static void Main(string[] args)
        {
            HttpListener listener = new HttpListener();
            listener.Prefixes.Add("http://localhost:12345/books/");
            listener.Start();
            Console.WriteLine("Rss Feed Service is running");
            Console.WriteLine("Press Ctrl+C to terminate ...");

            while (true)
            {
                HttpListenerContext ctx = listener.GetContext();
                using (StreamWriter writer = new StreamWriter(ctx.Response.OutputStream))
                {
                    // Load xml from file
                    string url = @"..\..\books.xml";
                    XElement booksXml = RssFeed.GetBooksXml(url);

                    // Get books list
                    List books = RssFeed.GetBooks(booksXml);

                    // Convert books list to xml
                    XElement feedXml = RssFeed.GetFeedXml(books);

                    // Send xml to the reponse stream
                    writer.Write(feedXml);
                }
            }
        }
    }
}

Annoying bind exception...
If it looks like :

java.net.BindException: Address already in use

Then you might start your inquiry with the following command :

Windows : netstat -nab

OSX / Unix : lsof -i :9000

And...

WTF, Firefox (might be Windows though) is responsible for the port occupation. Shut down Firefox, kill the annoying issue !

-> lsof == list open files -> man lsof

Dummy example in just one class :

Lire la suite

XAML, WPF and converters Write a stupid app that has 2 text boxes, each time a number is entered in the first, the second receives the double, and the first should as well reflect the second one if the second is changed.

Lire la suite

Today it is about getting familiar with the delegates and events programming paradigms (C# implementation of the observer pattern, Listeners in Java)

Lire la suite

I'm getting serious about C# and had a course today on the basics : - C# overview - Visual Studio - Projects and assemblies - Collections - Generics We were finally given 2 exercises.

Lire la suite

FileReader fr = new FileReader(fileLocation); // read a file

BufferedReader br = new BufferedReader(fr);

String tmp = br.readLine();

while (tmp != null) { content.append(tmp + "\n"); tmp = br.readLine(); } br.close();

Weather is quite bad here in Zürich but well, I don't mind too much as I'll be attending Jazoon, THE java dev conference in Europe. I'll be blogging mainly for my employer but I'll tweet a lot, stay tuned : http://twitter.com/#search?q=Jazoon

Right now, opening keynote by James Gosling ! Edit 12:10 James Gosling's keynote was excellent, presenting shocking numbers and funny projects, in a nutshell :

• 10 billions Java enabled devices in the world (yes billions)
• 15 millions downloads of the JRE Java Runtime Environment a week
• 6 millions Java developpers

Projects mentioned, built on Java (of course) :

• brazilian healthcare system
• hadron collider in Geneva
• eBay.com Orbitz.com
• the Oyster card (London tube pass system)
• www.lincvolt.com project transforming a 6000 pounds lincoln car into an electric car, power management done by Java o' course

Then James did a little demo of the 2 ground breaking features of Java EE6, annotated servlets and EJB injection in servlets. I knew already about it, but it remains extremely handy and simplifies the EE development a great deal !

The talk closed with a little Java FX note and the future of computers, heading to massively parrallel computing instead of increasing GHz on single cores.

Afternoon sessions i attended were "RIA, security broken by design" and "JSF and Ajax @ Credit Suisse", quite obvious for the second one !
The RIA session was mostly about demoing XSS attacks and why using a framework is a good idea to enhance the security, nothing much. On the other hand, the CS-Jsf and Ajax session by Micha Kiener was extremely interesting and will hopefully impact my daily work as of Q3 2009. (Wait a minute Q3, really?).

Jazoon updates are starting to pop all around the blogosphere, in french even...Great !

GDP France 2007 : 1892 Billions EUR^[1]
State budget France 2007 : 355 Billions EUR ^[2]

GDP world 2007 : 78 360 Billions USD^[3]
Average daily trading volume on the FX market : 4000 Billions USD^[4]
Average daily trading volume in NYSE : 87 Billions USD^[5]

Paulson plan : 700 Billions USD^[6]
USA federal budget : 2979 Billions USD^[7]

Pour donner suite à cet article.

D'un point de vue pragmatique, j'aurais plus comparé des frameworks dans un premier temps. Applet, par exemple n'en a pas à ma connaissance, il faudra tout programmer de A à Z, et comprendre les détails de la techno. Pour faire une RIA, ça va être long. Très long. Personne ne fait ça, c'est clair.

Ajax, à l'opposé dispose de très nombreux frameworks qui permettront d'aller directement à l'essentiel.

• lightweight, javascript uniquement (Dojo, Striptaculous)
  • plus de contrôle
  • indépendance entre les technos UI et serveur
  • nombreux widgets
  • API pour la communication avec le serveur
• end-to-end (.Net Ajax framework, IceFaces, Appcelerator)
  • pas de javascript
  • style de développement identique aux applis non Ajax (tags générant du HTML et du JS)
  • dépendance accrue entre les widgets et la techno serveur

Dans la mesure ou l'on parle d'un business model de développement en interne, les coûts vont être pour 0.2 dans le dev et 0.6 dans la maintenance (licences, serveurs etc sont probablement négligeables).

Avec la mobilité permanente des développeurs, investir dans une techno jeune et très marketée comme Ajax, c'est s'assurer une certaine perennité et des coûts de maintenance bas. Qui ne connait pas Ajax dans le principe...
A l'inverse, quel développeur veut marquer sur son cv "2008-2010 : développement d'applets".

Pour Flex, comme toute techno propriétaire, les ressources de dév et maintenance coûteront plus chers "par tête", mais seront probablement plus productives, de par l'intégration et la qualité de l'outillage.

Pour revenir au concret, mes récentes tentatives avec JSF puis iceFaces ont été bien accueillies par les développeurs (Ajax framework de .Net pour les Microsoft boys). Solutions maintenant éprouvées, légères, qui couvrent la majorité des besoins, simples à maintenir dans le sens ou elles sont standard.
Applets? Plusieurs legacy en ont, et c'est un véritable cauchemar en maintenance...
Allez un peu de recherche sur JavaFX maintenant !