FSRepository - A New NuGet Package

UPDATED: NuGet Package Manager 1.1 (release today - 2/12/2011) now supports F#!

A new NuGet package is now available in the NuGet gallery called FSRepository. This package adds a few F# source files and assembly references to your F# project so that EFCodeFirst 0.8 can be used for data access.

What is NuGet?
If you haven't heard, "NuGet is a Visual Studio extension that makes it easy to install and update open source libraries and tools in Visual Studio. When you use NuGet to install a package, it copies the library files to your solution and automatically updates your project (add references, change config files, etc). If you remove a package, NuGet reverses whatever changes it made so that no clutter is left." (http://www.nuget.org/)

What is EFCodeFirst?
I first heard about EFCodeFirst in a blog post by Steve Sanderson. In that post he states "In case you’re wondering, EFCodeFirst is the new super-elegant version of Entity Framework that persists plain .NET objects to a relational database without any configuration fuss...".

How Do I Use FSRepository 0.4?
Support for F# projects was added to NuGet by David Fowler on 1/20/2011. Because this is such a recent addition, the version of the NuGet Package Manager on Visual Studio Gallery doesn't yet have this functionality. However, you can get the latest from http://nuget.codeplex.com/ to create a version of the visual studio extension that contains this functionality (or just wait for a few days/weeks until the next version is released on Visual Studio Gallery). If neither of these options work for you, shoot me an email and we can discuss alternatives.

Once a version of NuGet Package Manager that includes support for F# projects is installed, you can install the FSRepository 0.3 package by doing the following:

1. Create or open a F# project.
2. Open the Package Manager Console window (this can be found in Visual Studio 2010 under View -> Other Windows -> Package Manager Console).
3. In the Package Manager Console, type "Install-Package FSRepository":

4. Hit "Enter" and wait for several seconds until you see something like this:

As long as there were no errors, your F# project should now contain the new assembly references and F# source files.

You can find the files that were used to create this NuGet package on my GitHub.

New F# Empty Web Application (Silverlight) Template

There is a new F# Silverlight application template up on Visual Studio Gallery that generates an "empty" Silverlight solution. The generated solution provides the necessary structure to start F# Silverlight development, but does not include any sample code. While the previously provided F# Silverlight template (discussed at http://bloggemdano.blogspot.com/2010/08/f-silverlight-template.html) provides a nice example, it's not always useful if you have a need for an entirely different type of application.

The new F# Empty Web Application (Silverlight) template can be downloaded from the web or through the Online Templates feature of Visual Studio 2010.

Here are the steps: (Note: Visual Studio 2010 Professional (or above) is required to use this template.)

1. In Visual Studio 2010, navigate to File -> New and select Online Templates.
2. Search for "Daniel Mohl" or "F# Empty Web Application (Silverlight)":

As with most of the things posted on this blog, you can find the full source used to create this template on my GitHub site.

New F# ASP.NET MVC 3 Template on Visual Studio Gallery

There is a new F# ASP.NET MVC 3 project template on Visual Studio Gallery. This template is a version of the F# ASP.NET MVC 2 project template that has been migrated to ASP.NET MVC 3. ASP.NET MVC 3 has several cool new features. Check out http://haacked.com/archive/2011/01/13/aspnetmvc3-released.aspx and http://www.asp.net/mvc/mvc3 for more information.

To get started, do the following (Note: Visual Studio 2010 Professional (or above) is required to use these templates):

1. Install ASP.NET MVC 3. View http://www.asp.net/mvc/mvc3 for more information.
2. In Visual Studio 2010, go to File -> New and select Online Templates.
3. Search for Daniel Mohl or "F# and C# ASP.NET MVC3":

As usual, you can find the full solution used to create this template on my GitHub.

Side-by-Side Asynchronous Programming Example in F#, C#, and VB

I was pleased to hear the announcement at PDC2010 by Anders Hejlsberg that C# and VB will likely be following the lead of F# by including asynchronous programming support. As Don Syme states in his post on this topic "the proposed design of C# and VB asynchronous programming is pleasant and simple, and heavily inspired by the corresponding feature of F#". In this post I will provide a simple example in F#, C#, and VB. The provided example is based on an example from a post by Don entitled "Async and Parallel Design Patterns in F#: Parallelizing CPU and I/O Computations". This example is also very similar to those provided in a series of posts on this topic by Tomas Petricek. I strongly recommend reading Don's post as well as Tomas's series.

F#:

open System
open System.IO
open System.Net

let getHtml url printStrategy =
    async { let request =  WebRequest.Create(Uri url)
            use! response = request.AsyncGetResponse()
            use stream = response.GetResponseStream()
            use reader = new StreamReader(stream)
            let contents = reader.ReadToEnd()
            do printStrategy url contents
            return contents }
 
let sites = ["http://www.bing.com";
             "http://www.google.com";
             "http://www.yahoo.com";
             "http://msdn.microsoft.com/en-us/fsharp/default.aspx"]

let printStrategy url (contents:string) =  
    printfn "%s - HTML Length %d" url contents.Length

let sitesHtml = Async.Parallel [for site in sites -> getHtml site printStrategy]
                |> Async.RunSynchronously

do printfn "\r\nProcess Complete\r\nPress any key to continue"

do Console.ReadLine() |> ignore

C#:

using System;
using System.IO;
using System.Net;
using System.Threading.Tasks;
using System.Linq;

namespace CSharpAsync
{
    class Program
    {
        static async Task<string> GetHtml(string url, 
            Action<string, string> printStrategy)
        {
            var request = WebRequest.Create(new Uri(url));
            using (var response = await request.GetResponseAsync())
            {
                using (var stream = response.GetResponseStream())
                {
                    using (var reader = new StreamReader(stream))
                    {
                        var contents = reader.ReadToEnd();
                        printStrategy.Invoke(url, contents);
                        return contents;
                    }
                }
            }        
        }

        static async Task ProcessSites(string[] sites, 
            Action<string, string> printStrategy)
        {
            var sitesHtml = 
                await TaskEx.WhenAll(
                    sites.Select(site => GetHtml(site, printStrategy)));
            Console.WriteLine("\r\nProcess Complete\r\nPress any key to continue");
        }

        static void Main(string[] args)
        {
            var sites = new[] { "http://www.bing.com",
                            "http://www.google.com",
                            "http://www.yahoo.com",
                            "http://msdn.microsoft.com/en-us/fsharp/default.aspx" };

            Action<string, string> printStrategy =
                (url, contents) =>
                    Console.WriteLine("{0} - HTML Length {1}", url, contents.Length);
            
            ProcessSites(sites, printStrategy).Wait();

            Console.ReadLine();
        }
    }
}

VB:

Imports System
Imports System.IO
Imports System.Net
Imports System.Threading.Tasks
Imports System.Linq

Module Module1

    Async Function GetHtml(ByVal url As String, ByVal printStrategy As Action(Of String, String)) As Task(Of String)
        Dim request = WebRequest.Create(New Uri(url))
        Using response = Await request.GetResponseAsync()
            Using stream = response.GetResponseStream()
                Using reader = New StreamReader(stream)
                    Dim contents = reader.ReadToEnd()
                    printStrategy.Invoke(url, contents)
                    Return contents
                End Using
            End Using
        End Using
    End Function

    Async Function ProcessSites(ByVal sites As String(), ByVal printStrategy As Action(Of String, String)) As Task
        Dim sitesHtml = _
            Await TaskEx.WhenAll(sites.Select(Function(site) GetHtml(site, printStrategy)))
        Console.WriteLine("{0}Process Complete{0}Press any key to continue", _
            Environment.NewLine)
    End Function

    Sub Main()
        Dim sites = New String() {"http://www.bing.com", _
                "http://www.google.com", _
                "http://www.yahoo.com", _
                "http://msdn.microsoft.com/en-us/fsharp/default.aspx"}

        Dim printStrategy As Action(Of String, String) = _
            Sub(url, contents) Console.WriteLine("{0} - HTML Length {1}", url, contents.Length)
        ProcessSites(sites, printStrategy).Wait()
        Console.ReadLine()
    End Sub

End Module

Presentation: Getting Started with F# Web Development - Slides

Thanks to all who came out to the Nashville Web Dev user group meeting tonight. Here are the slides from the presentation.

Getting Started with F# Web Development

View more presentations from dmohl.

Speaking at the October Nashville Web Dev User Group Meeting

I will be speaking at the Nashville Web Dev Group next Thurs. (10/21/2010) at 6:30 PM.

Here is the description of the talk:

Many of the features provided by F# lend themselves well to web development. In this talk, we will quickly go over some of the basics of the F# language, then dive into four quick ways to get started developing web application in F#. By the end, we will have built an F# and C# Silverlight application, an F# only Silverlight application, an F# and C# ASP.NET MVC 2 web application, and a web application with a platform called WebSharper.

C# WP7 Panorama with Caliburn.Micro Template

In my last post, I announced a F# and C# WP7 Panorama with Caliburn.Micro template. That template generated some interest in having a similar C# only template. You can find the C# only version on Visual Studio Gallery or through the Online Templates feature of Visual Studio 2010.

Here are the steps:

1. Download and install the RTW release of the Windows Phone Developer Tools.
2. In Visual Studio 2010, navigate to File -> New and select Online Templates.
3. Search for "Daniel Mohl" or "C# WP7 with Caliburn.Micro":

The full source is available at http://github.com/dmohl/CSharpWP7PanoramaWithCaliburnMicro.