ThumNet

Because I wanted to learn programming in Adobe Flex I build a tool called airTranslate. It uses the Google Ajax Language API to translate the users input text to the chosen output language.

airTranslate features:

• Multi platform
• Auto detection of input language
• Drag and drop input text (with auto translation)
• Dock to tray icon (Windows only)
• Translate from clipboard (with auto translation)
• Auto store last chosen translation language
• Update notification

airTranslate is available at Google code: http://code.google.com/p/thumnet/downloads/list

The project is open source, and sources are available at http://code.google.com/p/thumnet/source/browse/#svn/trunk/Air. It is possible to request new functions and report issues through the Google code website.

To run Adobe AIR programs you need to download and install the Adobe AIR runtime

In my previous post I talked about the modifications I had made to the Pixeled WordPress theme.

Well about 2 months ago I send the creator of the Pixeled theme an email requesting him to read my blogpost about the changes I had made to his theme.
But since then I haven’t heard anything from him, so I decided to release the pixeled-multicolor theme myself.

Some screenshots:

Download Pixeled-Multicolor (release 20090701)

This post is about the session called C# 4.0 / The Future of C# given by Krishnan Subramanian.

First off let me start with a quick summary of main new feauture for the different versions of the C# that are released.

• C# 1.0, Managed code
• C# 2.0, Generics
• C# 3.0, Language Integrated Query, short LINQ
• C# 4.0, Dynamic programming

Some off the innovation for C# 4.0 are:

Dynamic Language Runtime
The new version of C# has a new type of object declaration, called dynamic. This looks a bit the var keyword. With the var keyword the compiler replaced the var with the object type on compile time, intellisense and code completion still was available in Visual Studio. With the new dynamic keyword the compiler doesn’t replace this and even more important the compiler can’t check for syntax error on a dynamic object. Intellisense and code complition are also not available for objects defined with dynamic.

Dynamic objects are losely typed instead of strongly.

After reading this you might think whats the use of this new DLR, in the following sample I’ll try to explain this. We have a simple C# class called Calculator, and use it like below.

Calculator calc = GetCalculator();
int sum = calc.Add(10, 20);

Now suppose the calculator class is not strongly typed, the code would like something like the following

object calc = GetCalculator();
Type calcType = calc.GetType();
object res = calcType.InvokeMember("Add", BindingFlags.InvokeMethod, null, new object[] { 10, 20 });
int sum = Convert.ToInt32(res);

With the new dynamic keyword in C# 4.0 it would simply be

dynamic calc = GetCalculator();
int sum = calc.Add(10, 20);

Optional Named Parameters
To show you the what this means take a look at the examples below.

In previous version of C# method overloads would be used.

public void Add(string lineOfText);
public void Add(string lineOfText, bool isError);
public void Add(string lineOfText, int repeat);
public void Add(string lineOfText, int repeat, bool isError);

With the new C# 4.0, the method declaration would like this

public void Add(string lineOfText, int repeat = 1, bool isError = false);

As you can see in the sample above, it’s now possible to specify default values for a method parameter. Some samples of how to use the Add method are:

Add("This is the line", repeat : 5);
Add(isError : true, lineOfText : "Another line of text");

For people using JavaScript this might look very familiar.

Another cewl new thing I saw at the demo, was the ability to interpret and compile a string of C# code at runtime. This functionality offers some great new possibilities. Again for the Javascript people reading this it’s like the eval function.

ADO.NET Dataservices is a new way to open your data to the web. It’s especially usefull in combination with a Rich Internet Client Application, such as a silverlight application or an AJAX application.

Dataservices is an implementation of WCF but has some restrictions to it.

• Dataservices makes use of the ATOM or the JSON format to transport the data, no other format is supported.
• The data is transported over the HTTP or HTTPS protocol and no other protocol is supported.
• Agarding to authentication you can´t use of the WCF authentication model. You are restricted to the standard authentication model ASP.NET offers you, Windows Authentication and Forms authentication.
• Dataservices has a REST based interface implementation, witch means a request to the service can only be done using REST.

Getting started with Dataservices.

To get started with Dataservices you first need to define a datasource. This datasource needs to implement IQueryable<T> for the Dataservices to use it. Two commonly used framework that implement this interface are LINQ2SQL and the Entity Framework. For use with Dataservices it’s prefered to use the EntityFramework. The  IQueryable<T>makes it possible for Dataservices to query the data but to be able to update insert and delete data the datasource also has to implement the IUpdateAble<T> interface, wich is implemented by the Entity Framework and not by LINQ2SQL.

Now the datasource is created the Dataservice has to be created. There is a new template for adding the dataservice in Visual Studio 2008 SP1.

After this has been added the dataservice needs to be pointed to the datasource, below is a sample of that where a NorthwindDataService  is Created which is pointed to a NorthwindDataContext. In the example the security is also set to read for all entities in the InitializeService method. The security can be set per entity and per method.

public class NorthwindDataService : WebDataService<NorthwindDataContext> {
InitializeService(IWebDataServiceConfiguration config)
{
config.SetResourceContainerAccessRule
("*", ResourceContainerRights.AllRead);
}
}

Dataservices is queried by REST, this can be tested in a browser by calling the service. In the examples below it’s shown how to query the service. For this example the url of the service is ‘http://localhost:5555/Bookmarks.svc’.

The url below request for the model of the data.

‘http://localhost:5555/Bookmarks.svc$metadata’

To request a list of all the bookmarks put the url below in the browser. Here the ‘/Bookmarks‘ refers to the entityset Bookmarks.

‘http://localhost:5555/Bookmarks.svc/Bookmarks’

As is shown in the metadata the key of Bookmark is the Id property. Every entity needs a key property. To get just 1 bookmark with id 1 the following url can be used:
‘http://localhost:5555/Bookmarks.svc/Bookmarks(1)’

It’s also possible to get a list of entities based upon a filter. For example get all bookmarks with Tags Devdays. This is done by using keywords, which always begin with a ´$´, in the querystring.

‘http://localhost:5555/Bookmarks.svc/Bookmarks?$filter=Tags eq Devdays’

For Silverlight applications it’s possible to query dataservices using LINQ2Dataservices so you don’t have to create these url’s yourself buth you can just use LINQ to create queries.

Much more information about ADO.NET Dataservices can be found on MSDN.

This post is about the session called What’s new in Silverlight 3 given by Mike Taulty.

A major disadvantage of RIA, Rich Internet Application, is that the state is of an application can not be recovered after the browser has been closed.

In Silverlight 3 there’s a solution for this problem. In SL3 you are now able to create a SL page. This in combination with the Frame and navigation Source make it possible to navigate through the same application based on the url.

The first part of the url is the path to the page on which the Silverlight page is located, for example http://localhost/SLapp.html.

After this the part of the url for the navigation within the application can be placed. This part must be preceded by a ‘#’, for example http://localhost/SLapp.html#SearchPage.xaml.

From webapplications we also now the querystring in the url for passing parameters to a site, this is also implemented in silverlight in the same way. The previously used url can then be formatted as followed http://localhost/SLapp.html#SearchPage.xaml?title=silverlight

More information about page navigation can be found at Mike Taulty’s blog.