Jack @ ASP.NET

ASP.NET MVC 2 is a framework for developing highly testable and maintainable Web applications by leveraging the Model-View-Controller (MVC) pattern. The framework encourages developers to maintain a clear separation of concerns among the responsibilities of the application – the UI logic using the view, user-input handling using the controller, and the domain logic using the model. ASP.NET MVC applications are easily testable using techniques such as test-driven development (TDD).
The installation package includes templates and tools for Visual Studio 2008 SP 1 to increase productivity when writing ASP.NET MVC applications. For example, the Add View dialog box takes advantage of customizable code generation (T4) templates to generate a view based on a model object. The default project template allows the developer to automatically hook up a unit-test project that is associated with the ASP.NET MVC application.
Because the ASP.NET MVC framework is built on ASP.NET 3.5 SP 1, developers can take advantage of existing ASP.NET features like authentication and authorization, profile settings, localization, and so on. Download it at: http://www.microsoft.com/downloads/details.aspx?FamilyID=7aba081a-19b9-44c4-a247-3882c8f749e3&displaylang=en

What is new:

• The new ASP.NET MVC 2 validation feature now performs model-validation instead of input-validation (this means that when you use model binding all model properties are validated instead of just validations on changed values of a model).  This behavior change was based on extensive feedback from the community.

• The new strongly-typed HTML input helpers now support lambda expressions which reference array or collection indexes.  This means you can now write code like Html.EditorFor(m=>m.Orders[i]) and have it correctly output an HTML <input> element whose “name” attribute contains the index (e.g. Orders[0] for the first element), and whose “value” contains the appropriate value.

• The new templated Html.EditorFor() and Html.DisplayFor() helper methods now auto-scaffold simple properties (and do not render complex sub-properties by default).  This makes it easier to generate automatic scaffolded forms.  I’ll be covering this support in a future blog post.

• The “id” attribute of client-script validation message elements is now cleaner.  With RC1 they had a form0_ prefix.  Now the id value is simply the input form element name postfixed with a validationMessage string (e.g. unitPrice_validationMessage).

• The Html.ValidationSummary() helper method now takes an optional boolean parameter which enables you to control whether only model-level validation messages are rendered by it, or whether property level validation messages are rendered as well.  This provides you with more UI customization options for how validation messages are displayed within your UI.

• The AccountController class created with the default ASP.NET MVC Web Application project template is cleaner.

• Visual Studio now includes scaffolding support for Delete action methods within Controllers, as well as Delete views (I always found it odd that the default T4 templates didn’t support this before).

• jQuery 1.4.1 is now included by default with new ASP.NET MVC 2 projects, along with a –vsdoc file that provides Visual Studio documentation intellisense for it.

• The RC2 release has some significant performance tuning improvements (for example: the lambda based strongly-typed HTML helpers are now much faster).

Can you explain the difference between an ADO.NET Dataset and an ADO Recordset?

• You can store many edits in a DataSet, and write them to the original data source in a single operation.
• Though the DataSet is universal, other objects in ADO.NET come in different versions for different data sources.
• There’s no concept of cursor types in a DataSet.

• A DataSet is designed to work without any continuing connection to the original data source.
• A DataSet can represent an entire relational database in memory, complete with tables, relations, and views.
• Data in a DataSet is bulk-loaded, rather than being loaded on demand.
• DataSets have no current record pointer You can use For Each loops to move through the data.

Why SEO?

Search engine optimization (SEO) is important for any publically facing web-site.  A large percentage of traffic to sites now comes from search engines, and improving the search relevancy of your site will lead to more user traffic to your site from search engine queries (which can directly or indirectly increase the revenue you make through your site).

IIS Search Engine Optimization (SEO) Toolkit

The SEO Toolkit helps you improve your Website’s relevance in search results by recommending how to make your new or existing site content and structure more search engine-friendly. It works on any Website on the Web. Best of all – it’s a small, lightweight free download!

ASP.NET 4 SEO Improvements

ASP.NET 4 includes a bunch of new runtime features that can help you to further optimize your site for SEO.  Some of these new features include:

• New Page.MetaKeywords and Page.MetaDescription properties
• New Response.RedirectPermanent() method
• New URL Routing support for ASP.NET Web Forms

You can use the above routes and methods for both ASP.NET Web Forms and ASP.NET MVC based URLs.

ASP.NET 4 includes a bunch of feature improvements that make it easier to build public facing sites that have great SEO.  When combined with the SEO Toolkit, you should be able to use these features to increase user traffic to your site – and hopefully increase the direct or indirect revenue you make from them.

A polyglot is a computer program or script written in a valid form of multiple programming languages, which performs the same operations or output independently of the programming language used to compile or interpret it.

Generally polyglots are written in a combination of C (which allows redefinition of tokens with a preprocessor) and a scripting programming language such as Lisp, Perl or sh.

For the past few years, many industry leaders were saying that developers needed to know multiple languages. They were right, because learning multiple languages (if done correctly) meant that you needed to learn different programming idioms: procedural programming, object oriented programming, functional programming, and so on.

But that’s painful. Why should I need to learn new syntax to use new idioms? Curly braces aren’t allowed in FP? semicolons aren’t permitted in dynamic languages?

Instead, why can’t a general purpose programming language support multiple programming idioms? C#, VB.NET, and C++ are starting to seriously support that. (Other languages may be doing this as well; I don’t know). All these languages have added (or are adding) lambda expressions which support functional programming concepts. (C++ has used Class Type Functors for this purpose for some time). C# is adding support for dynamic typing (as is VB.NET, in a more strict fashion than previously supported). Implicit typing is supported in C#, C++, and VB.NET as well.

This trend will continue as more and more developers want to use the best programming idiom for a particular task without learning a totally different syntax. Any programming language that calls itself a “general purpose language” will support multiple idioms.

The bad news is that only 52.7% of the users has .NET Framework 3.5 installed on their PCs, but as you can see from the table they become more and more very fast:

Unfortunately, because Visual Studio 2010 Beta 2 and ASP.NET MVC 2 Beta share components which are currently not in sync, running ASP.NET MVC 2 Beta on VS10 Beta 2 is not supported. Regarding Visual Studio 2010 and .NET 4 support, that is unfortunately not a feasible option. The most recent public release of VS2010 and .NET 4 is Beta 2. However, our internal builds of MVC 2 for VS2010 and .NET 4 depend on features that were available only after Beta 2. In other words, if we released what we have right now for VS2010 and .NET 4 then it wouldn’t even run.

The good news is that the Visual Studio 2010 Release Candidate will include a newer version of ASP.NET MVC 2. 

Highlights

As you might expect from a release candidate, most of the work focused on bug fixes and improvements to existing features. We also spent a lot of time on performance profiling and optimization.

Much of the focus on this release was in the client validation scripts. For example, the validation script was moved into its own file and can be included at the top or bottom of the page. Client validation also now supports globalization.

The other change related to validation is that the ValidationSummary now supports overloads where only model-level errors are displayed. This is useful if you are displaying validation messages inline next to each form field. Previously, these messages would be duplicated in the validation summary. With these new changes, you can have the summary display an overall validation message (ex. “There were errors in your form submission”) as well as a list of validation messages which don’t apply to a specific field.

What’s Next?

RTM of course! The RTM release of ASP.NET MVC will be included in the RTM release of Visual Studio 2010, which is slated for some time in March. The VS2008 version of ASP.NET MVC 2 might release earlier than that. We’re still working out those details.