ASP.NET 4.5 Web Pages 2

New features include the following:

   1. New and updated site templates.
   2. Adding server-side and client-side validation using the Validation helper.
   3. The ability to register scripts using an assets manager.
   4. Enabling logins from Facebook and other sites using OAuth and OpenID.
   5. Adding maps using the Maps helper.
   6. Running Web Pages applications side-by-side.
   7. Rendering pages for mobile devices.

   8. The configuration logic For MVC applications has been moved from Global.asax.cs to a set of static classes in the App_Start directory. Routes are     registered in RouteConfig.cs. Global MVC filters are registered in FilterConfig.cs. Bundling and minification configuration now lives in     BundleConfig.cs
  9. Publishing of the project come under the project from solution explorere, It is removed from the top menu. Now whole setting can be done by right     click on the project and set the publish settings.

 When you open a Visual Studio 2010 SP1 Web project for the first time in Visual Studio 11 Beta, the following properties are added to the project file:

    FileUpgradeFlags
    UpgradeBackupLocation
    OldToolsVersion
    VisualStudioVersion
    VSToolsPath
FileUpgradeFlags, UpgradeBackupLocation, and OldToolsVersion are used by the process that upgrades the project file. They have no impact on working with the project in Visual Studio 2010.

VisualStudioVersion is a new property used by MSBuild 4.5 that indicates the version of Visual Studio for the current project. Because this property didn’t exist in MSBuild 4.0 (the version of MSBuild that Visual Studio 2010 SP1 uses), we inject a default value into the project file.

Extract to user control

In large web pages, it can be a good idea to move individual pieces into user controls. This form of refactoring can help increase the readability of the page and can simplify the page structure. This is similiar to "Extract to metho" functionality which is available in 3.5 onwards. So "Extract to User Control" is available in .net 4.5.


The VSToolsPath property is used to determine the correct .targets file to import from the path represented by the MSBuildExtensionsPath32 setting.

There are also some changes related to Import elements. These changes are required in order to support compatibility between both versions of Visual Studio.

Configuration Changes in ASP.NET 4.5 Website Templates

The following changes have been made to the default Web.config file for site that are created using website templates in Visual Studio 2012 Release Candidate:

    In the <httpRuntime> element, the encoderType attribute is now set by default to use the AntiXSS types that were added to ASP.NET. For details, see AntiXSS Library.

    Also in the element, the requestValidationMode attribute is set to "4.5". This means that by default, request validation is configured to use deferred ("lazy") validation. For details, see New ASP.NET Request Validation Features.

    The <modules> element of the section does not contain a runAllManagedModulesForAllRequests attribute. (Its default value is false.) This means that if you are using a version of IIS 7 that has not been updated to SP1, you might have issues with routing in a new site. For more information, see Native Support in IIS 7 for ASP.NET Routing.

Changes in webforms 4.5

ASP.NET Web Forms Changes:

Strongly Typed Data Controls

In ASP.NET 4.5, Web Forms includes some improvements for working with data. The first improvement is strongly typed data controls. For Web Forms controls in previous versions of ASP.NET, we display a data-bound value using Eval and a data-binding expression:
eg: <asp:Repeater runat="server" ID="customers">
        <ItemTemplate>
            <li>
                First Name: <%# Eval("FirstName")%>

                Last Name: <%# Eval("LastName")%>

            </li>
        </ItemTemplate>
    </asp:Repeater>

For two-way data binding, we use Bind:
<asp:FormView runat="server" ID="editCustomer">
    <EditItemTemplate>
        <div>
            <asp:Label runat="server" AssociatedControlID="firstName">
                First Name:

            <asp:TextBox ID="firstName" runat="server"
                Text='<%#Bind("FirstName") %>' />
        </div>
<EditItemTemplate>
<asp:FormView>
        <div>
            <asp:Label runat="server" AssociatedControlID="lastName">
                First Name:</asp:Label>
            <asp:TextBox ID="lastName" runat="server">

                Text='<%#BindItem.LastName %>' />

At run time, these calls use reflection to read the value of the specified member and then display the result in the markup. This approach makes it easy to data bind against arbitrary, unshaped data.

To address this issue, ASP.NET 4.5 adds the ability to declare the data type of the data that a control is bound to. We do this using the new ItemType property. When we set this property, two new typed variables are available in the scope of data-binding expressions: Item and BindItem. Because the variables are strongly typed, we get the full benefits of the Visual Studio development experience.

The following example shows for the Item member:

<asp:Repeater runat="server" ID="customer" ModelType="WebApplication.Customer">
<itemTemplate>
    First Name: <%# Item.FirstName %><br/>
    Last Name: <%# Item.LastName %>
</itemTemplate>
</asp:Repeater>

For two way binding "BindItem" can be used in place of Item.

Model Binding

Model binding extends data binding in ASP.NET Web Forms controls to work with code-focused data access. It incorporates concepts from the
ObjectDataSource control and from model binding in ASP.NET MVC.
To configure a data control to use model binding to select data, you set the control's SelectMethod property to the name of a method in the page's code. The data control calls the method at the appropriate time in the page life cycle and automatically binds the returned data. There's no need to explicitly call the DataBind method.

In the following example, the GridView control is configured to use a method named GetCategories:

<asp:GridView ID="categoriesGrid" runat="server" ItemType="WebApplication1.Model.Category"
    SelectMethod="GetCategories" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="CategoryID" HeaderText="ID" />
        <asp:BoundField DataField="CategoryName" HeaderText="Name" />
        <asp:BoundField DataField="Description" HeaderText="Description" />
        <asp:TemplateField HeaderText="# of Products">
            <ItemTemplate><%# Item.Products.Count %></ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

Here  we have created "GetCategories" method in code behind file which is without any parameters and returning an IEnumerable or IQueryable object. If the new ItemType property is set (which enables strongly typed data-binding expressions, as explained under Strongly Typed Data Controls earlier), the generic versions of these interfaces should be returned — IEnumerable or IQueryable, with the T parameter matching the type of the ItemType property (for example, IQueryable).

Code behind method defination of "GetCategories":
public IQueryable
GetCategories()
{
    var db = new Northwind();
    return db.Categories.Include(c => c.Products);
 }

Any query can be placed on returned IEnumerable and IQueryable objects eg. sorting, paging etc.

Filtering by values from a control

Suppose we want to extend the example to let the user choose a filter value from a drop-down list. Add the following drop-down list to the markup and configure it to get its data from another method using the SelectMethod property:

<asp:Label runat="server" AssociatedControlID="categories"
    Text="Select a category to show products for: " />
<asp:DropDownList runat="server" ID="categories"
    SelectMethod="GetCategories" AppendDataBoundItems="true"
    DataTextField="CategoryName" DataValueField="CategoryID"
    AutoPostBack="true">
  <asp:ListItem Value="" Text="- all -" />
</asp:DropDownList>

<asp:GridView ID="productsGrid" runat="server" DataKeyNames="ProductID"
    AllowPaging="true" AllowSorting="true" AutoGenerateColumns="false"
    SelectMethod="GetProducts" >
    <Columns>
        <asp:BoundField DataField="ProductID" HeaderText="ID" />
        <asp:BoundField DataField="ProductName" HeaderText="Name"                  
             SortExpression="ProductName" />
        <asp:BoundField DataField="UnitPrice" HeaderText="Unit Price"
             SortExpression="UnitPrice" />
        <asp:BoundField DataField="UnitsInStock" HeaderText="# in Stock"
             SortExpression="UnitsInStock" />
    </Columns>
    <EmptyDataTemplate>
         No products matching the filter criteria were found
</asp:GridView>

In the page code, add the new select method for the drop-down list:

public IQueryable<Category>
GetCategories()
{
    return _db.Categories;
 }

Finally, update the GetProducts select method to take a new parameter that contains the ID of the selected category from the drop-down list:

public IQueryableGetProducts([QueryString("q")] string keyword,[Control("categories")] int? categoryId)
 {
    IQueryable query = _db.Products;
 
    if (!String.IsNullOrWhiteSpace(keyword))
    {
        query = query.Where(p => p.ProductName.Contains(keyword));
    }
    if (categoryId.HasValue && categoryId > 0)
    {
        query = query.Where(p => p.CategoryID == categoryId);
    }
    return query;
 }

Now when the page runs, users can select a category from the drop-down list, and the GridView control is automatically re-bound to show the filtered data. This is possible because model binding tracks the values of parameters for select methods and detects whether any parameter value has changed after a postback. If so, model binding forces the associated data control to re-bind to the data.

HTML Encoded Data-Binding Expressions

we can now HTML-encode the result of data-binding expressions. Add a colon (:) to the end of the <%# prefix that marks the data-binding expression:

<asp:TemplateField HeaderText="Name">
    <ItemTemplate><%#: Item.Products.Name %></ItemTemplate>
</asp:TemplateField>

Unobtrusive Validation

We can now configure the built-in validator controls to use unobtrusive JavaScript for client-side validation logic. This significantly reduces the amount of JavaScript rendered inline in the page markup and reduces the overall page size. Wecan configure unobtrusive JavaScript for validator controls in any of these ways:
Globally by adding the following setting to the element in the Web.config file:

<add name="ValidationSettings:UnobtrusiveValidationMode" value="WebForms" />

HTML5 Updates

Some improvements have been made to Web Forms server controls to take advantage of new features of HTML5:

    The TextMode property of the TextBox control has been updated to support the new HTML5 input types like email, datetime, and so on.
    The FileUpload control now supports multiple file uploads from browsers that support this HTML5 feature.
    Validator controls now support validating HTML5 input elements.
    New HTML5 elements that have attributes that represent a URL now support runat="server". As a result, we can use ASP.NET conventions in URL paths, like the ~ operator to represent the application root
 (for example, <video runat="server" src="~/myVideo.wmv" />).
    The UpdatePanel control has been fixed to support posting HTML5 input fields.
                Text='<%# Bind("LastName") %>' />
        </div>
        <asp:Button runat="server" CommandName="Update"/>
    </EditItemTemplate>
</asp:FormView>

New improvements in .net 4.5 framework

Asynchronously Reading and Writing HTTP Requests and Responses

ASP.NET 4 introduced the ability to read an HTTP request entity as a stream using the HttpRequest.GetBufferlessInputStream method. This method provided streaming access to the request entity. However, it executed synchronously, which tied up a thread for the duration of a request.
ASP.NET 4.5 supports the ability to read streams asynchronously on an HTTP request entity, and the ability to flush asynchronously. ASP.NET 4.5 also gives you the ability to double-buffer an HTTP request entity, which provides easier integration with downstream HTTP handlers such as .aspx page handlers and ASP.NET MVC controllers.

Improvements to HttpRequest handling

The Stream reference returned by ASP.NET 4.5 from HttpRequest.GetBufferlessInputStream supports both synchronous and asynchronous read methods. The Stream object returned from GetBufferlessInputStream now implements both the BeginRead and EndRead methods. The asynchronous Stream methods let you asynchronously read the request entity in chunks, while ASP.NET releases the current thread between each iteration of an asynchronous read loop.
ASP.NET 4.5 has also added a companion method for reading the request entity in a buffered way: HttpRequest.GetBufferedInputStream. This new overload works like GetBufferlessInputStream, supporting both synchronous and asynchronous reads. However, as it reads, GetBufferedInputStream also copies the entity bytes into ASP.NET internal buffers so that downstream modules and handlers can still access the request entity. For example, if some upstream code in the pipeline has already read the request entity using GetBufferedInputStream, you can still use HttpRequest.Form or HttpRequest.Files.

Asynchronously flushing a response

Sending responses to an HTTP client can take considerable time when the client is far away or has a low-bandwidth connection. Normally ASP.NET buffers the response bytes as they are created by an application. ASP.NET then performs a single send operation of the accrued buffers at the very end of request processing.
If the buffered response is large (for example, streaming a large file to a client), you must periodically call HttpResponse.Flush to send buffered output to the client and keep memory usage under control. However, because Flush is a synchronous call, iteratively calling Flush still consumes a thread for the duration of potentially long-running requests.
ASP.NET 4.5 adds support for performing flushes asynchronously using the BeginFlush and EndFlush methods of the HttpResponse class. Using these methods, you can create asynchronous modules and asynchronous handlers that incrementally send data to a client without tying up operating-system threads. In between BeginFlush and EndFlush calls, ASP.NET releases the current thread. This substantially reduces the total number of active threads that are needed in order to support long-running HTTP downloads.

More features:

Support for await and Task-Based Asynchronous Modules and Handlers

New ASP.NET Request Validation Features

By default, ASP.NET performs request validation — it examines requests to look for markup or script in fields, headers, cookies, and so on. If any is detected, ASP.NET throws an exception. This acts as a first line of defense against potential cross-site scripting attacks.
ASP.NET 4.5 makes it easy to selectively read unvalidated request data. ASP.NET 4.5 also integrates the popular AntiXSS library, which was formerly an external library.
Developers have frequently asked for the ability to selectively turn off request validation for their applications. For example, if your application is forum software, you might want to allow users to submit HTML-formatted forum posts and comments, but still make sure that request validation is checking everything else.
ASP.NET 4.5 introduces two features that make it easy for you to selectively work with unvalidated input: deferred ("lazy") request validation and access to unvalidated request data.

Deferred ("lazy") request validation

In ASP.NET 4.5, by default all request data is subject to request validation. However, you can configure the application to defer request validation until you actually access request data. (This is sometimes referred to as lazy request validation, based on terms like lazy loading for certain data scenarios.) You can configure the application to use deferred validation in the Web.config file by setting the requestValidationMode attribute to 4.5 in the httpRUntime element, as in the following example:

<httpRuntime requestValidationMode="4.5" ... />

AntiXSS Library

Due to the popularity of the Microsoft AntiXSS Library, ASP.NET 4.5 now incorporates core encoding routines from version 4.0 of that library.

To do this, add the following attribute to the Web.config file:

<httpRuntime ...
  encoderType="System.Web.Security.AntiXss.AntiXssEncoder,

System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />

When the encoderType attribute is set to use the AntiXssEncoder type, all output encoding in ASP.NET automatically uses the new encoding routines.

• Using multi-Core JIT compilation for faster startup

  If you want to disable this feature, make the following setting in the Web.config file:

  <configuration>
    
    <system.web>
     <compilation profileGuidedOptimizations="None"  />
  
       

• Tuning garbage collection to optimize for memory 

            To enable GC memory tuning, add the following setting to the Windows\Microsoft.NET\Framework  \v4.0.30319\aspnet.config file:

<configuration>
<!-- ... -->
  <runtime>
    <performanceScenario value="HighDensityWebHosting"  />