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European ASP.NET 4.5 Hosting - Amsterdam :: Model Binding with Dropdown List in ASP.NET 4.5

clock December 20, 2013 05:32 by author Administrator

ASP.NET 4.5 Preview introduces new model binding for  ASP.NET web forms. The concept of model binding was first introduced with ASP.NET MVC and now it has incorporated with ASP.NET Web Forms. You can easily perform any CURD operation with any sort of data controls using any data access technology like Entity Framework,  ADO.NET, LINQ to SQL Etc.  In this post I am going talk about how you can bind the data with ASP.NET DropdownList using new Model Binding features.

Let’s say we have a speaker database and we wants to bind the name of the speakers with the DropDownList.  First placed an ASP.NET Dropdown control with the page  and set the “DataTextField” and “DataValueField” properties.

We can set the  ddlName.DataSource to specifying the data source from the code behind and bind the data with dropdpwnlist, but  in this case from the code behind to providing the data source.

Now, instead of specifying the DataSource, we will be setting the Dropdownlists SelectMethod property to point a method GetSpeakerNames() within the code-behind file.

Select method is expected to return us result of type IQueryable<TYPE>. Here is GetSpeakerName() method is defined as follows.

So, Instead of specifying the data source we are specifying the SelectMethod, which return the IQueryable type of Speaker object. Run the application, you will find the names binded with dropdown list. Hope this helps !



European ASP.NET 4.5 Hosting - Amsterdam :: Tutorial Customize ASP.NET 4.5 Membership

clock December 17, 2013 10:29 by author Patrick

The ASP.NET MVC 4 Internet template adds some new, very useful features which are built on top of SimpleMembership. These changes add some great features, like a much simpler and extensible membership API and support for OAuth. However, the new account management features require SimpleMembership and won't work against existing ASP.NET Membership Providers. I'll start with a summary of top things you need to know, then dig into a lot more detail.

Summary:

  • SimpleMembership has been designed as a replacement for the previous ASP.NET Role and Membership provider system
  • SimpleMembership solves common problems developers ran into with the Membership provider system and was designed for modern user / membership / storage need
  • SimpleMembership integrates with the previous membership system, but you can't use a MembershipProvider with SimpleMembership
  • The new ASP.NET MVC 4 Internet application template AccountController requires SimpleMembership and is not compatible with previous MembershipProviders
  • You can continue to use existing ASP.NET Role and Membership providers in ASP.NET 4.5 and ASP.NET MVC 4 - just not with the ASP.NET MVC 4 AccountController
  • The existing ASP.NET Role and Membership provider system remains supported, as it is part of the ASP.NET core
  • ASP.NET 4.5 Web Forms does not use SimpleMembership; it implements OAuth on top of ASP.NET Membership
  • The ASP.NET Web Site Administration Tool (WSAT) is not compatible with SimpleMembership

The following is the result of a few conversations with Erik Porter (PM for ASP.NET MVC) to make sure I had some the overall details straight, combined with a lot of time digging around in ILSpy and Visual Studio's assembly browsing tools.

SimpleMembership: The future of membership for ASP.NET
The ASP.NET Membership system was introduced with ASP.NET 2.0 back in 2005. It was designed to solve common site membership requirements at the time, which generally involved username / password based registration and profile storage in SQL Server. It was designed with a few extensibility mechanisms - notably a provider system (which allowed you override some specifics like backing storage) and the ability to store additional profile information (although the additional  profile information was packed into a single column which usually required access through the API). While it's sometimes frustrating to work with, it's held up for seven years - probably since it handles the main use case (username / password based membership in a SQL Server database) smoothly and can be adapted to most other needs (again, often frustrating, but it can work).

The ASP.NET Web Pages and WebMatrix efforts allowed the team an opportunity to take a new look at a lot of things - e.g. the Razor syntax started with ASP.NET Web Pages, not ASP.NET MVC. The ASP.NET Web Pages team designed SimpleMembership to (wait for it) simplify the task of dealing with membership. As Matthew Osborn said in his post Using SimpleMembership With ASP.NET WebPages:
With the introduction of ASP.NET WebPages and the WebMatrix stack our team has really be focusing on making things simpler for the developer. Based on a lot of customer feedback one of the areas that we wanted to improve was the built in security in ASP.NET. So with this release we took that time to create a new built in (and default for ASP.NET WebPages) security provider. I say provider because the new stuff is still built on the existing ASP.NET framework. So what do we call this new hotness that we have created? Well, none other than SimpleMembership. SimpleMembership is an umbrella term for both SimpleMembership and SimpleRoles.

Part of simplifying membership involved fixing some common problems with ASP.NET Membership.

Problems with ASP.NET Membership
ASP.NET Membership was very obviously designed around a set of assumptions:

  • Users and user information would most likely be stored in a full SQL Server database or in Active Directory
  • User and profile information would be optimized around a set of common attributes (UserName, Password, IsApproved, CreationDate, Comment, Role membership...) and other user profile information would be accessed through a profile provider

Some problems fall out of these assumptions.
Requires Full SQL Server for default case
The default, and most fully featured providers ASP.NET Membership providers (SQL Membership Provider, SQL Role Provider, SQL Profile Provider) require full SQL Server. They depend on stored procedure support, and they rely on SQL Server cache dependencies, they depend on agents for clean up and maintenance. So the main SQL Server based providers don't work well on SQL Server CE, won't work out of the box on SQL Azure, etc.

Custom Membership Providers have to work with a SQL-Server-centric API
If you want to work with another database or other membership storage system, you need to to inherit from the provider base classes and override a bunch of methods which are tightly focused on storing a MembershipUser in a relational database. It can be done (and you can often find pretty good ones that have already been written), but it's a good amount of work and often leaves you with ugly code that has a bunch of System.NotImplementedException fun since there are a lot of methods that just don't apply.

Designed around a specific view of users, roles and profilesThe existing providers are focused on traditional membership - a user has a username and a password, some specific roles on the site (e.g. administrator, premium user), and may have some additional "nice to have" optional information that can be accessed via an API in your application.
This doesn't fit well with some modern usage patterns:

  • In OAuth and OpenID, the user doesn't have a password
  • Often these kinds of scenarios map better to user claims or rights instead of monolithic user roles
  • For many sites, profile or other non-traditional information is very important and needs to come from somewhere other than an API call that maps to a database blob

What would work a lot better here is a system in which you were able to define your users, rights, and other attributes however you wanted and the membership system worked with your model - not the other way around.

Requires specific schema, overflow in blob columns


Update: This schema has been improved a lot with Universal Providers. The views and stored procedures have been removed, and the tables are simplified.

SimpleMembership as a better membership system
As you might have guessed, SimpleMembership was designed to address the above problems.

Then we point SimpleMemberhip at that table with a one-liner:
WebSecurity.InitializeDatabaseFile("SecurityDemo.sdf", "Users", "UserID", "Username", true);

Broaden database support to the whole SQL Server family
While SimpleMembership is not database agnostic, it works across the SQL Server family. It continues to support full SQL Server, but it also works with SQL Azure, SQL Server CE, SQL Server Express, and LocalDB. Everything's implemented as SQL calls rather than requiring stored procedures, views, agents, and change notifications.

Note that SimpleMembership still requires some flavor of SQL Server - it won't work with MySQL, NoSQL databases, etc. You can take a look at the code in WebMatrix.WebData.dll using a tool like ILSpy if you'd like to see why - there are places where SQL Server specific SQL statements are being executed, especially when creating and initializing tables. It seems like you might be able to work with another database if you created the tables separately, but I haven't tried it and it's not supported at this point.

Easy to with Entity Framework Code First
The problem with with ASP.NET Membership's system for storing additional account information is that it's the gate keeper. That means you're stuck with its schema and accessing profile information through its API.

SimpleMembership flips that around by allowing you to use any table as a user store. That means you're in control of the user profile information, and you can access it however you'd like - it's just data. Let's look at a practical based on the AccountModel.cs class in an ASP.NET MVC 4 Internet project. Here I'm adding a Birthday property to the UserProfile class.

How SimpleMembership integrates with ASP.NET MembershipOkay, enough sales pitch (and hopefully background) on why things have changed. How does this affect you? Let's start with a diagram to show the relationship (note: I've simplified by removing a few classes to show the important relationships):
So SimpleMembershipProvider is an implementaiton of an ExtendedMembershipProvider, which inherits from MembershipProvider and adds some other account / OAuth related things. Here's what ExtendedMembershipProvider adds to MembershipProvider:

Membership in the ASP.NET 4.5 project template
ASP.NET 4.5 Web Forms took a different approach which builds off ASP.NET Membership. Instead of using the WebMatrix security assemblies, Web Forms uses Microsoft.AspNet.Membership.OpenAuth assembly. I'm no expert on this, but from a bit of time in ILSpy and Visual Studio's (very pretty) dependency graphs, this uses a Membership Adapter to save OAuth data into an EF managed database while still running on top of ASP.NET Membership.

How does this fit in with Universal Providers (System.Web.Providers)?
Just to summarize:

  • Universal Providers are intended for cases where you have an existing ASP.NET Membership Provider and you want to use it with another SQL Server database backend (other than SQL Server). It doesn't require agents to handle expired session cleanup and other background tasks, it piggybacks these tasks on other calls.
  • Universal Providers are not really, strictly speaking, universal - at least to my way of thinking. They only work with databases in the SQL Server family.
  • Universal Providers do not work with Simple Membership.
  • The Universal Providers packages include some web config transforms which you would normally want when you're using them.



European ASP.NET 4.5 Hosting :: Key HTML Editor Features ASP.NET 4.5

clock December 12, 2013 07:32 by author Patrick

We will be go through the key HTML editor features introduced in ASP.NET 4.5. Automatic Renaming of the matching tag. In ASP.NET 4.5, we have a very productive feature where matching tags are automatically renamed when we change the opening tag.

Consider the following code in HTML side

Now in earlier versions of ASP.NET if I had to make a change in the starting tag then I had to manually update the end tag too. However, with ASP.NET 4.5, you will see that if you update the starting tag then the end tag will also update automatically.

Please see the following image for more details.

Extract to User Control

The ASP.NET 4.5 desiners have developed a very unique and productive feature where at any point of time, we can change code present in a web form to a user control.
Consider I have a web form containing TextBoxes for userName and Password for authentication. While working on this page, we found that we need this user name and password authentication in various modules of the project.


With this said, ASP.NET 4.5 provides us the great feature where we must simply select the code and we can change that selected code to a User Control; see:

Smart Task in HTML Editor

One of the productive features added to ASP.NET a few years back was the addition of a smart task. On the click of the smart available on the control, you can accomplish some of the common tasks on that control.


Now with ASP.NET 4.5, we have the same feature while working on the HTML side. Hence, we don't need to go to design mode to use this feature.

If you click on the line present under "a" , this would open up the smart task for that control.

You will see that you can perform all the common tasks for that control.

Code Snippets in HTML

With ASP.NET 4.5, we have code snippets available in HTML. If you want to add audio or video to you page then you simply must type video on HTML and press TAB twice. You will see that full audio / video control is available, mentioning all the common properties.

Event Handler generation

Before the release of ASP.NET 4.5, if we must create any event handler for any control then we either must double-click on that control, that will generate an event for that control or define the event in the properties of that control. However, with ASP.NET 4.56 we have a new property added in the control, where we can generate an event for the control at the HTML side and we don't need to switch to design mode.

Clicking on "Create New Event" will create a default event for that control; however we can provide any name of that event and you would see that Visual Studio will then automatically generate the appropriate server side event handler within your code behind file for you.

Hope this article of mine has been helpful in giving some knowledge of the new features of ASP.NET 4.5.



European ASP.NET 4.5 Hosting - HostForLIFE.eu :: Friendly URLs in ASP.NET 4.5 Web Forms

clock November 27, 2013 06:10 by author Scott

In the recent update of ASP.NET, Microsoft released support for Friendly URLs in ASP.NET Web Forms. It is based on the concept of Routing. But, we don’t need to deal with route table to manually add the routes to be mapped. URLs of the site will be automatically made friendly after invoking when the application starts.

To get started using the Friendly URLs, we need to install the NuGet Package Microsoft.AspNet.FriendlyUrls. The package is not stable yet, so we need to search it in pre-release packages.

This package adds following files to the web application:

  • Microsoft.AspNet.FriendlyUrls assembly – Contains required set of classes and interfaces
  • Site.Mobile.Master – Master page for mobile devices
  • ViewSwitcher.ascx – A user control that can be used to switch views from desktop view to Mobile view and vice versa

Once Visual Studio finishes installing the NuGet package, a read me file will be popped up. This file contains the steps to be followed to enable Friendly URLs on your site. All you have to do is, call the EnableFriendlyUrls extension method of RouteTable in RegisterRoutes method of RouteConfig class. This method is defined in Microsoft.AspNet.FriendlyUrls namespace.

routes.EnableFriendlyUrls();

And make sure that the RegisterRoutes method is called in Application_Start event of Global.asax:

RouteConfig.RegisterRoutes(RouteTable.Routes);

Now run the application and check URL on the address bar of your browser.

And the magic happened! As we see here, the URL doesn’t contain extension of the page.

Note: You don’t have to install NuGet package and apply the above settings if you have installed ASP.NET and Web Tools 2012.2. These changes are built into the ASP.NET web application template in the new template.

If you are using default ASP.NET 4.5 Web application template, you can invoke the Login (which resides in Account folder) page using:

http://mysite/Account/Login

You can link any page that resides in a folder using the same convention.

Hyperlinks to the pages can be replaced with the friendly convention.

<a id="loginLink" runat="server" href="~/Account/Login">Log in</a>

Data can be passed to a page using segments. Href method of FriendlyUrl class can be used for this purpose:

<a href="<%: FriendlyUrl.Href("~/BookDetails","AspNet") %>">ASP.NET</a>

This hyperlink forms the following URL:

http://mysite/BookDetails/AspNet

This data can be displayed on the page in any mark-up element. To display the topic of book sent through the above URL in a span element, we have to get the value from the segment as shown below:

<span><%: Request.GetFriendlyUrlSegments()[0].ToString() %></span>

Also, this value can be passed as a parameter to a method used for Model Binding as shown below:

public IQueryable<Customer> GetBooks([FriendlyUrlSegments]string topic)
{
    var selectedBooks = context.Books.Where(c => c.BookName.Contains(topic));
    return selectedBooks;
}

Remember that, if you are navigating to the page ListBooks.aspx with following URL,

http://mysite/ListBooks/Book/AspNet

then the parameter marked with FriendlyUrlSegments will hold the value Book/AspNet. So, this should be handled with care.



European ASP.NET 4.5 Hosting - Amsterdam :: Windows Identity Foundation 4.5 in NET 4.5

clock October 16, 2013 12:03 by author Scott

Windows Identity Foundation 4.5 (WIF) is a framework for building identity-aware and more specifically claims-aware applications. It furthermore provides an abstraction  to the underlying protocols (ex: WS-Trust, WS-Federation, etc …) and therefore encapsulates and standardizes application security.

Developers do not need to know how to exactly implement and use those protocols anymore. Instead they may use API calls to the WIF Toolkit for implementing secure applications, thus resulting in applications which are loosely coupled to their security implementations. Tokens issued from a large scale of different security providers (including  ADFS 2.0, ACS and custom Security Token Services) can be handled.

The default configuration and behavior works great and with ease you will be able to implement it in no time. But the best of all : the WIF Toolkit is highly customizable. You may completely override and customize the default behavior on some or on all the step of the process (Protocol Module, Session Module, Claims Authorization Module, Token, STS, etc..).

WIF in its first version (1.0) is available as a runtime and as an external SDK for .NET 3.5 and .NET 4.0. You have to install it separately for being able to using it in your applications. The WIF Training Kit contains everything necessary to start with claims based security (explication, tutorials, examples, etc…).

WIF 4.5 and .NET 4.5

So what’s new in WIF 4.5 ? Well first of all WIF is now part of the .NET framework. You do not need to install it manually anymore. It is shipped and installed with .NET 4.5, which means that it is now an integral part of the framework ! Most of the classes and methods are now part of Mscorlib.dll !

Also it is now much easier and straightforward use WIF and to query for claims. Let me show this in the following example.

Create a new web application, right click on your project in the Solution Explorer and select "Identity and Access…” from the list.

You will see a new configuration wizard, which will guide you through the process of setting up a STS reference. You may either use a development STS, a business provider based on ADFS2 or Windows Azure Access Control Service (ACS).

For the example I use the development STS :

You may now run your web application and the development STS gets started automatically. When you see the little icon in the tray area you know that everything working correctly.

Now lets see how to query for a claim by using the ClaimsPrincipal in the System.Security.Claims namespace and calling its FindFirst(…) method.

Where you had to write at least 3 lines of code and do casting operations in WIF 1.0, you now have everything in a single line ! Much easier to implement, to understand, to maintain and also to extend !

Note that there are a variety of other utility methods to aid you in working with claims (FindAll, FindFirst, HasClaim, etc…) and that you have access to almost everything just by using the  ClaimsPrincipal.

Another improvement is the seamless integration of WCF 4.5 and WIF 4.5. You now can use both together much more easily. Custom service host factories or federation behaviors are not needed anymore. This can be achieved via the useIdentityConfiguration switch.

WIF 4.5 and WebFarms

Great news for all developers using WIF in a WebFarms environment. With .NET 4.5 it is finally possible to use WIF without implementing complicated and time consuming workarounds to encrypt your WIF cookies with a single encryption key.

You just configure a new MachineSessionSecurityHandler by setting it in your Web.config file and it will work without any further changes ! This has even been added to the wizard as a checkbox! How easy is that compared to the old way of resolving this problem !

WIF 4.5 and Windows Server 2012

Windows Server 2012 Domain Controllers are going to support the claims based model and provide extra claims via Kerberos (User Claims and Device Claims), which you may then query for within your WIF 4.5 implementations. This is actually a quite interesting feature.

WIF 4.5 and Visual Studio 2012

The integration of WIF tools has been completely re-designed, as you saw in my quick example above. This has been done to simplify the whole process and to render it much more comprehensive. So it is now easier to understand with less steps and quicker configuration.

As you saw above the new tools contain a local development STS which simulates a real STS (comparable to the development fabric within the Windows Azure SDK). The development STS is by the way completely configurable (Token format, port, test claims, etc..).

Furthermore, the WIF 4.5 tools and all samples are now distributed as VSIX via the Visual Studio Extensions Gallery.

Conclusion

As you can see WIF 4.5 has been greatly enhanced and industrialized. It will become the the primary choice when working with application security. Come on and give it at try,  test all these new features by downloading the Windows Identity Foundation Tools for Visual Studio 2012 RC.



European ASP.NET 4.5 Hosting - Amsterdam :: Web API. VB.NET Example ASP.NET 4.5

clock August 15, 2013 08:55 by author Scott

The new feature that appeals to me is the new “Web API” which eases the development of REST and AJAX APIs (API is the new Microsoft jargon for a web service!)

Wanting to have a play with this new feature, I fired up Visual Studio Express 2012 and created a standard web application in vb.net. Although many examples on the web are showing the Web API with MVC, it can be used in any .net application.

 

Using the new “Web API”  requires two parts.

1. Setup the controller class that will perform the logic.

2. Setup up route tables in your global.asax.vb file, to correctly “route” the client request to the correct controller class.

So down to code. The examples below assume a GET request to the Web API Server.

1. Create a standard web application, remembering to specify .net 4.5 as the target framework.

2. Create a new folder within the application called “Controllers”. See Picture below.

3. Within this folder, create a new “Web API Controller Class”, by right clicking on the Controllers folder and clicking Add. Then choose “Web API Controller Class” from the list as shown below

4. When naming this new controller class, remember to leave the word controller at the end of the name, otherwise the routing won’t work! As you can see below, I called my class VenueApiController.vb

5. When you open this new class, you will see some get, post,delete functions already filled in. I just created new functions to suit my client data requirements.

The sample data that I am using is for a project we have been working on call nejola.com. This allows local businesses to “push” their deals to Android smartphone users in the locality.

We have some test data in the SQL Server, so used this to try the Web API out.

The first function that I created returned a full list of the test venues available. I named this function GetVenues. No search data was needed to be passed to the function and I wanted the result fetched as a dataset to the client. The beauty of the “Web API” is the data is then presented to the client depending upon the headers of the calling client. For example an ajax call will return the data in a json format

Public Function GetVenues() As DataSet

Try

                Using sqlConn As New
SqlConnection(ConfigurationManager.ConnectionStrings("DefaultConnection").ConnectionString)
                    Dim sqlComm As SqlCommand = New SqlCommand
                    sqlComm.Connection = sqlConn
                    sqlComm.CommandText = "SELECT * From df_Locations"
                    Dim sqlDataAdapt As SqlDataAdapter = New SqlDataAdapter(sqlComm)
                    Dim ds As DataSet = New DataSet
                    sqlDataAdapt.Fill(ds)
                    sqlDataAdapt.Dispose() : sqlComm.Dispose() : sqlConn.Close() : sqlConn.Dispose()
                    ds.DataSetName = "VenueData"
                    ds.Tables(0).TableName = "exgVenuesData"
                    Return ds
                End Using

            Catch ex As Exception

                Return Nothing

            End Try

And that’s it for the data logic ! Nothing too fancy here, just perform some SQL on the SQL server and return the dataset. I would normally call a stored procedure for but this purpose used the commandtext

The function below requires a parameter to be passed, in this case the town name as a string.

Public Function GetVenueByTown(ByVal town As String) As DataSet
Dim sqlConn As SqlConnection = New SqlConnection("Connection info here")
sqlConn.Open()
Dim sqlComm As SqlCommand = New SqlCommand()
sqlComm.Connection = sqlConn
sqlComm.CommandText = "SELECT * From df_Locations WHERE VenueTown = '" & town & "'"
Dim sqlDataAdapt As SqlDataAdapter = New SqlDataAdapter(sqlComm)
Dim ds As DataSet = New DataSet
sqlDataAdapt.Fill(ds)
sqlDataAdapt.Dispose() : sqlComm.Dispose() : sqlConn.Close() : sqlConn.Dispose()
ds.DataSetName = "VenueTownData"
ds.Tables(0).TableName = "EXGTownData"
Return ds
End Function

Now that we have two working functions within the API Class, we need to add routing to call the functions. Users Of Microsoft MVC should be aware of routing and controllers, however for VB.net users this is new with .net 4.5

What the routing and controllers allows us to do is present the URL’s called by the clients  in a nice format. For example to call the GetVenues function above, the client can call :

http://domain.com/venues

To call the GetVenueByTown function and pass the town parameter the client can use :

http://domain.com/venues/town/townname

Ok, so now we need to setup the routing for this to work !

1. Open the global.asax.vb file and look for the sub

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)

End sub

2. At the top of the page add :

Imports System.Web.Routing

Imports System.Web.Http

3. Here is the code for the GetVenues Function which is the default function called. Add this to the Application_Start Sub.

RouteTable.Routes.MapHttpRoute(name:="Venue", _
routeTemplate:="venues", _
defaults:=New With {.symbol = RouteParameter.Optional, .controller = "VenueApi"})

To break down the above, here is what is happening. This example is the default call, with no parameters being passed to the function.

name:=”Venue” –> This is the name given to this routetable. Each routetable has a different name.

routeTemplate:=”venues” –> This is the actual name that the client will call. In this example http://domain.com/venues.

.controller = “VenueApi” –> This MUST match the name that you gave your controller class without the controller part.

The route code to call the GetVenueByTown function that requires a town parameter to be passed is as follows :

RouteTable.Routes.MapHttpRoute(name:="VenueTowns", _
routeTemplate:="venues/town/{town}", _
defaults:=New With {.symbol = RouteParameter.Optional, .controller = "VenueApi"})

Again a break down of the code is as follows :

name:=”VenueTowns” –> Unique name of the routetable.

routeTemplate:=”venues/town/{town}” –> This is the path that will be entered by the client to get to the correct function. Note we have added the /town/ path and the parameter {town}. This parameter name must match that of the function otherwise the routing won’t work correctly.

controller = “VenueApi” –> This is the same as before and is the controller class without the controller part.



About HostForLIFE.eu

HostForLIFE.eu is European Windows Hosting Provider which focuses on Windows Platform only. We deliver on-demand hosting solutions including Shared hosting, Reseller Hosting, Cloud Hosting, Dedicated Servers, and IT as a Service for companies of all sizes.

We have offered the latest Windows 2012 Hosting, ASP.NET 4.5 Hosting, ASP.NET MVC 4 Hosting, ASP.NET MVC 5 Hosting and SQL 2014 Hosting.


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