RIA Services with Silverlight 4: Part I

What is .NET RIA Services?

Microsoft .NET RIA Services simplifies the traditional n-tier application pattern by bringing together the ASP.NET and Silverlight platforms. The RIA Services provides a pattern to write application logic that runs on the mid-tier and controls access to data for queries, changes and custom operations. It also provides end-to-end support for common tasks such as data validation, authentication and roles by integrating with Silverlight components on the client and ASP.NET on the mid-tier.

System Requirements: Visual Studio 2010 Ultimate, Silverlight 4 Beta

Let's start now...first of all make a new project using Silverlight Business Application using .NET Framework 4.



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Solutions Explorer will have layout like this.



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You can run the project and page will look like this.



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Click on Login.



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Click Register now.

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Now let's add ADO.NET Entity Data Model in Web Project.



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And choose data content.



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NOTE: After adding data model you have to build your web project this is mandatory. And after that add a new Domain Service Class in Services folder.



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Now you can see you data model in available data context...check you entity name and you can enable editing also.



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You service will have this code.

[EnableClientAccess()]
public class CustomersDomainService : LinqToEntitiesDomainService<NORTHWNDEntities1>
{

// TODO:
// Consider constraining the results of your query method. If you need additional input you can
// add parameters to this method or create additional query methods with different names.
// To support paging you will need to add ordering to the 'Customers' query.
public IQueryable<Customer> GetCustomers()
{
return this.ObjectContext.Customers;
}

public void InsertCustomer(Customer customer)
{
if ((customer.EntityState != EntityState.Detached))
{
this.ObjectContext.ObjectStateManager.ChangeObjectState(customer, EntityState.Added);
}
else
{
this.ObjectContext.Customers.AddObject(customer);
}
}

public void UpdateCustomer(Customer currentCustomer)
{
this.ObjectContext.Customers.AttachAsModified(currentCustomer, this.ChangeSet.GetOriginal(currentCustomer));
}

public void DeleteCustomer(Customer customer)
{
if ((customer.EntityState == EntityState.Detached))
{
this.ObjectContext.Customers.Attach(customer);
}
this.ObjectContext.Customers.DeleteObject(customer);
}
}

We are done with data model and service work here now we are moving on class work.

There are 2 ways to show entity data on page. First drag and drop data control on page and fill item source. Let see second one first.



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It adds two namespace on .xaml page.

xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"
xmlns:riaControls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.DomainServices"

and page adds following code.

<sdk:DataGrid AutoGenerateColumns="False" Height="200" ItemsSource="{Binding ElementName=customerDomainDataSource, Path=Data}" Margin="6,105,6,0" Name="customerDataGrid" RowDetailsVisibilityMode="VisibleWhenSelected" VerticalAlignment="Top">
<sdk:DataGrid.Columns>
<sdk:DataGridTextColumn x:Name="addressColumn" Binding="{Binding Path=Address}" Header="Address" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="cityColumn" Binding="{Binding Path=City}" Header="City" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="companyNameColumn" Binding="{Binding Path=CompanyName}" Header="Company Name" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="contactNameColumn" Binding="{Binding Path=ContactName}" Header="Contact Name" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="contactTitleColumn" Binding="{Binding Path=ContactTitle}" Header="Contact Title" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="countryColumn" Binding="{Binding Path=Country}" Header="Country" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="customerIDColumn" Binding="{Binding Path=CustomerID, Mode=OneWay}" Header="Customer ID" IsReadOnly="True" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="faxColumn" Binding="{Binding Path=Fax}" Header="Fax" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="phoneColumn" Binding="{Binding Path=Phone}" Header="Phone" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="postalCodeColumn" Binding="{Binding Path=PostalCode}" Header="Postal Code" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="regionColumn" Binding="{Binding Path=Region}" Header="Region" Width="SizeToHeader" />
</sdk:DataGrid.Columns>
</sdk:DataGrid>