How to Access RSS Feeds Using Entity Framework

Microsoft Entity Framework serves as an object-relational mapping framework for working with data represented as objects. Although Visual Studio offers the ADO.NET Entity Data Model wizard to automatically generate the Entity Model, this model-first approach may present challenges when your data source undergoes changes or when you require greater control over entity operations. In this article, we will delve into the code-first approach for accessing RSS feeds through the CData ADO.NET Provider, providing you with more flexibility and control.

1. Open Visual Studio and create a new Windows Form Application. This article uses a C# project with .NET 4.5.
2. Run the command 'Install-Package EntityFramework' in the Package Manger Console in Visual Studio to install the latest release of Entity Framework.

3. Modify the App.config file in the project to add a reference to the RSS Entity Framework 6 assembly and the connection string.

   You can connect to RSS and Atom feeds, as well as feeds with custom extensions. To connect to a feed, set the URL property. You can also access secure feeds. A variety of authentication mechanisms are supported. See the help documentation for details.

   <configuration> ... <connectionStrings> <add name="RSSContext" connectionString="Offline=False;URI=http://broadcastCorp/rss/;" providerName="System.Data.CData.RSS" /> </connectionStrings> <entityFramework> <providers> ... <provider invariantName="System.Data.CData.RSS" type="System.Data.CData.RSS.RSSProviderServices, System.Data.CData.RSS.Entities.EF6" /> </providers> <entityFramework> </configuration> </code>
4. Add a reference to System.Data.CData.RSS.Entities.EF6.dll, located in the lib -> 4.0 subfolder in the installation directory.
5. Build the project at this point to ensure everything is working correctly. Once that's done, you can start coding using Entity Framework.
6. Add a new .cs file to the project and add a class to it. This will be your database context, and it will extend the DbContext class. In the example, this class is named RSSContext. The following code example overrides the OnModelCreating method to make the following changes:
   • Remove PluralizingTableNameConvention from the ModelBuilder Conventions.
   • Remove requests to the MigrationHistory table.
   using System.Data.Entity; using System.Data.Entity.Infrastructure; using System.Data.Entity.ModelConfiguration.Conventions; class RSSContext : DbContext { public RSSContext() { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { // To remove the requests to the Migration History table Database.SetInitializer<RSSContext>(null); // To remove the plural names modelBuilder.Conventions.Remove<PluralizingTableNameConvention>(); } }
7. Create another .cs file and name it after the RSS entity you are retrieving, for example, Latest News. In this file, define both the Entity and the Entity Configuration, which will resemble the example below: using System.Data.Entity.ModelConfiguration; using System.ComponentModel.DataAnnotations.Schema; [System.ComponentModel.DataAnnotations.Schema.Table("Latest News")] public class Latest News { [System.ComponentModel.DataAnnotations.Key] public System.String Author { get; set; } public System.String Pubdate { get; set; } }
8. Now that you have created an entity, add the entity to your context class: public DbSet<Latest News> Latest News { set; get; }
9. With the context and entity finished, you are now ready to query the data in a separate class. For example: RSSContext context = new RSSContext(); context.Configuration.UseDatabaseNullSemantics = true; var query = from line in context.Latest News select line;