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Table 9-4 lists the useful parts of the SDK classes, along with some descriptions, circles, and arrows and a paragraph on the back of each one explaining what each one is to be used as evidence against us (every technical book worth its salt has to have at least one Arlo Guthrie reference there s mine).

Figure 12-16. Policy options 3. Right-click the Version 1.0 node and select Add New Rule. 4. Name your new rule 12Rule. In the pane to the right, you ll find that you ve been provided a bit of an editor where you can build your rule, as shown in Figure 12-17. It s pretty lightweight, which is perfect for the amount of work that is required.

Child objects are inserted, updated, or deleted as part of the process of updating a root parent object. To support this concept, child collections implement an internal method named Update(). Child objects within a collection implement internal methods, named Insert(), Update(), and DeleteSelf(), that can be called by the collection during the update process. It is helpful for related root, child, and child collection classes to be placed in the same project (assembly) so that they can use internal scope in this manner. The sequence of events to add, edit, or delete a child object is as follows: 1. The root object s DataPortal_XYZ method calls the child collection s Update() method; the parent object is passed as a parameter so that child objects can use root object property values as needed (such as for foreign key values). 2. The child collection s Update() method loops through all the deleted child objects in the collection, calling each deleted object s DeleteSelf() method. 3. The child collection s Update() method loops through all its active child objects, calling each child object s Insert() or Update() method based on the child object s IsNew property value. 4. At this point, all the child object data has been inserted, updated, or deleted as required.

This doesn t sound that hard, until you read the fine print in the documentation and start using the interface and then discover the even finer print that isn t actually in the documentation at all.

In today s world, an object-oriented application must be designed to work in a variety of physical configurations. Even the term application has become increasingly blurry due to all the hype around service-oriented architecture (SOA). If you aren t careful, you can end up building applications by combining several applications, which is obviously confusing. When I use the term application in this book, I m referring to a set of code, objects, or components that s considered to be part of a single, logical unit. Even if parts of the application are in different .NET assemblies or installed on different machines, all the code will be viewed as being part of a singular application.

Figure 13-8. ASP.NET MVC validation Note that MVC will not allow you to save a film with a blank title (because of the validation rules created earlier). Enter a new title, click Save, and note that you were redirected back to the All Films page with the updated data. Whew, we covered a lot here:

namespace SoftnetSolutions.RelayService.PublishChannel { [ServiceBehavior(Name = "PublishEventService", Namespace = "http://SoftnetSolutions.RelayService/", InstanceContextMode = InstanceContextMode.Single)] public class PublishEventService : IPublishEventService { private StringBuilder _messageBuffer = new StringBuilder(); public void PostMessage(PostData postData) { _messageBuffer.Append(string.Format("[{0}]:received message - {1}{2}", DateTime.Now.ToString(), postData.Message, Environment.NewLine)); Console.Write(_messageBuffer.ToString()); } } [DataContract] public class PostData

Public Shared Function CanDeleteObject() As Boolean ' TODO: customize to check user role Return ApplicationContext.User.IsInRole("") End Function #End Region #Region " Factory Methods " Public Shared Function NewEditableRootList() As EditableRootList Return New EditableRootList() End Function Public Shared Function GetEditableRootList(ByVal id As Integer) As EditableRootList Return DataPortal.Fetch(Of EditableRootList)(New Criteria(id)) End Function Private Sub New() ' require use of factory methods End Sub #End Region #Region " Data Access " <Serializable()> _ Private Class Criteria Private mId As Integer Public ReadOnly Property Id() As Integer Get Return mId End Get End Property Public Sub New(ByVal id As Integer) mId = id End Sub End Class Private Overloads Sub DataPortal_Fetch(ByVal criteria As Criteria) ' TODO: load values RaiseListChangedEvents = False Using dr As SqlDataReader = Nothing While dr.Read Add(EditableChild.GetEditableChild(dr)) End While End Using RaiseListChangedEvents = True End Sub Protected Overrides Sub DataPortal_Update() RaiseListChangedEvents = False For Each item As EditableChild In DeletedList item.DeleteSelf() Next DeletedList.Clear()

If you have long (or long-running) methods that you don t want to consciously step over in the debugger, using the DebuggerStepThroughAttribute attribute can save significant time. It is used to avoid stepping through code since it prevents the method from being stepped into. Here s an example usage to mark a validation function that is called often. Make sure you use it in a situation like this when you re sure the method isn t the source of any bugs.

The following code is the same as in the previous section, but this time, the methods are labeled virtual and override. This produces a result that is very different from that of the previous example. In this version, calling the method through the base class invokes the method in the derived class. class MyBaseClass { virtual public void Print() { Console.WriteLine("This is the base class."); } } class MyDerivedClass : MyBaseClass { override public void Print() { Console.WriteLine("This is the derived class."); } } class Program { static void Main() { MyDerivedClass derived = new MyDerivedClass(); MyBaseClass mybc = (MyBaseClass)derived; derived.Print(); Cast to base class mybc.Print(); } } This code produces the following output: This is the derived class. This is the derived class. Other important information about the virtual and override modifiers is the following: The overriding and overridden methods must have the same accessibility. In other words, the overridden method cannot be, for example, private, and the overriding method public. You cannot override a method that is static or is non-virtual. Methods, properties, and indexers (which I covered in the preceding chapter), and another member type, called events (which I will cover later in the text), can all be declared virtual and override.