Help creating interface.

[Marraco]

...So, I need to fill in the blanks.

The delegate in the common array is the unique connection between the class who manage the files, and any other class, so the unique thing that UnRegister function does, is to delete the delegate from the common array.

[Marraco]

...
I'm not sure what you are trying to do here. From your first description it sounds like you are loading data then passing each chunk of data to one or more objects...

I think that Explaining more would make more noise than help, but this is a bare bones skeleton of my code:

Imports WindowsApplication1.MyModule.FileLoader
Imports WindowsApplication1.MyModule.FileLoader.ValidationResult

Public Class Form1
    '...
End Class
Public Module MyModule


    Public Class FileLoader
        Public Shared ValidatorsList As New PersonalizedList(Of Validator)

        Public Delegate Function Validator(ByRef ThisLine As ReadData) As ValidationResult
        Public Class PersonalizedList(Of Type)
            Inherits SortedList
            Public Function GetValidKeys() As String()
                '...
            End Function
            Public Sub validate()
                '...
            End Sub
            Public Sub Add(ByVal SomeDelegate As Validator)
                '...
            End Sub
            Public Sub Remove(ByVal SomeDelegate As Validator)
                '...
            End Sub
        End Class
        Public MustInherit Class ValidationResult
            Public Structure ReadData
                '...
            End Structure

            Public MustOverride Function ShouldValidate() As Boolean

            Public MustOverride Sub Validate()
        End Class
        Public Interface IValidatorInterface
            Sub Register()
            Sub UnRegister()
        End Interface
        'All This mess is to call this
        Public Sub New(ByVal FileName As File)
            For Each Line In FileName
                For Each Key In ValidatorsList.GetValidKeys(Line)
                    ValidatorsList(Key).Validate()
                Next
            Next Line
        End Sub
    End Class

    Public Class SomeClass
        Implements IValidatorInterface
        Implements IDisposable


        Public Sub Register() Implements FileLoader.IValidatorInterface.Register
            ValidatorsList.Add(AddressOf MyClassValidator)
        End Sub

        Public Sub UnRegister() Implements FileLoader.IValidatorInterface.UnRegister
            ValidatorsList.Remove(AddressOf MyClassValidator)
        End Sub

        Public Function MyClassValidator(ByRef ThisLine As ReadData) As ValidationResult
            ...
        End Function

        Private disposedValue As Boolean = False        ' To detect redundant calls

        ' IDisposable
        Protected Overridable Sub Dispose(ByVal disposing As Boolean)
            If Not Me.disposedValue Then
                If disposing Then
                    ' TODO: free other state (managed objects).
                    UnRegister()
                End If

                ' TODO: free your own state (unmanaged objects).
                ' TODO: set large fields to null.
            End If
            Me.disposedValue = True
        End Sub

#Region " IDisposable Support "
        ' This code added by Visual Basic to correctly implement the disposable pattern.
        Public Sub Dispose() Implements IDisposable.Dispose
            ' Do not change this code.  Put cleanup code in Dispose(ByVal disposing As Boolean) above.
            Dispose(True)
            GC.SuppressFinalize(Me)
        End Sub
#End Region

    End Class

End Module

[Scott.Macmaster]

Ok, I have a better idea of what your trying to do. However, it still seems wierd that you can have multiple objects that can process the same data.

I don't see the point of using delegates. They're generally used in response to handling events. When loading data you should directly call functions to validate the input. delegates would created unneeded overhead.

I think I may of misunderstood what you had said earlier. I thought you wanted to use reflection to find each instance of certains classes. However, I realize now that you probably wanted to use reflection to find every class that can process your data. If you put all your classes in a module then you can use reflection to search for these objects.

Looks like you made a couple posts while I was typing up a code example. However, it still looks like my example will help.

It looks for all objects in a module that has certain methods. In my example, I have a shared method that is used to determine is the class can process the data or not. interfaces can't define shared methods so I had to check to see if the method was a member. If you need instance members you can make that part of a interface and simply check if the class implements the interface. I didn't check the properties or the return type of the shared method. I thought I let that be an exercise for you.

Well, he's my code example,

Module Module2

    Public Class Data

        Public Processors As New List(Of Processor)

        Public Sub LoadDataFile(ByVal filePath As String)

            Dim type As Type = GetType(ProcessingObjects)

            ' Verify all objects in 'Module ProcessingObjects' have what they need
            Dim memberInfo As MemberInfo() = type.GetNestedTypes()
            For i As Integer = 0 To memberInfo.Count - 1
                Dim currentType As Type = type.GetType(memberInfo(i).ToString())
                Dim baseType As Type = currentType.BaseType

                If baseType.Name() <> "Processor" Then
                    Throw New Exception("Error: " + currentType.Name() + "  does not inherit from Processor")
                End If
                Dim method As MemberInfo = currentType.GetMethod("CanProcessLine")
                If method Is Nothing Then
                    Throw New Exception("Error: " + currentType.Name() + " does not have CanProcessLine")
                End If

            Next

            ' Load each line of data file.
            ' For each line for every class that can process that line and add it to the list of processors
            Dim lines As String() = File.ReadAllLines(filePath)
            For i As Integer = 0 To lines.Count - 1

                For j As Integer = 0 To memberInfo.Count - 1
                    Dim currentType As Type = type.GetType(memberInfo(j).ToString())

                    ' Call the shared member "CanProcessLine" to see if the class can
                    Dim args() As String = {lines(i)}
                    Dim useIt As Boolean = CBool(currentType.InvokeMember("CanProcessLine", BindingFlags.DeclaredOnly Or BindingFlags.Public Or BindingFlags.Static Or BindingFlags.InvokeMethod, Nothing, Nothing, args))

                    If useIt Then
                        ' if so, create an instance and add to list
                        Dim processor As Processor = CType(Activator.CreateInstance(currentType, args), Module2.Processor)
                        Processors.Add(processor)
                    End If

                Next

            Next

        End Sub

    End Class

    Public MustInherit Class Processor
        Protected Data As String

        Public Sub New(ByVal info As String)
            Data = info
        End Sub
    End Class

End Module

Module ProcessingObjects

    Public Class DataType1
        Inherits Processor

        Public Sub New(ByVal data As String)
            MyBase.New(data)
        End Sub

        Public Shared Function CanProcessLine(ByVal line As String) As Boolean
            If line.StartsWith("1") Then
                Return True
            End If
            Return False
        End Function
    End Class

    Public Class DataType2
        Inherits Processor

        Public Sub New(ByVal data As String)
            MyBase.New(data)
        End Sub

        Public Shared Function CanProcessLine(ByVal line As String) As Boolean
            If line.StartsWith("2") Then
                Return True
            End If
            Return False
        End Function
    End Class
End Module

[Marraco]

Ok, I have a better idea of what your trying to do. However, it still seems weird that you can have multiple objects that can process the same data.

I don't see the point of using delegates.

Well, in fact, first, I where thinking on send the entire object reference (instead of delegates), but that way, I was forced to expose some private instances, only to expose a single routine. By the way, I could not pass Me as parameter, so I thinked on passing a pointer to the instance function. That lead me to delegates. After it, I read that a new version of VB.NET (2008?) allows a specific "Function" type. Probably it is a better solution. Not investigated.

As I see, a delegate purpose is to encapsulate a pointer to a function.

They're generally used in response to handling events. When loading data you should directly call functions to validate the input. delegates would created unneeded overhead.

Although is more complex than this, for example, a line can contain the path of a file. Then, I have objects whose responsibility is to manage files, so I want those objects to check if the path is valid, and if not, mark them as unknown path. I don't want other classes messing with files. I have only one module managing all files, and it should not allow any other to touch them.

But then, I have some classes which need a given set of files. For example, any file with extension ".RST" should have also a file ".RDC", and both files need to satisfy a given data structure. That is a specific requirement, who need to be coded on the class who needs it. I can't move his code to other place, otherwise, I can loose track on who is related to that piece of code.
Anyway, I cannot let a third class to open files to check them. The third class, then defines a regular expression, for each kind of file, and is the file manager class who open the file, check it with the regular expression, and closes it.

... and that file path, is related to a given point on a map. Then another class, who manages points on maps, need to identify that point, and check than the line makes sense from his own viewpoint. ¿the location exists? ¿The text is misspelled? ¿a new instance of PointsOnTheMap class need to be created, or this data need to be added on an existing instance?

... and there exists already i7 processors whit 8 virtual cores. (Saddly, I still have not one ( )), So, in the future, I want all those tasks to be capable of run in parallel.

isolating each checking and data processing code, on his own class, requires to define the way each class should behave. Do it class need to access files? Not so easy. It need to agree to a standard, who the file manager rules. A way to force them to adhere to the standard, is to define an interface, so when I need to write the code to access that file, I need to implement the interface. It forces me to no forget to code something, otherwise the compilator rant and whine until I fix the bugs.
¿is there a better way? No idea.

I think I may of misunderstood what you had said earlier. I thought you wanted to use reflection to find each instance of certains classes. However, I realize now that you probably wanted to use reflection to find every class that can process your data. If you put all your classes in a module then you can use reflection to search for these objects.

I don't care if is about Reflection. It only need to do the job, and in a reliable way.

For example, this station contains rain data? I should ask his class if it contains rain data, and then what to do. ¿contains temperature data? Is not my business to decide if it contains temperature data, I should call a class managing temperature.
¿What if tomorrow, some stations add a wild guinea pig counting? I want to write a class named GuineaPigClass. I don't want to recode other code out of the new GuineaPigClass. At startup time, my old code automatically would search for a new class implementing the interface, use it to ask the new class if a given place have anything to do with guinea pig, and if true, then run the guinea pig code.

I don't know how many new classes I can write in the future, which a given interface, or how many instances would do different things.
What new data I gonna read from the file in the future? Don't know. How to validate that data? don't know. But if it contains a file path, I don't want to write again code I already have. The file path would be automatically checked.

And If Nobody checked a given line, then some bug is present, Probably some coding work was left in the task list.
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...
Well, he's my code example,

Module Module2...

It anyway need to know what module contains a class implementing the interface.
I tried to seam it whit this another code, who founds any class implementing the interface:
(Note: If somebody finds this web page with Google probably want this code, because I asked Is there a way to find all classes ... which implement a given Interface?)

Dim asm As Reflection.Assembly = Reflection.Assembly.Load("MyAssemblyName")
Dim types As Type() = asm.GetTypes()
Dim Implementators As Object = types.Where(Function(x) x.GetInterface("IMyInterface") IsNot Nothing)

I like this other a bit more (taken from here):

Dim type As Type = GetType(IMyInterface)
Dim Implementators As IEnumerator = AppDomain.CurrentDomain.GetAssemblies().ToList().SelectMany(Function(f) f.GetTypes()).Where(Function(g) type.IsAssignableFrom(g))

It returns the list of classes which implements a given interface, although I have done nothing useful with it, because, although it accept being declared as Object, or Ienumerable, they don't are cast to that types. Also cannot be cast as array of Type.
I cannot even tell what type is contained in "Implementators" variable. GetType returns a mess, or crashes.
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