source/csla10/CSLA.BatchQueue/BatchJobRequest.vb

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+''' <summary>
+''' A helper object used to execute a specified class
+''' from a specified DLL on the server.
+''' </summary>
+''' <remarks>
+''' <para>
+''' A worker object can be provided directly by the client
+''' workstation. In that case, the worker object is passed
+''' by value to the server where it is executed. The drawback
+''' to such an approach is that the worker assembly must be
+''' installed on both client and server.
+''' </para><para>
+''' BatchJobRequest is a worker object that specifies the
+''' type and assembly name of a class on the server. When
+''' this job is run, it dynamically creates an instance of
+''' the specified class and executes it on the server. This
+''' means that the actual worker assembly needs to be installed
+''' only on the server, not on the client.
+''' </para>
+''' </remarks>
+<Serializable()> _
+Public Class BatchJobRequest
+
+  Implements IBatchEntry
+
+  Private mAssembly As String = ""
+  Private mType As String = ""
+
+  ''' <summary>
+  ''' Creates a new object, specifying the type and assembly
+  ''' of the actual worker object.
+  ''' </summary>
+  ''' <param name="Type">The class name of the actual worker object.</param>
+  ''' <param name="Assembly">The name of the assembly containing the actual worker class.</param>
+  Public Sub New(ByVal Type As String, ByVal [Assembly] As String)
+    mAssembly = [Assembly]
+    mType = Type
+  End Sub
+
+  ''' <summary>
+  ''' The class name of the worker object.
+  ''' </summary>
+  Public Property Type() As String
+    Get
+      Return mType
+    End Get
+    Set(ByVal Value As String)
+      mType = Value
+    End Set
+  End Property
+
+  ''' <summary>
+  ''' The name of the assembly containing the actual worker class.
+  ''' </summary>
+  Public Property [Assembly]() As String
+    Get
+      Return mAssembly
+    End Get
+    Set(ByVal Value As String)
+      mAssembly = Value
+    End Set
+  End Property
+
+
+  ''' <summary>
+  ''' Executes the batch job on the server.
+  ''' </summary>
+  ''' <remarks>
+  ''' This method runs on the server - it is called
+  ''' by <see cref="T:CSLA.BatchQueue.Server.BatchEntry" />,
+  ''' which is called by 
+  ''' <see cref="T:CSLA.BatchQueue.Server.BatchQueueService" />.
+  ''' </remarks>
+  ''' <param name="State"></param>
+  Public Sub Execute(ByVal State As Object) _
+      Implements IBatchEntry.Execute
+
+    ' create an instance of the specified object
+    Dim job As IBatchEntry
+    job = CType(AppDomain.CurrentDomain.CreateInstanceAndUnwrap(mAssembly, mType), IBatchEntry)
+
+    ' execute the job
+    job.Execute(State)
+
+  End Sub
+
+#Region " System.Object overrides "
+
+  Public Overrides Function ToString() As String
+
+    Return "BatchJobRequest: " & mType & "," & mAssembly
+
+  End Function
+
+#End Region
+
+End Class