How to build the correct way of n-tier apps without service and remoting?
 

Sorry if my thread is place in incorrect forum.

Hai All ...

Could anybody help me? i'm praticing how to build the n'tier application. I have read some book tell about this, like "Building Client/Server Applications With VB.NET" by Jeff Levinson, beth massi video tutorial "building simple n-tier applications", and other else.

In my practice, i create 3 projects to handle each layer progress. That are DAL (Data Access Layer), BLL(Business Logic Layer) and UIL (User Interface Layer).

My problem is i don't want to use web service like beth massi do, and i don't want to use remote object like Jeff L do. So i decide to create it by my rules. Here above something that i do.

In DAL Section, I put all datasource like Beth Massi do over here. I also create a manager class like massi do to handle datasource over here. Also in this class, i create the UML structure of this datasource.

'SatuanManager.vb

Option Strict On

Option Explicit On



Imports TradingStudio.BLL.Structures

Imports TradingStudio.BLL.Interfaces

Imports System.Configuration

Imports System.Data

Imports System.Data.SqlClient



Public Class SatuanManager



    'Inherits MarshalByRefObject



    Implements ISatuan



    Public Sub Delete_Record(ByVal intUID As Integer) Implements BLL.Interfaces.ISatuan.Delete_Record



    End Sub



    Public Function Loading_Data() As BLL.DataSet_Satuan Implements BLL.Interfaces.ISatuan.Loading_Data

        Dim ta As New DAL.DataSet_SatuanTableAdapters.UnitTableAdapter

        Dim Satuan As New BLL.DataSet_Satuan



        ta.FillByFlag(Satuan.Unit)



        Return Satuan

    End Function



    Public Function Loading_Record(ByVal intUID As Integer) As BLL.Structures.Structure_Satuan Implements BLL.Interfaces.ISatuan.Loading_Record



    End Function



    Public Sub Save_Record(ByVal StrucSatuan As BLL.Structures.Structure_Satuan, ByRef intUID As Integer) Implements BLL.Interfaces.ISatuan.Save_Record



    End Sub



#Region "Private Attributes"

    Private paUnitUID As Integer

    Private paUnitID As String

    Private paUnitName As String

    Private paUnitModerator As String

    Private paUnitFlag As Boolean

    Private paUnitModified As Date

#End Region



    Public ReadOnly Property UnitUID() As Integer

        Get

            Return paUnitUID

        End Get

    End Property



    Public ReadOnly Property UnitFlag() As Boolean

        Get

            Return paUnitFlag

        End Get

    End Property



    Public ReadOnly Property UnitModified() As Date

        Get

            Return paUnitModified

        End Get

    End Property



    Public Property UnitID() As String

        Get

            Return paUnitID

        End Get

        Set(ByVal value As String)

            paUnitID = value

        End Set

    End Property



    Public Property UnitName() As String

        Get

            Return paUnitName

        End Get

        Set(ByVal value As String)

            paUnitName = value

        End Set

    End Property



    Public Property UnitModerator() As String

        Get

            Return paUnitModerator

        End Get

        Set(ByVal value As String)

            paUnitModerator = value

        End Set

    End Property



End Class

In BLL Section, the dataset which i put in DAL Section auto generate over this section. I also create two class again in this section. There are Interfaces class and Structures class.

'Interfaces.vb

Option Strict On

Option Explicit On



Imports TradingStudio.BLL



Namespace Interfaces



    Public Interface ISatuan

        Function Loading_Data() As DataSet_Satuan

        Function Loading_Record(ByVal intUID As Integer) As Structures.Structure_Satuan

        Sub Save_Record(ByVal StrucSatuan As Structures.Structure_Satuan, ByRef intUID As Integer)

        Sub Delete_Record(ByVal intUID As Integer)

    End Interface



End Namespace

'Structures.vb

Option Strict On

Option Explicit On



Namespace Structures



    <Serializable()> Public Structure Structure_Satuan

        'Public Structure Structure_Satuan

        Public UnitUID As Integer

        Public UnitID As String

        Public UnitName As String

        Public Moderator As String 'Sama Dengan Operator

        Public Flag As Boolean

        Public Modified As Date 'bisa juga dengan menggunakan byte()

    End Structure



End Namespace

In BLL Section, I build user form over here. Over this user form i create a datagridview to show the dataset rows.

'UI_Form.vb

Imports TradingStudio.BLL

Imports TradingStudio.DAL



Public Class Satuan_Main



    Private Sub Satuan_Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load



        Dim DataSatuan As New DAL.SatuanManager



        Me.DataGridView1.DataSource = DataSatuan.Loading_Data.Unit



        With Me.DataGridView1

            .Columns("UnitUID").Visible = False

            .Columns("Flag").Visible = False

            .Columns("Modified").Visible = False

            .ReadOnly = True

        End With



    End Sub

End Class

And Here above my complete source :
myN-Tier

am i build a correct way of n-tier applications? where should i place user interface presentation? where should i place that uml object?

thank's

Re: How to build the correct way of n-tier apps without service and remoting?
 

My answer may appear a little far from your question, but here how I look to it.

In every applications we all write these layers are exist, but they were all exist in one place. Suppose you create a form which include one textbox and save button, in the save button there is an insertion to the information written in the textbox after validation.

The good N-Tire is where you can reduce time and coding for your entire solution (not your single application). The "N" is Unknown number of layer that may exist to help build a good architecture design. where you can re-use what you have build in this application in another application even with another programming language.

I divide the project in 3 parts,
- Form Controls (Button, ListBox, etc...)
- Data handling (connecting, handling, data validating)
- Common Functions

In form design I mean subclassing of each form control using usercontrol and if necessary build an .ocx from it where I can use in other programming language. If I need to change the back color of textbox, I don't need to open each form and change the color of the textbox, I simply change it in one place in the usercontrol.

In data handling, I create a class for each database back-end I use, and I use this class whenever I am developing. Here is a sample

Public Class MySQL

    Public Function CreateMySQLConnectionADODB(ByVal Server, ByVal Database, ByVal UserName, ByVal Password) As ADODB.Connection

        Dim cnn As New ADODB.Connection

        cnn.ConnectionString = _

        "DRIVER={MySQL ODBC 3.51 Driver};" & _

        "SERVER=" & Server & ";" & _

        "DATABASE=" & Database & ";" & _

        "UID=" & UserName & ";" & _

        "PWD=" & Password

        CreateMySQLConnectionADODB = cnn

    End Function

    Public Function CreateMySQLConnectionRDO(ByVal Server, ByVal Database, ByVal UserName, ByVal Password) As RDO.rdoConnection

        Dim _cnnRDOMySQL As New RDO.rdoConnection

        Dim _qryRDOMySQL As New RDO.rdoQuery

        _cnnRDOMySQL.Connect = "uid=root;pwd=" & Password & ";server=" & Server & ";driver={MySQL ODBC 3.51 Driver}; database=" & Database & ";dsn=;"

        _cnnRDOMySQL.CursorDriver = RDO.CursorDriverConstants.rdUseOdbc

        _cnnRDOMySQL.EstablishConnection()

        Return _cnnRDOMySQL

    End Function

End Class

Common function is procedure and function that is used in the application which don't belong to data such as

Public Class MyHardware

    Sub GetCDROMInfo(ByVal __CDROM As String)

        Dim alldrives() As DriveInfo = DriveInfo.GetDrives

        Dim _FreeSpace = Format(alldrives(3).TotalFreeSpace / 1024 / 1024 / 1024, "#0.0")

    End Sub

End Class

The way I do this is.
- Convert the form control to .ocx
- Convert the Data class to .dll
- Convert the common function to .dll

I can re-use them from any place, any environment.

Re: How to build the correct way of n-tier apps without service and remoting?
 

thank's for your reply samir. Now i get a little description about n-tier application architecture ...