Introduction

This web page tells you how to add a model to the presenter. It assumes you have already created your basic project and also your top level model.

Steps to add a model

A class level reference to the model needs to be stored in each presenter. The reason, for clarity, the model is not passed around to each underlying method from the main control function. Instead the control function asks the presenter to provide a copy of its model, and it is expected the presenter then keeps a reference to the copy.

1)      You need to set up a model folder in the Windows application (if you have not already done this). Your Form_Load event will now look like this) – Replace the "D:\Work\TestData" with a suitable folder on your harddisk.

private void Form1_Load(object sender, EventArgs e) {     NWModel.ModelDirectory = @"D:\Work\TestData";     PresenterMyAppName presenter = new PresenterMyAppName();     this.Controls.Add(presenter);     presenter.NWResizeControls(); }

 

2)      Create a model level variable to store the model object for every presenter.

public class PresenterMyAppName : NWBasePresenter { private ModelMyAppName _model = null;   }

 

3)      Create a function to initialise the model for every presenter.

public override INWModel NWCreateModel() {     _model = new ModelMyAppName();     return _model; }

 

4)      Now create a function for every presenter to uniquely identify the model type. Note that the hard coded strings "AppName&PresenterName" will later on be replaced by application constants. You must include the & character. Any additional arguments to represent the context should also be supplied here.

public override string NWQueryString() {     return "AppName&PresenterName"; } e.g. public override string NWQueryString() {     return RouterSSLPortal.APPLICATION_NAME + "&" + PresenterEditLink.PRESENTER_NAME + "&" + _linkID; }

 

5)      You can now access the model in any presenter function you define. Remember to use the NWIsDirty flag if you change the model. For example,

private void cmdOk_NWEventClick(object sender, NWButton.NWClickEventArgs e) { _model.Name = txtName.NWText; _model.NWIsDirty = true; this.NWGoBackPresenter(e.Url); }

 

6)      You can give your presenter constructor any scalar parameters you like (so long as they can be encoded as a string). This can be used to tell the presenter which part of the model to access. For example,

public class PresenterMyAppName : NWBasePresenter { private ModelMyAppName _model = null;     private string _userID = String.Empty;   public PresenterEditUser(string userID) {             _userID = userID;             InitializeComponent(); }       private void cmdOk_NWEventClick(object sender, NWButton.NWClickEventArgs e)     {         ModelUser user = null;         if (_userID == "NEW")         {             user = new ModelUser();             _model.Users.Add(user);         }         else         {             user = ModelUser.Creator.GetObject(_userID);         } } }