question about tutorial 210. Composing Forms with UserControls

Hi,
i was looking at your tutorial "210. Composing Forms with UserControls" where you are displaying user controls on tabpages "on demand". Your solution is much cleaner than a 5000 LoC designer generated file but yet easy to understand. :-) (who said C.A.B. ?)
I see that the tapPage inherits from an abstract tab. This will prevent from opening them in the designer, so I guess that all the UI design should be push down to the user controls and that the tabPage is merely a container that could be changed with mdi or alike.
Could you confirm if I understand it right?

And another question about organizing the work flow of the application.
Say that I want be able to see the product ordered through a special sale rep. To achieve this I put a button on the employeeUserControl. When the user push the button she should see the product tab page filled with the products for that employee. How would you implement that without coupling the different part?

[edit:] uses product instead of orders in the story as orders are shown on the UI. the point is who is making the coordination betwenn the UI parts


Edited by Dominique - 23-Nov-2007 at 3:09am

Hi Greg,

Thank you for your reply.
I am a fast learner, I just need som time to understand so I have some more questions. :-) Sorry for the lengthy post.

Could you correct me if I am wrong:
* A tabpage should handle a usecase (kind of a CAB workItem light if I understood that part of CAB)
* A tabPage controls the UserControls that it hosts
* A Usercontrol handles the UI for a "single entity", merely setting up databinding and showing what the tabPage pushs into it and firing events (CurrentChanged,UserWantCHeckIn, ...).

Is that correct that:
* the FrmMain manage situations where a use case interfere with an other one.
* the "use case controller" part of the code in the tabPage could be taken out if I want to have different UIs supporting the same Use case like flipping between mdi and tabs or having a web interface (to a certain extend).

Some further questions about the code in the solution.
1> I see that the UserControl uses a persistenceManager, wouldn't that break with the TabPage having the reponsability? like when the CustomerUserControl go get customers using it?
2> The use of an interface (IentityUserControl here) should open for loosing the coupling between a tabPage and a concrete UserControl but I can't see you are using it. Is their any reasons for that? (I am thinking of using Interface to have different lay out of the "same" control for different clients)

class EmployeeTabPage : TabPageBase {     public override void LoadUserControls() {       // EmployeeUserControl       mEmployeeUserControl = new EmployeeUserControl(); [...]     }     void mEmployeesBS_CurrentChanged(object sender, EventArgs e) {       Employee currentEmployee = (Employee)mEmployeeUserControl.mEmployeesBS.Current; // How to manage this when using the interface?       mOrderUserControl.LoadMainData(new EntityList<Order>(currentEmployee.Orders));   // should it be an abstract EmployeeUCtrlBase instead?     }     public override void LoadData() {       mOrderUserControl.LoadSupportingData();       //still ok through interface       mEmployeeUserControl.LoadSupportingData(); [...]     }     #region Private Fields     PersistenceManager mPersMgr = PersistenceManager.DefaultManager; IEntityUserControl    mEmployeeUserControl;   // EmployeeUserControl mEmployeeUserControl;     [...]

Thank you again for taking time to explain your code.

Dominique