XAF replace current object Onsaving

Hi Anatol !
Thanks your help, and patience again.

1. "Deleting the current object and replacing it with the another one is definitely not a good practice."
   O.K. But, I do a 1st measurement. This is the 1st record.
   When I do the 2nd measurement, I load from datas from 1st measurement, save the 2nd,-at this time I've got 2 records,- and after that I will delete the 1st. (At this time I've got only 1 record, that's what I need.)
   I think in this situation it is not the current object deletion, simply an another object delete. Isn'it ?
   2."For example, note that it is not necessary to use the Measurement DetailView as a form where measurement details are entered. You can use a DetailView of another object. For example, you can use a TrackMeasurement class that contains the Measurement1 and Measurement2 properties, and operate measurements in this class' business logic."
   Yes, but it will the almost same situation, when I used the PUFFER table. (PUFFER table = MEASUREMENT table, it is only temporary storage).
   3." In this case, it will be easy to understand what measurement was the first, and what was the second. If your business model cannot be extended this way, you can use a DetailView of a non-persistent class to enter measurement details."
   I think, my business model is too complicated to implement the first version.
2. The problem is he next with this implement: I do the 1st measurement. O.K. it saved to the database ISFINAL = false.
   Then, when I do the 2nd measurement it saves to the database,- it is O.K.,- but the 1st measurement stays!!! in the database.
   This is NOT good, because I can do many time 2nd measurement.
   When I finish the 2nd measurement I have 2 choice :
   1 .Insert a new one, with ISFINAL =1. At his point I have a 2 records,- only 1 I need !,- and delete the 1st measurement record.
   (The record with flag ISFINAL = 1, contains 2 measurement, so we have to delete the 1st record.)
3. Search the 1st measurement, modify it - ISFINAL = 1 too, and MODIFY record. This mode solve all my problem.
   The only problem with this solution, as you know,- I have to modify record when I click NEW button.
   The situation is same to, when I implement the measurement procedure like yours.
   I did not mention it before, but in measurement, this measurement process only 1 type.
   I have 3 type of measurement, but they are simply insert a new record into measurement table, that's why I opened this ticket.
   Anatol, thanks for the help,
   Zoltan

I thought that it is required to have both records in the database. I see now, in your situation, it is better to modify the first measurement instead of creating a new one. If so, you can modify the business logic from my sample as follows:

C#
this.Measurement = Session.FindObject<Measurement>(new BinaryOperator("LPN", this.LPN));  
if (Measurement == null) {  
    Measurement = new Measurement(Session);  
    Measurement.LPN = this.LPN;  
} else {  
    Measurement.ID = GenerateMeasurementID();  
    Measurement.IsFinal = true;  
}  

Hi Anatol !
Sorry for the previous long description/explanation, but it is very hard to explain my problems and requirements. It is independent from the language, it is very hard to explain on my native language too.
So, your solution, almost that's what I need for. (Modify the existing record, when the measurement is 2nd, save new record, when the measurement is 1st, is perfect for me.)
1.It can be solutionable, when I use the "New" button on the main menu ? ( I think about to modify Dennis solution in Q423413 ticket. Summarize : if I use the "New" button, the XAF doest not insert new record, only update the selected (searched) record in case of 2nd measurement.)
Sorry, I am not lazy to modify my project upon your suggestion, only time pressure. )
I would like to no use the nonpersistent object in BO logic, if it possible.
(I attach my project BO design. Sorry for the hungarian language. MERES = MEASUREMENT, the other tables are parent tables, that contains the main datas, like PARTNER, TRANSPORTER, etc, but I think, it is non-important for this problem, except for if I create a non-persistent object, I have to setup a many FK for this non-persistent object.)
Thanks for the help,
Zoltan

Hi Anatol !
In my previous post, I forget the next thing :
I tried to working with nonpersistent class but I've got a next message :
The association attribute cannot be used for member 'Storage.Module.BusinessObjects.PARCOSRV.TELEPHELY.MEASUREMENTs' because class 'Storage.Module.BusinessObjects.PARCOSRV.MEASUREMENT' is not persistent.
This is a big problem. If you see my BO logic, I need the FK keys, when the user fills the datas of the measurements.
I think, I cannot use nonpersistent object.
Thanks,
Zoltan

Yes, it is possible to change the New action's behavior to execute a custom code. To do this, either create a WinNewObjectViewController's descendant and override its New action, or subscribe to one of the controller's events such as NewObjectViewController.ObjectCreating and NewObjectViewController.NewObjectAction.Execute.
I do not quite understand why you believe that it is required to link non-persistent classes with persistent classes to implement my suggestion. If you open my sample project, you will see that the non-persistent class is used only to display a form allowing you to enter the LPN value. Unless I am mistaken, you initially tried to implement the following solution: create a Measurement object, enter LPN and replace the created Measurement object with the existing one found by LPN. As we mentioned, this behavior is not supported, so I suggested the following solution: show a DetailView of a non-persistent object, enter LPN in it and display the Measurement object found by LPN in this DetailView. As you can see, this solution only removes the necessity to create a new Measurement object when it is unclear whether or not this object should be created. A Non-persistent class in this scenario is nothing more than a search dialog provider, and it is unclear why it may be required to implement associations between it and persistent classes. I hope that my explanations will be helpful.

Hi Anatol !
"Yes, it is possible to change the New action's behavior to execute a custom code. To do this, either create a WinNewObjectViewController's descendant and override its New action, or subscribe to one of the controller's events such as NewObjectViewController.ObjectCreating and NewObjectViewController.NewObjectAction.Execute."
 I will be happy with a short sample.
"I do not quite understand why you believe that it is required to link non-persistent classes with persistent classes to implement my suggestion."
If you review my previous post, that is includes the screens.7z, and the BOs,- after the user fills the LPN, the user must fill many other datas, that is FK, that's why I think, to use association.
(I read the devexpress documentation, I cannot use association in non-perssiten class.)
"Unless I am mistaken, you initially tried to implement the following solution: create a Measurement object, enter LPN and replace the created Measurement object with the existing one found by LPN."
Yes, you are right, enter LPN- search it,- if does not exist,insert it,- if exist,- update the record.
(P.S. there are 3 types of measurement as as said before, if I remember correctly,- this type is one of them. The other 2, is implemented, but if I can implement your suggestion, I have to rewrite my controller to identify the actual type.)
"As we mentioned, this behavior is not supported, "
If I understand correctly, it not supported default, except for : "WinNewObjectViewController's descendant and override its New action, or subscribe to one of the controller's events such as NewObjectViewController.ObjectCreating and NewObjectViewController.NewObjectAction.Execute." as you write before. Is it O.K. ?
" A Non-persistent class in this scenario is nothing more than a search dialog provider, and it is unclear why it may be required to implement associations between it and persistent classes."
O.K. I understand that.
To summarize this :
I use non-persistent object as a search dialog provider, - if not found, insert a new one, else update the existing one.
I try to implement in my actual project.
Thanks for the help,
Zoltan

Here is an example of how to customize the New action behavior:

C#
public class MeasureController : ViewController {  
    protected override void OnActivated() {  
        base.OnActivated();  
        Frame.GetController<NewObjectViewController>().ObjectCreating += new EventHandler<ObjectCreatingEventArgs>(MeasureController_ObjectCreating);  
    }  

    void MeasureController_ObjectCreating(object sender, ObjectCreatingEventArgs e) {  
        if (e.ObjectType == typeof(Measurement)) {  
            if (View is DetailView && View.ObjectTypeInfo.Type == typeof(MeasurementParameters)) {  
                e.Cancel = true;  
                ObjectSpace.CommitChanges();  
                ((MeasurementParameters)View.CurrentObject).ProcessLPN();  
            } else {  
                e.NewObject = e.ObjectSpace.CreateObject<MeasurementParameters>();  
            }  
        }  
    }  
    protected override void OnDeactivated() {  
        base.OnDeactivated();  
        Frame.GetController<NewObjectViewController>().ObjectCreating -= new EventHandler<ObjectCreatingEventArgs>(MeasureController_ObjectCreating);  
    }  
}  

Replace the MeasureController from my previous example with this controller to see how it works.
Please let me know if you need further assistance.

Hi Anatol !
I cannot answer last week, because I was ill.
So, I started test your suggestion.
Summarize things : I view the http://www.devexpress.com/Support/Center/Question/Details/Q423413 ticket, where the Dennis disable the INSERT new record at new action - to modify this code to not insert,-Dennis implemented this,- only modify the existing record ,- it is notsupported in XAF. Is it right ??
If it is coorectly, the only way the realize my task, only your way, that you suggested to me. Is this correct ?
P.S.
If I use your suggetion, after I inserted a new record into measurement table, the view not updated.
How can I update the view in this situation ?
Thanks for the help,
Zoltan

Yes, XAF does not support passing an unsaved object to the existing DetailView. It is required to create a new DetailView to accomplish this task. This View can be displayed in the current window via the Frame.SetView method.
>> If I use your suggetion, after I inserted a new record into measurement table, the view not updated.
>> How can I update the view in this situation ?
To accomplish this task, you can subscribe to the Committing event of the created view's ObjectSpace (you can obtain it via the ObjectCreatingEventArgs.ObjectSpace property) and refresh the current ListView when this event is raised.

Hi Anatol !
I implemented your suggestion.
I've got a next problem :
The MeasurementParameter class is non-persistent. It is O.K.
If I review my Businessobject design,- Measurement = MERES class. This class contains a lot of FKs. If I fill the LPN in MeasurementParameter class, O.K., but I choose a field that conatains an FK, after I select, the selected value not inserted into the actual field in detailview.
Where did I make a mistake ?
Of course, your solution did not contain FKs.
Maybe is this the problem ?
Thanks for the help,
Zoltan

I am afraid that the problem is not quite clear to me. Please provide a sample project demonstrating it.

Hi Anatol !
I think, I did it something wrong, that's why the previous post borned. I almost finished, and it seems, to fit my needs.
Another problem :
"To accomplish this task, you can subscribe to the Committing event of the created view's ObjectSpace (you can obtain it via the ObjectCreatingEventArgs.ObjectSpace property) and refresh the current ListView when this event is raised."
O.K. I make a viewcontroller, but how do I have to refresh the listview ?
((DevExpress.ExpressApp.ListView)View).Refresh(); was not enogh.
((DevExpress.ExpressApp.ListView)View).CollectionSource.Reload(); ?? (It works.)
or : ListView.ObjectSpace.Refresh ??
Thanks fro the help,
Zoltan

I believe that the CollectionSourceBase.Reload method is the most appropriate, because it reloads only the data source collection without recreating the Session and reloading other objects from the Object Space, unlike the IObjectSpace.Refresh method.

Hi Anatol !
If I use your suggestion, I got a toolbar under the MeasurementParameters class detailview.
How can I disable it by default ?
Thanks for the help,
Zoltan

You can find a solution to this task in the following ticket: Disable ToolBar From DetailPropertyEditor.

Hi Anatol !
Thanks for the help, it works.
Ive got another problem in this scenario :
I would like to close simply the detailview, after I filled the LPN.
View.Close() does not work.
How can I do that ?
Thanks for the help,
Zoltan

The Window.Close method should work. To access the Window instance, use the controller's Frame property. If this does not help, please provide a sample project.

Hi Anatol !
    I've got some problems to implemeting the listview refresh
    I tried it :
    using System;
    using System.Linq;
    using System.Text;
    using DevExpress.ExpressApp;
    using DevExpress.Data.Filtering;
    using System.Collections.Generic;
    using DevExpress.Persistent.Base;
    using DevExpress.ExpressApp.Utils;
    using DevExpress.ExpressApp.Layout;
    using DevExpress.ExpressApp.Actions;
    using DevExpress.ExpressApp.Editors;
    using DevExpress.ExpressApp.Templates;
    using DevExpress.Persistent.Validation;
    namespace MazsaXAF.Module.Win.Controllers
    {
        // For more information on Controllers and their life cycle, check out the http://documentation.devexpress.com/#Xaf/CustomDocument2621 and http://documentation.devexpress.com/#Xaf/CustomDocument3118 help articles.
        public partial class sss : ViewController
        {
            // Use this to do something when a Controller is instantiated (do not execute heavy operations here!).
            public sss()
            {
                InitializeComponent();
                RegisterActions(components);
                // For instance, you can specify activation conditions of a Controller or create its Actions (http://documentation.devexpress.com/#Xaf/CustomDocument2622).
                //TargetObjectType = typeof(DomainObject1);
                //TargetViewType = ViewType.DetailView;
                //TargetViewId = "DomainObject1_DetailView";
                //TargetViewNesting = Nesting.Root;
                //SimpleAction myAction = new SimpleAction(this, "MyActionId", DevExpress.Persistent.Base.PredefinedCategory.RecordEdit);
            }
            // Override to do something before Controllers are activated within the current Frame (their View property is not yet assigned).
            protected override void OnFrameAssigned()
            {
                base.OnFrameAssigned();
                //For instance, you can access another Controller via the Frame.GetController<AnotherControllerType>() method to customize it or subscribe to its events.
            }
            // Override to do something when a Controller is activated and its View is assigned.
            protected override void OnActivated()
            {
                base.OnActivated();
                //For instance, you can customize the current View and its editors (http://documentation.devexpress.com/#Xaf/CustomDocument2729) or manage the Controller's Actions visibility and availability (http://documentation.devexpress.com/#Xaf/CustomDocument2728).
                View.ObjectSpace.Committed += ObjectSpace_Committed;
            }
------------------------------------------------------
    Here is the refresh the listview :
            void ObjectSpace_Committed(object sender, EventArgs e)
            {
                ((DevExpress.ExpressApp.ListView)View).CollectionSource.Reload();

}
--------------------------------------------------------
            // Override to access the controls of a View for which the current Controller is intended.
            protected override void OnViewControlsCreated()
            {
                base.OnViewControlsCreated();
                // For instance, refer to the http://documentation.devexpress.com/Xaf/CustomDocument3165.aspx help article to see how to access grid control properties.
            }
            // Override to do something when a Controller is deactivated.
            protected override void OnDeactivated()
            {
                // For instance, you can unsubscribe from previously subscribed events and release other references and resources.
                base.OnDeactivated();
            }
        }
    }
    How can I refresh the listview,- I think it is only semantical problem,- because in ObjectSpace_ObjectCommitted method the current view is DetailView. How can I reach the listview from this method ?
    Thanks for the help,
    Zoltan

It is required to place the code that handles the IObjectSpace.Committed event and refreshes the ListView to the ListView's controller where the DetailView is created or customized. For example:

C#
void MeasureController_ObjectCreating(object sender, ObjectCreatingEventArgs e) {  
    ...  
    e.ObjectSpace.Committed += ObjectSpace_Committed;  
    ...  
}  
void ObjectSpace_Committed(object sender, EventArgs e) {  
    ((DevExpress.ExpressApp.ListView)View).CollectionSource.Reload();  
}  

Hi Anatol !
Did you think something like this ?
using System;
using System.Linq;
using System.Text;
using DevExpress.ExpressApp;
using DevExpress.Data.Filtering;
using System.Collections.Generic;
using DevExpress.Persistent.Base;
using DevExpress.ExpressApp.Utils;
using DevExpress.ExpressApp.Layout;
using DevExpress.ExpressApp.Actions;
using DevExpress.ExpressApp.Editors;
using DevExpress.ExpressApp.Templates;
using DevExpress.Persistent.Validation;
using DevExpress.Persistent.BaseImpl;
using DevExpress.ExpressApp.SystemModule;
namespace MazsaXAF.Module.Win.Controllers
{
    // For more information on Controllers and their life cycle, check out the http://documentation.devexpress.com/#Xaf/CustomDocument2621 and http://documentation.devexpress.com/#Xaf/CustomDocument3118 help articles.
    public partial class ViewController_FreshListView : ViewController
    {
        // Use this to do something when a Controller is instantiated (do not execute heavy operations here!).
        public ViewController_FreshListView()
        {
            InitializeComponent();
            RegisterActions(components);
            // For instance, you can specify activation conditions of a Controller or create its Actions (http://documentation.devexpress.com/#Xaf/CustomDocument2622).
            //TargetObjectType = typeof(DomainObject1);
            //TargetViewType = ViewType.DetailView;
            //TargetViewId = "DomainObject1_DetailView";
            //TargetViewNesting = Nesting.Root;
            //SimpleAction myAction = new SimpleAction(this, "MyActionId", DevExpress.Persistent.Base.PredefinedCategory.RecordEdit);
        }
        // Override to do something before Controllers are activated within the current Frame (their View property is not yet assigned).
        protected override void OnFrameAssigned()
        {
            base.OnFrameAssigned();
            //For instance, you can access another Controller via the Frame.GetController<AnotherControllerType>() method to customize it or subscribe to its events.
        }
        // Override to do something when a Controller is activated and its View is assigned.
        protected override void OnActivated()
        {
            base.OnActivated();
            //For instance, you can customize the current View and its editors (http://documentation.devexpress.com/#Xaf/CustomDocument2729) or manage the Controller's Actions visibility and availability (http://documentation.devexpress.com/#Xaf/CustomDocument2728).
        }
        // Override to access the controls of a View for which the current Controller is intended.
        protected override void OnViewControlsCreated()
        {
            base.OnViewControlsCreated();
            // For instance, refer to the http://documentation.devexpress.com/Xaf/CustomDocument3165.aspx help article to see how to access grid control properties.
        }
        // Override to do something when a Controller is deactivated.
        protected override void OnDeactivated()
        {
            // For instance, you can unsubscribe from previously subscribed events and release other references and resources.
            base.OnDeactivated();
        }
---------------------------------------------------------------------------------------------------------------------
        private void ViewController_FreshListView_FrameAssigned(object sender, EventArgs e)
        {
            NewObjectViewController standardController = Frame.GetController<NewObjectViewController>();
            standardController.ObjectCreated += new EventHandler<ObjectCreatedEventArgs>(NewObjectCreated);
        }
        void NewObjectCreated(object sender, ObjectCreatedEventArgs e)
        {
            e.ObjectSpace.Committed += ObjectSpace_Committed;
        }
        void ObjectSpace_Committed(object sender, EventArgs e)
        {
            ((DevExpress.ExpressApp.ListView)View).CollectionSource.Reload();
        }
    }
---------------------------------------------------------------------------------------------------------------------
}
O.K. but in this case how can I deactivate the events, or in this case I must not deactivate it ?
Thanks for the help,
Zoltan

Did you mean "unsubscribe"? If so, you can use the Closed event of the DetailView created via the New action. To access this view, use the NewObjectAction.Executed event.

Hi Anatol !
To summarize this :
- To implement your auggestion, I has used the ViewController FrameAssigned event. Is this O.K., or is there any better solution ?
- I mean deactivate to use OnDeactivated() method.
(OnActivated --> Deactivated() is O.K., but I has use OnFrameAssigned. What is to be done in this situation ?)
I think, it would be the easiest way to understand your suggestion, to get a sample code(controller).
Thanks for the help,
Zoltan

It is unclear why you decided to use the FrameAssigned event. The OnActivated method is also appropriate for subscribing to controllers' events. Moreover, this approach is preferable, because the FrameAssigned event is called for all views, while the Activated one - only for views to which the controller is targeted.

Hi Anatol !
O.K. this time I've got a solution.
I didn't know to I have to use NewObjectViewController, so my code :
    public partial class ViewController_FreshListView : ViewController
    {
        // Use this to do something when a Controller is instantiated (do not execute heavy operations here!).
        public ViewController_FreshListView()
        {
            InitializeComponent();
            RegisterActions(components);
            // For instance, you can specify activation conditions of a Controller or create its Actions (http://documentation.devexpress.com/#Xaf/CustomDocument2622).
            //TargetObjectType = typeof(DomainObject1);
            //TargetViewType = ViewType.DetailView;
            //TargetViewId = "DomainObject1_DetailView";
            //TargetViewNesting = Nesting.Root;
            //SimpleAction myAction = new SimpleAction(this, "MyActionId", DevExpress.Persistent.Base.PredefinedCategory.RecordEdit);
        }
        protected override void OnFrameAssigned()
        {
            base.OnFrameAssigned();
        }

protected override void OnActivated()
        {
            base.OnActivated();
            NewObjectViewController standardController = Frame.GetController<NewObjectViewController>();
            standardController.ObjectCreated += new EventHandler<ObjectCreatedEventArgs>(Fresh_View);
        }

void Fresh_View(object sender, ObjectCreatedEventArgs e)
        {
            e.ObjectSpace.Committed += ObjectSpace_Committed;
        }
        void ObjectSpace_Committed(object sender, EventArgs e)
        {
            ((DevExpress.ExpressApp.ListView)View).CollectionSource.Reload();
        }

protected override void OnViewControlsCreated()
        {
            base.OnViewControlsCreated();
        }

protected override void OnDeactivated()
        {
            base.OnDeactivated();
            NewObjectViewController standardController = Frame.GetController<NewObjectViewController>();
            standardController.ObjectCreated -= new EventHandler<ObjectCreatedEventArgs>(Fresh_View);
        }
    }
}
Thanks for the help.

You are welcome!

Hi Anatol !
This is a small reminder about your suggested code :
public class MeasureController : ViewController {
    protected override void OnActivated() {
        base.OnActivated();
        Frame.GetController<NewObjectViewController>().ObjectCreating += new EventHandler<ObjectCreatingEventArgs>(MeasureController_ObjectCreating);
    }
    void MeasureController_ObjectCreating(object sender, ObjectCreatingEventArgs e) {
        if (e.ObjectType == typeof(Measurement)) {
            if (View is DetailView && View.ObjectTypeInfo.Type == typeof(MeasurementParameters)) {
                e.Cancel = true;
                ObjectSpace.CommitChanges();
                ((MeasurementParameters)View.CurrentObject).ProcessLPN();
            } else {
                e.NewObject = e.ObjectSpace.CreateObject<MeasurementParameters>();
            }
        }
    }
    protected override void OnDeactivated() {
        base.OnDeactivated();
        Frame.GetController<NewObjectViewController>().ObjectCreating -= new EventHandler<ObjectCreatingEventArgs>(MeasureController_ObjectCreating);
    }
}
I imlemented your suggestions, and it is everything O.K., except one thing.
The using the MeasureParameters as non-persistent class, nothing else, than a dialog, where the users can fill the LPN.
When I create a new object it is O.K., but if I have to modify the record, how can I do it ?
(I mean how can I modify the LPN ? LPN is used in MeasurementParameters class.)
Thanks for the help,
Zoltan

Is it possible to edit this property directly in the Measurement class in this case?

Hi Anatol !
I the DetailViews layout I hided the LPN property, because the MeasureParameters already incude it. O.K. LPN in MeasurementParameters only for dialog provider, but I unhide the LPN in detailview, I can add LPN twice, it is not good, I think.
What is the best solution ?

1. Hide the LPN in controller only, when user insert the new object, unhide when modify ?
2. Hide the LPN always, and modify LPN through the dialog ?
   Thanks for the help,
   Zoltan

You can use different view models for the standard Measure DetailView and for the Measure DetailView displayed in the MeasureParameters DetailView via the DetailPropertyEditor. To do this, open Model Editor, clone the Measure DetailView, remove the LPN property from it, then find the MeasureParameters.Measurement property in the MeasureParameters_DetailView and pass the cloned view model to its View property.

Hi Anatol !
Please attach a screenshot, where do I have to set another view, because in MeasureParameters.Measuremnt property in MeasurementParameters_DetailView view property can be set up under lyout and item node.
Thanks for the help,
Zoltan

I meant setting the View property of the ViewItem node located in the DetailView | Items collection. I have attached a video demonstrating this approach. Please let me know if you need further clarification.

Hi Anatol !

Sorry for this previous question,- it is obvious, where do I have to set the view,- but I thought, my setup procedure is wrong, because your method is not work. I added another view, but the result stayed the same, as you can see in the attached video.