Does anyone knows if we can prevent the loading of navigation properties when calling Entity.Add. I checked the source code of EF core and it seems that when TraverseGraph is called (when calling Add) in its internal API it is loading all navigation properties. Is there a way to customize this behavior in order not to load a navigation property in Add. We want to set only the Id int field of the foreign key without loading the Instance of the navigation property. Is this possible??
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I am not able to access a property of a navigation object of an entity in EF, hence my unit test is failing again and again.
In the top of my detailcontroller I have a button to show a list of selected items from various options on the detail controller.
I want to initialize and keep the model, the popover and the list objects in the mastercontroller. How can I get a reference to my mastercontroller to reuse these objects?
Sharing data between views is easiest using a model tied to the component. If you make sure that everything that's selected in the master model is contained in that model, you will be able to use the data from the model in the detail view again.
Pulling data directly from another controller would go against the MVC paradigm and is not recommended (although not impossible, using e.g. the sap.ui.getCore().byId() method). I would not go there unless you have a clear view of the consequences.
I have two ListViews (in separate views). These views are bound to separate view-models but the ListViews contain the same entity type. Both views allow the user to select an item and navigate to it's detail/edit view.
What do I need to do to share this detail view between the two list views?
Here is what I have tried:
Assign the selected item to a property in the detail view's view-model
This initially appeared to work but actually breaks Kendo MVVM. Since the item is in the list view's view-model, assigning it to a property in another view-model causes problems.
Refresh data in each view's show event
While this almost works, it has a couple problems. 1) Getting fresh data all the time can be slow. 2) When saving changes in the detail view and navigating back to the list view, the save is async, so there is no guarantee that those changes will have been persisted before the call for ListView data. This also negates one of the benefits of MVVM and observables.
Share the view-model across views
The examples I have seen that have a list and detail view, have both views sharing a view-model with a selectedItem property. This is not possible in my particular case because I have two list views that navigate to the same detail view - not to mention that I prefer to have a separate view-model for each view so that the view-models don't become a huge mess. Am I supposed to have all views share a single view-model?
What am I missing?
Maybe you could extract the observable model to a plain object model with the toJSON() method, and then create a new observable model from it by wrapping it again. This should clear the existing bindings and avoids the conflicts you've found in your first approach.
var model = kendo.observable( otherModel.toJSON() );
I have an iPhone app based on a tabBar and tableViews. I want the user to be able to click on one tab and access options for filtering the data in the initial tableView.
The problem I'm having is that while the user is selecting filter criteria, I want the main table (not visible) to update. The reason this is important is that I want to show how many cells are still in the table as it is being filtered in the navigation bar.
Currently, the method for filtering the main table (-handleFilter) is called in the viewWillAppear method of my rootViewController class. How can I call this method from my "searchOptions" class?
Thanks for the help!
It sounds like you're conflating too much between your model and your controllers (assuming you're following the MVC design pattern). The other controllers besides the main table should be able to query the model themselves to display the count information without asking the main table controller.
I could be misunderstanding something though, a little more information on what data you're using and how it's being filtered in the controllers attached to the other tab bar items would help.
The most straightforward way would be to give the options controller a pointer to the list controller. Then you can call the method directly.
Other options include defining a method/property on some global object (like your app delegate) to access the list controller from elsewhere in the app, and using a more decentralized mechanism like NSNotificationCenter to pass that information around (rather an a method call), or relying on the model itself to notify all of the controllers accessing it when it changes (possibly using Key-Value Observing, or an explicit delegate protocol).
I'm currently using MVVM in a WPF project, all works very well.
I have one Master view and many Detail views that I manage using a currentView property in my MasterViewModel. By using a datatemplate, I bind a view to a viewmodel.
In fact, my master view has a contentcontrol whose content property is binded to my CurrentView property. When I set this currentview property to a viewmodel or another, it calls the corresponding template.
My problem is that using this, my detail views doesn't have explicit datacontext because it is placed by my datatemplate. So in blend, when I open my view to edit its design, I have no datas to bind to my view. If I set a datacontext to my detailview, in blend I can see all datas I can bind but in runtime, the datacontext set by datatemplate is overrided by the datacontext set in my detailview, so I have no datas during runtime.
Does anyone knows how I can create a good MVVM project, with views managed by datatemplates and with datacontext that we can see with Blend ?
Thanks,
I've got a blog post on this issue: http://www.robfe.com/2009/08/design-time-data-in-expression-blend-3/
My post is all about showing data in blend without having to have that data displayed or even created at runtime.
I solved a similar issue in this post:
How can I use Expression Blend to edit a DataTemplate created in Visual Studio?