I have a custom control (FilePicker) that I want to auto-fill with a value. The structure of my app looks something like this
ScreenView
-> FilePickerView
-> FilePickerViewModel
-> ScreenViewModel
-> Loads Default Value
The problem is that the ScreenViewModel starts with some values pre-bound, but because the bindings in the FilePickerView are two-way, when I bind the FilePickerView.SelectedPath to the ScreenViewModel the value in ScreenViewModel is being overridden when the view activates.
Is there a way to either specify the default bind direction in this.Bind(...) or perhaps a way to say that default values should not be propagated?
Depending on your implementation details, in your viewmodels you can use Skip()/SkipUntil()/etc... Rx extensions to defer initial values coming in from your views.
Related
Searched entire Internet but couldn’t find the modern solution for my problem.
I want to use NSObjectController in pair with Core Data through Cocoa Bindings and struggle to set it up properly. Worth noting that I’m using latest version of Xcode and Swift.
What I’ve done:
For testing purposes I’ve done the following:
Created an macOS app with “Use Core Data” option selected (the app is not document based);
Dragged 2 NSTextFields into the Storyboard Dragged NSObjectController to the view controller scene;
Added Employee Entity to Core Data model with 2 attributes “name” and “surname”;
Done everything from the answer in How do I bind my Array Controller to my core data model?
Set NSObjectController to entity mode and typed in “Employee”,
Prepares Content selected, Use Lazy Fetching selected so all three options checked;
Binded the NSObjectController’s Managed Object Context in bindings inspector to the View Controller’s managedObjectContext;
Binded NSTextFields as follows: Value - Object Controller, Controller key - selection, Model Key Path - name (for 1st text field) and surname (for 2nd).
That’s it.
First set of questions: What I did wrong and how to fix it if it’s not completely wrong approach?
I’ve read in some post on stackoverflow that doing it that way allows automatic saving and fetching from Core Data model. That’s why I assumed it should work.
So here is a Second set of questions:
Is it true?
If it is then why text fields are not filled when view is displayed?
If it is not then how to achieve it if possible (trying to write as less code as possible)?
Third question: If I used approach that is completely wrong would someone help me to connect Core Data and NSObjectController using Cocoa bindings and show me the way of doing so with as less code written as possible using the right approach?
Taking into account that there no fresh posts about this topic in the wilds I think the right answer could help a lot of people that are developing a macOS app.
Thanks in advance!
I think your basic approach is correct, although it is important to understand that you need a real object, an instance, in order for it to work.
Creating a NSManagedObject subclass is generally desirable, and is almost always done in a real project, so you can define and use properties. You can do it easily nowadays by selecting the data model in Xcode's Project Navigator and clicking in the menu: Editor > Create NSManagedObject Subclass…. Technically it is not necessary, and in a demo or proof-of-concept, you often muddle through with NSManagedObject.
Assuming you are using the Xcode project template as you described, wherein AppDelegate has a property managedObjectContext, the following function in your AppDelegate class will maintain, creating when necessary, and return, what I call a singular object – an object of a particular entity, in this case Employee, which your app requires there to be one and only one of in the store.
#discardableResult func singularEmployee() -> NSManagedObject? {
var singularEmployee: NSManagedObject? = nil
let fetchRequest: NSFetchRequest<NSManagedObject> = NSFetchRequest(entityName: "Employee")
let objects = try? self.managedObjectContext.fetch(fetchRequest)
singularEmployee = objects?.first
if singularEmployee == nil {
singularEmployee = NSEntityDescription.insertNewObject(forEntityName: "Employee", into: self.managedObjectContext)
}
return singularEmployee
}
Then, add this line of code to applicationDidFinishLaunching
singularEmployee()
I have a sap.m.TabContainer control with multiple sap.m.TabContainerItem controls. Each of the TabContainerItem controls have a number of their own controls on them. I have created a custom control (DBPanel) with a label and text field. It also has an enabled property for which I have overridden the setEnabled(boolean) method to enable/disable the internal text field within DBPanel. There are five (5) of these DBPanel controls on a specific TabContainerItem. When I call setEnabled(true) on each of these DBPanels, only three of the five become enabled. When I switch to another TabContainerItem and then back to this one, the final two DBPanels are also enabled. It is almost as if the TabContainerItem needs to be re-rendered. But I have read elsewhere that if rerender or invalidate need to be specifically called then there is something wrong with the code.
Any help would be appreciated.
Thank you
At your overridden method, you can try to call the original method that is extended. If you don't need extra logic rather than disabling or enabling it, you don't need to extend that method but I guess you have some.
First check whether superclass implements the method and then call the
method with the original arguments
if (DBPanel.prototype.setEnabled)
DBPanel.prototype.setEnabled.apply(this, arguments);
I've created a sandbox with a demonstration of binding UI components to both data and state: http://dojo-sandbox.net/public/51073/1
It's my plan to generate code from a page definition creating a page-level widget which is templated. This widget will have its own scope, where the model and state will reside, which I am trying to simulate in the sandbox by way of the Page object.
The sandbox is working because the Page object is in the global state, which appears to be the default context for object resolution in mvc binding.
However the plan is to have a view widget supporting each page with both the Model and State contained within the widget's scope. The generated template for the view would be bound to both the Model and the State. I can establish the source via the 'target' property, but when the same UI component must be bound to two different models, one for value and one for state, the single source doesn't support this.
The Model data will come to me from the back-end, and the State data is derived via the State.Execute method once the Model data is present.
I've taken a look at the 'rel:' parameter of at(), but don't see how to leverage this syntax within a specific context, ie my view widget's scope. It seems to be working fine for the default global scope.
Is there a standard way to direct the data-dojo-props value binding at one source, and the data-mvc-bindings for attributes at another? Or, more precisely, what is the at('rel:') syntax which will support specifying the context of the relation, and not rely on the 'target' of the widget or containing widget?
If there is no way to specify the 'target' at this level, I will generate more logic in the Execute method to specifically set the html attribute on the component during state compilation.
data-mvc-bindings is for allowing non-widgets use dojox/mvc/at. If a widget is declared for an element data-dojo-props is the one for use instead.
If target is specified via data-dojo-props or data-mvc-bindings, it’ll be set eventually to the widget.target. ”rel:” syntax looks for a widget having .target up in DOM tree.
It means that one “group” cannot have more than one "relative binding target”, in case it’s one of your questions. You can have a “scope object” that contains pointers to more than one models and use it as a “relative binding target”, that may serve a similar purpose:
<div data-dojo-type="dijit/_WidgetBase"
data-dojo-props="target: {model0: model0, model1: model1}">
<input type="text"
data-dojo-type="dijit/form/TextBox"
data-dojo-props="value: at('rel:model0', 'value'),
disabled: at('rel:model1', 'disabled')" />
</div>
A working example can be found at http://jsfiddle.net/asudoh/M3bRC/. Hope these help.
Best, - Akira
I am using DevExpress controls in a winform app I am building for internal use. My app has about 30 forms in total and I am trying to figure out a way to allow my user's to select a theme. I have seen this mentioned here at SO multiple times in answers to other posts.
I understand how the StyleController works, I believe, but what I am wondering is how I can use 1 Style controller for the whole app.
Right now I am trying to create 1 StlyeController at the Shell form and then pass a reference to it to each child form. From there I then have to programatically set the StyleController property for each control. I don't mind I just wonder, especially from those who have done this, if there is a simpler way?
It is very simple. This example is assuming that you are using skins.
In the constructor of your main form calls:
DevExpress.Skins.SkinManager.EnableFormSkins();
This will enable your form to use the current skin. It is also important that each of your forms derived from XtraForm.
After that you need to setup the global look and feel object for your application:
//This set the style to use skin technology
DevExpress.LookAndFeel.UserLookAndFeel.Default.Style = DevExpress.LookAndFeel.LookAndFeelStyle.Skin;
//Here we specify the skin to use by its name
DevExpress.LookAndFeel.UserLookAndFeel.Default.SetSkinStyle("Black");
If you want to set the look and feel of your application like Office 2003, the setup is different. You just have to call the following function:
DevExpress.LookAndFeel.UserLookAndFeel.Default.SetOffice2003Style();
So, every control of devexpress will use these settings to paint themselves. It is possible to specify a custom LookAndFeel object for some controls but I never used it because I dont see the point to have a custom display for a control or a form.
Exception:
There is one exception in Devexpress framework. The NavBarControl does not use the skin technology automatically from your global LookAndFeel object, you need to specify a setting to enable that:
//To use the current skin
youNavBarControl.PaintStyleName = "SkinNavigationPane";
//To use the current look and feel without the skin
youNavBarControl.PaintStyleName = "NavigationPane";
With version 11.2 I used the information in this article:
http://www.devexpress.com/Support/Center/p/K18013.aspx
In summary :
* Inherit all your forms from XtraForm
* Leave look and feel settings default so that they use the default skin
* Modify the default skin with the following line of code:
DevExpress.LookAndFeel.UserLookAndFeel.Default.SkinName = "DevExpress Dark Style";
I have a region named "ActiveModule" and want to re-use it with different views, for example you press the search button and I show the search view in there, etc. etc.
The only way I can ATM do that is to deactivate all the active views in that region and then activate the view I like, this is a bit dirty, is there a "viewManager" or something similar I can use?
If your region is a ContentControl or derives from ContentControl, then there can only be one active view at a time, and you only need to activate the search view on the region.
Did you consider to use a type of contentControl that is able to show multiple views?
For example you can use a TabControl like this:
<TabControl Name="MainRegion" Regions:RegionManager.RegionName="MainRegion"/>
You can now add more than one view to the region. Use INavigationAware and IActiveAware interfaces from Prism to be able to do navigation on the views (activate them, find the correct view etc.).
If you are using a IRegionManager, you can remove all of the views whose types you recognize and then add your own.
foreach (var view in _regionsManager.Regions["MyRegion"].Views.ToArray())
{
if (view is MyType ||
view is MyOtherType)
_regionsManager.Regions["MyRegion"].Remove(view);
}
_regionsManager.AddToRegion("MyRegion", typeof(MyView));
Its by no means ideal, but it works. :)
To my knowledge what you are doing is the only way, theoretically in SCSF the top most view was activated by the framework. You could create ur own ViewManager or a ShowViewService equivalent to get this done. MAtter of fact, thats what i have done!
Not sure how you laid out your framework but if you are using navigation related framework you can simply call
regionManager.RequestNavigate(RegionNames.MainContentRegion, new Uri("your target view" + parameters, UriKind.Relative));
the above line will take care of deactivating other views in the region.
Otherwise if you do view discovery or view injection you can use the approach here
region.Activate(view);