I am trying to dynamically modify the items in a List (ObservableCollection) of a ViewModel and have those changes get updated in the View via MvvmCross bindings. My eventual goal is that when a user clicks on a list item, I will pop up a dialog asking them to edit that item. When the dialog is dimissed, the viewmodel will get updated (through an ICommand I assume) and that modified value will be now be in the list.
I haven't looked into dialogs yet, so for now I am just trying to toggle a boolean value each time a list item is clicked and have that value changed in the MvxListView. I have the MxvListView in my View bound to an ObservableCollection in my ViewModel and have an MvxCommand that is getting called when an item is selected. All this is working and I can see the value getting changed in the debugger, however, the new values are not being displayed in the MvxListView. So my question is: How do I get modified data in individual items in an ObservableCollection to bind to an MvxListView?
All of the examples I have seen online use ObservableCollection for dynamic binding but they only ever Add or Delete items. I haven't found any examples of modifying the items. If I change the code in my MvxCommand from modifying the data to adding or deleting an item, the list will get updated. So that tells me I'm close I think.
Rather than copy paste the code in here, I created a sample project on github here to look at:
https://github.com/smulrich/breaktimer
I appreciate the help.
You can simply replace
Breaks[index] = b;
with
Breaks[index] = new DailyBreak() { Reason = b.Reason, TimeOfDay = b.TimeOfDay, Enabled = b.Enabled };
or more reasonable, you should realize INotifyPropertyChanged for class DailyBreak
Diffrent among List, ObservationCollection and INotifyPropertyChanged, please refer to enter link description here
Related
I want a button from the command line bar to be visible or invisible depending on whether a record has been selected in the lookup field from the main form or not.
If no record has been selected, then the button should be displayed. Otherwise not.
For this problem, I want to use the Power Fx in PowerApps, but I haven't found a command yet, which shows me the content or something like that of the lookup field. Other field data types like text have worked without problems.
With Javascript, I already managed it without problems, but I would like to do it also in PowerFx if that should work.
Screenshot: https://i.stack.imgur.com/uqDJ6.png
The records come from the Table Company, where the attribute is Companyname.
Commands where I think they might work:
If([Selected Record];true;false);If(IsBlank([Selected Record]);true;false);If(IsBlankOrError([Selected Record]);true;false);If(IsEmpty([Selected Record]);true;false)
I guess there are 2 scenarios:
The Lookup form control element is a Dropdown with a Selected output property. Then your approach would work like If(IsBlankOrError(DataCardValue1.Selected),true,false)
If your form control element is a ComboBox then you could use If(CountRows(DataCardValue1.SelectedItems)>0,true,false) or the above described IsBlankOrError.
I'm working on a SwiftUI app that is to display a number of entries from a Core Data database. Basically just about what the XCode template for such apps implements.
I've made two changes:
I put the code for the list item view into a separate file (BookmarkableItemView)
I added a property bookmarked to the item, which I called BookmarkableItem
The code in my view to show the list of items is now:
List(bookmarkableItems) { item in
BookmarkableItemView(item: item)
}
In BookmarkableItemView, the item property is an #ObservedObject.
Now, my BookmarkableItemView also contains a button that should toggle the bookmarked property on the item that the view represents. All fine and well - this is easy. But now I have to persist the changes...
I can think of the following two solutions:
Pass an action (simple a (BookmarkableItem) -> Void) to the BookmarkableItemView that's then called when button in the view is pressed
Have the view itself save the managed object context
The latter is a no-go in my opinion. The first solution works. There's now an bookmarkAction property in the BookmarkableItemView, so the above code looks like that:
List(bookmarkableItems) { item in
BookmarkableItemView(bookmarkAction: { toggleBookmark(item) }, item: item)
}
The action is called by the BookmarkableItemView and as a consequence, the toggleBookmark(_ item:) method is called.
But somehow I feel that I'm missing something about bindings in SwiftUI that would make the process easier? How can I have my parent view get a notification when a sub view performs changes to the data model so I can persist them?
onDisappear check if item.hasChanges
or use onChange on item.hasChanges
Is there a way to populate a List property on an object being tested under the "new style" test scenario?
I see some "legacy" test cases which seem to achieve this so am wondering if the new style test scenario handles this.
I added the List model to my test case, which enabled me to expand the sub-property on the object, however there is only one field available there, "empty" (boolean). Is there a way to add an object here? If it makes any difference, the model is an external java dependency.
Update
The reason I wasn't able to add the List of objects was because I didn't explicitly import that object dependency into the test. Once you import it you can follow the steps given in the answer below.
It's definitely possible to manage a List property under the Test Scenario Editor.
Please consider the following example: A Book class with a List<String> property named topics.
Creating a new Test Scenario assets, please select the column where you need to add the List property, and in the right part of the editor select the property expanding the Book class, as shown below:
Pressing Insert Data Ojbect button will assign the selected List property to the selected column:
To fill the data in the List property, please double click on the Insert value cell, in the first scenario data row. A popup will appear. Its aim is to fill data inside a collection
To add a value, please press the Add list value link in the bottom part of the popup. Here, you'll be able to fill a single item on the list
Repeat this step for all the items you need to add to the list. When completed, simply press to Save button
The popup will close and you should see the previously selected data cell filled with a label similar to List(2), the number represents the number of the items in the list.
I am displaying a carousel as discussed in Why is the carousel not showing in the console simulator?. I am now noticing that the end-user can only select once an item from the carousel. When the end-user select another item subsequently, the default fallback intent is triggered.
Is it possible to select multiple items from a carousel?
In my case, the backend service shows the carousel with an output context (named my-carousel) set. The corresponding intent for the actions_intent_OPTION event requires that same context my-carousel as input context (which works as expected for the first selection). When setting the output context my-carousel, I tried several lifespan count values, but without any success.
I don't think there is a way to currently do that the way you tried.
However, you can have another intent trained for keys of carousel (Or use fallback intent) and then process the information this way instead of using actions_intent_OPTION.
But this solution would work only for static data/data matching your database.
I have a DataGridCheckBoxColumn in my DataGrid which is to indicate the rows the user has selected. I want the checkboxes to be checked/unchecked with a single click. Making the column editable (i.e. IsReadOnly="False") means the user has to click twice (first click just selects the row, 2nd click changes the checkbox), so I decided to set/clear the property the column is bound to in the view model code in response to the SelectionChanged trigger firing.
Setting/clearing the property works fine, however as soon as I call NotifyPropertyChanged("name of collection the grid is bound to") to get the view to show the change, this causes the SelectionChanged trigger to fire again. This loops about 10 times until an exception is thrown.
If I remove the call to NotifyPropertyChanged, the SelectionChanged trigger fires once, but of course I don't see any change in the UI. The collection is a PagedCollectionView if this makes any difference.
How can I get this to work? Note - I am using MVVM pattern, so everything is done with bindings to View Model (no code behind).
Thanks
Sounds like you have a infinite loop by design.
but try using the selectionchanging instead of selectionchanged,
or put a isloading flag in your viewmodel and dont call the inotify if the isloading is true
I found a very simple solution that doesn't involve triggers or code behind. See: Silverlight single-click checkbox DataGrid columns
It seems to work by using a column template, but only providing the CellEditingTemplate and no CellTemplate.