Issue when using BindableLayout and Entry/Editor with special characters

[ppereira-serviceonsites]

          @jfversluis ... I am also running into this issue.  

Using net8.0-ios... This is currently halting my port to MAUI from going to production. It is very weird as the only way I can reliably reproduce it is this:
high level app UI>>>: List page with drill down to detail page.

---updated this to simplify after what I found:
To replicate follow this:

1. start at list and drill down to a detail page
2. click on a field to bring up the Keyboard/Picker/any iOS native UI
3. navigate back to list page... and then go into detail page again.

Looking at the call stack below... it seems to occur on a UITextView... drilling in...
YOU ARE NOT GOING TO BELIEVE THIS...
my field is populated from a DB and it has a double dash -- in it...

• what the system does is the first time, there is no issues... is displays the double dash as 2 characters...
• if you click on ANY field to bring up the keyboard... in my case, I consider it dirty and save as I navigate back.
• it then converts that double dash to a special long dash
• next time in, it barfs with the error below as it tries to show the special character.

SOO... after all this... it seems it is definitely a result of having some special characters in a field... in combination with having previously brought up a keyboard/Picker/ any type of iOS native dialog
P.S.> I tested Char(10) and Char(13) and no issues with them... I don't know how many other types of special character combinations exist...
regardless... this needs to be fixed.

Value cannot be null. (Parameter 'fromPosition') 
----------    
at ObjCRuntime.ThrowHelper.ThrowArgumentNullException(String argumentName) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/ObjCRuntime/ThrowHelper.cs:line 28    
at ObjCRuntime.NativeObjectExtensions.GetNonNullHandle(INativeObject self, String argumentName) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/ObjCRuntime/INativeObject.cs:line 42    
at UIKit.UITextView.GetTextRange(UITextPosition fromPosition, UITextPosition toPosition) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/build/dotnet/ios/generated-sources/UIKit/UITextView.g.cs:line 565    
at Microsoft.Maui.Platform.TextInputExtensions.SetTextRange(IUITextInput platformView, Int32 start, Int32 selectedTextLength)    
at Microsoft.Maui.Controls.Platform.TextExtensions.UpdateText(IUITextInput textInput, InputView inputView, Boolean isEditing)    
at Microsoft.Maui.Controls.Platform.TextExtensions.UpdateText(UITextView textView, InputView inputView)    
at Microsoft.Maui.Controls.Editor.MapText(IEditorHandler handler, Editor editor)    
at Microsoft.Maui.PropertyMapperExtensions.<>c__DisplayClass2_0`2[[Microsoft.Maui.Controls.Editor, Microsoft.Maui.Controls, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Handlers.IEditorHandler, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].<ReplaceMapping>b__0(IEditorHandler h, Editor v, Action`2 p)    
at Microsoft.Maui.PropertyMapperExtensions.<>c__DisplayClass1_0`2[[Microsoft.Maui.Controls.Editor, Microsoft.Maui.Controls, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Handlers.IEditorHandler, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].<ModifyMapping>g__newMethod|0(IElementHandler handler, IElement view)    
at Microsoft.Maui.PropertyMapper`2.<>c__DisplayClass5_0[[Microsoft.Maui.IEditor, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Handlers.IEditorHandler, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].<Add>b__0(IElementHandler h, IElement v)    
at Microsoft.Maui.PropertyMapper.UpdatePropertyCore(String key, IElementHandler viewHandler, IElement virtualView)    
at Microsoft.Maui.PropertyMapper.UpdateProperty(IElementHandler viewHandler, IElement virtualView, String property)    
at Microsoft.Maui.Handlers.ElementHandler.UpdateValue(String property)    
at Microsoft.Maui.Controls.Element.OnPropertyChanged(String propertyName)    
at Microsoft.Maui.Controls.BindableObject.SetValueActual(BindableProperty property, BindablePropertyContext context, Object value, Boolean currentlyApplying, SetValueFlags attributes, SetterSpecificity specificity, Boolean silent)    
at Microsoft.Maui.Controls.BindableObject.SetValueCore(BindableProperty property, Object value, SetValueFlags attributes, SetValuePrivateFlags privateAttributes, SetterSpecificity specificity)    
at Microsoft.Maui.Controls.BindingExpression.ApplyCore(Object sourceObject, BindableObject target, BindableProperty property, Boolean fromTarget, SetterSpecificity specificity)    
at Microsoft.Maui.Controls.BindingExpression.Apply(Boolean fromTarget)    
at Microsoft.Maui.Controls.BindingExpression.BindingExpressionPart.<PropertyChanged>b__50_0()    
at Microsoft.Maui.Controls.DispatcherExtensions.DispatchIfRequired(IDispatcher dispatcher, Action action)    
at Microsoft.Maui.Controls.BindingExpression.BindingExpressionPart.PropertyChanged(Object sender, PropertyChangedEventArgs args)    
at Microsoft.Maui.Controls.BindingExpression.WeakPropertyChangedProxy.OnPropertyChanged(Object sender, PropertyChangedEventArgs e)    
at CommunityToolkit.Mvvm.ComponentModel.ObservableObject.OnPropertyChanged(PropertyChangedEventArgs e)    
at CommunityToolkit.Mvvm.ComponentModel.ObservableObject.OnPropertyChanged(String propertyName)    
at CommunityToolkit.Mvvm.ComponentModel.ObservableObject.SetProperty[WODetails](WODetails& field, WODetails newValue, String propertyName)    
at SOSMobile.WorkOrders.WorkOrderDetailViewModel.set_WOInfo(WODetails value) in C:\Source\net8\SOSMobile\Features\WorkOrders\WorkOrderDetailViewModel.cs:line 40    
at SOSMobile.WorkOrders.WorkOrderDetailViewModel.RefreshData() in C:\Source\net8\SOSMobile\Features\WorkOrders\WorkOrderDetailViewModel.cs:line 138 

Originally posted by @ppereira-serviceonsites in #15937 (comment)

[jyotsnar]

I have the same issue in .NET 8 only in iOS, when setting the text on an 'Editor' via a view model binding property. I do have some '\n' and '\r' values in the text for formatting. This is a showstopper for moving to Maui.

Value cannot be null. (Parameter 'fromPosition')
"   at ObjCRuntime.ThrowHelper.ThrowArgumentNullException(String argumentName) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/ObjCRuntime/ThrowHelper.cs:line 28
at ObjCRuntime.NativeObjectExtensions.GetNonNullHandle(INativeObject self, String argumentName) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/ObjCRuntime/INativeObject.cs:line 42
at UIKit.UITextView.GetTextRange(UITextPosition fromPosition, UITextPosition toPosition) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/build/dotnet/ios/generated-sources/UIKit/UITextView.g.cs:line 565
at Microsoft.Maui.Platform.TextInputExtensions.SetTextRange(IUITextInput platformView, Int32 start, Int32 selectedTextLength)
at Microsoft.Maui.Controls.Platform.TextExtensions.UpdateText(IUITextInput textInput, InputView inputView, Boolean isEditing)
at Microsoft.Maui.Controls.Platform.TextExtensions.UpdateText(UITextView textView, InputView inputView)
at Microsoft.Maui.Controls.Editor.MapText(IEditorHandler handler, Editor editor)
at Microsoft.Maui.PropertyMapperExtensions.<>c__DisplayClass2_0`2[[Microsoft.Maui.Controls.Editor, Microsoft.Maui.Controls, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Handlers.IEditorHandler, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].<ReplaceMapping>b__0(IEditorHandler h, Editor v, Action`2 p)
at Microsoft.Maui.PropertyMapperExtensions.<>c__DisplayClass1_0`2[[Microsoft.Maui.Controls.Editor, Microsoft.Maui.Controls, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Handlers.IEditorHandler, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].<ModifyMapping>g__newMethod|0(IElementHandler handler, IElement view)
at Microsoft.Maui.PropertyMapper`2.<>c__DisplayClass5_0[[Microsoft.Maui.IEditor, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Handlers.IEditorHandler, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].<Add>b__0(IElementHandler h, IElement v)
at Microsoft.Maui.PropertyMapper.UpdatePropertyCore(String key, IElementHandler viewHandler, IElement virtualView)
at Microsoft.Maui.PropertyMapper.UpdateProperty(IElementHandler viewHandler, IElement virtualView, String property)
at Microsoft.Maui.Handlers.ElementHandler.UpdateValue(String property)
at Microsoft.Maui.Controls.Element.OnPropertyChanged(String propertyName)
at Microsoft.Maui.Controls.BindableObject.SetValueActual(BindableProperty property, BindablePropertyContext context, Object value, Boolean currentlyApplying, SetValueFlags attributes, SetterSpecificity specificity, Boolean silent)
at Microsoft.Maui.Controls.BindableObject.SetValueCore(BindableProperty property, Object value, SetValueFlags attributes, SetValuePrivateFlags privateAttributes, SetterSpecificity specificity)
at Microsoft.Maui.Controls.BindingExpression.ApplyCore(Object sourceObject, BindableObject target, BindableProperty property, Boolean fromTarget, SetterSpecificity specificity)
at Microsoft.Maui.Controls.BindingExpression.Apply(Boolean fromTarget)
at Microsoft.Maui.Controls.BindingExpression.BindingExpressionPart.<PropertyChanged>b__50_0()
at Microsoft.Maui.Controls.DispatcherExtensions.DispatchIfRequired(IDispatcher dispatcher, Action action)
at Microsoft.Maui.Controls.BindingExpression.BindingExpressionPart.PropertyChanged(Object sender, PropertyChangedEventArgs args)
at Microsoft.Maui.Controls.BindingExpression.WeakPropertyChangedProxy.OnPropertyChanged(Object sender, PropertyChangedEventArgs e)"

[MichaelShapiro]

I can consistently reproduce this issue when I enter double dash "--" into the Editor on iOS, save it to the db, and then return back to the page with an Editor... and boom, crash. Looks to me as double dash is the problem for the iOS to read and interpret.

[jyotsnar]

I was able to fix the issue by replacing '\n' and '\r\n' values with '\r' before setting the text in the editor

[jyotsnar]

I was able to fix the issue by replacing '\n' and '\r\n' values with '\r' before setting the text in the editor

Actually this fixed the crash only on the simulator not the actual phone - not sure what the difference is

[jyotsnar]

Found that it was because of a "--" that did not work on some iOS devices as @MichaelShapiro mentioned

[kubaflo]

@jyotsnar @ppereira-serviceonsites a possible fix here :) #20584