How do I expose MultiValidationBehavior's children in custom control? - xamarin.forms

Question

I'm creating a custom control for an entry that can be validated.
I did this by creating a ContentView that has a Grid as it's child that contains the entry, error label, etc.
I'd like this to be flexible when it comes to validation, so ideally it would be nice to expose the Entry's MultiValidationBehavior's Children property, or set that property as my control's content property.
As it stands now, I haven't figured out a way to add behaviors to my custom control.
Is this possible?
<ContentView x:Class="MPK.UI.Views.Components.FormEntry"
x:Name="FormEntryControl"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:xct="http://xamarin.com/schemas/2020/toolkit"
xmlns:yummy="clr-namespace:Xamarin.Forms.PancakeView;assembly=Xamarin.Forms.PancakeView"
xmlns:converters="clr-namespace:MPK.UI.Converters;assembly=MPK.UI">
<ContentView.Resources>
<ResourceDictionary>
<converters:IsValidToEntryBorderConverter x:Key="IsValidToEntryBorderConverter"/>
<converters:ErrorsToLabelTextConverter x:Key="ErrorsToLabelTextConverter"/>
<xct:InvertedBoolConverter x:Key="InvertedBoolConverter" />
</ResourceDictionary>
</ContentView.Resources>
<Grid>
<yummy:PancakeView CornerRadius="10"
HeightRequest="50"
HorizontalOptions="FillAndExpand"
BackgroundColor="{StaticResource EntryBackgroundColor}"
Padding="16,0,16,0">
<yummy:PancakeView.Behaviors>
<xct:AnimationBehavior AnimateCommand="{Binding Source={x:Reference FormEntryControl}, Path=ShakeCommand}">
<xct:AnimationBehavior.AnimationType>
<xct:ShakeAnimation />
</xct:AnimationBehavior.AnimationType>
</xct:AnimationBehavior>
</yummy:PancakeView.Behaviors>
<yummy:PancakeView.Border>
<yummy:Border
Color="{Binding IsValid, Source={x:Reference MultiValidationBehavior}, Converter={StaticResource IsValidToEntryBorderConverter}}"
Thickness="1" />
</yummy:PancakeView.Border>
<Entry x:Name="Entry"
Text="{Binding Text, Source={x:Reference FormEntryControl}}"
Placeholder="{Binding Placeholder, Source={x:Reference FormEntryControl}}"
ReturnType="{Binding ReturnType, Source={x:Reference FormEntryControl}}"
ReturnCommand="{Binding ReturnCommand, Source={x:Reference FormEntryControl}}"
PlaceholderColor="{StaticResource EntryPlaceholderTextColor}"
BackgroundColor="Transparent"
IsPassword="{Binding IsPassword, Source={x:Reference FormEntryControl}}"
ClearButtonVisibility="{Binding ClearButtonVisibility, Source={x:Reference FormEntryControl}}">
<Entry.Effects>
<xct:RemoveBorderEffect />
</Entry.Effects>
<Entry.Behaviors>
<xct:MultiValidationBehavior x:Name="MultiValidationBehavior"
IsValid="{Binding IsValid, Source={x:Reference FormEntryControl}, Mode=TwoWay}"
Children="{Binding ValidationBehaviors, Source={x:Reference FormEntryControl}}"/>
<!-- Binding children doesn't work here -->
</Entry.Behaviors>
</Entry>
</yummy:PancakeView>
<xct:Expander Margin="8,4,0,0"
AnimationLength="100"
IsExpanded="{Binding IsValid, Source={x:Reference FormEntryControl}, Mode=OneWay, Converter={StaticResource InvertedBoolConverter}}">
<Label Text="{Binding Errors, Source={x:Reference MultiValidationBehavior}, Converter={StaticResource ErrorsToLabelTextConverter}}"
TextColor="{StaticResource ErrorColor}" />
</xct:Expander>
</Grid>
</ContentView>

Answer 1

The solution was much simpler than I expected.
In my control's code behind I needed to add a property that points to the multivalidationbehavior's children property.
public IList<ValidationBehavior> ValidationBehaviors => TheMultiValidationBehavior.Children;
Using my custom control looks something like this:
<components:FormEntry Placeholder="Name">
<components:FormEntry.ValidationBehaviors>
<xct:TextValidationBehavior MinimumLength="1" xct:MultiValidationBehavior.Error="Min: 1"/>
</components:FormEntry.ValidationBehaviors>
</components:FormEntry>