From 9a5b2f464f97633806e1b917774aaa85947c4d88 Mon Sep 17 00:00:00 2001
From: Hanquez Steven <Steven.Hanquez@outlook.com>
Date: Sat, 16 Oct 2021 11:41:40 +0200
Subject: [PATCH 1/3] Added IsNullOrEmptyConverters Samples

---
 .../IsNotNullOrEmptyConverterPage.xaml        | 29 ++++++++++++++---
 .../IsNullOrEmptyConverterPage.xaml           | 29 ++++++++++++++---
 .../IsNullOrEmptyConverterViewModel.cs        | 31 +++++++++++++++++++
 3 files changed, 81 insertions(+), 8 deletions(-)
 create mode 100644 samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs

diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
index 72a7ff7d12..ed43b33779 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
@@ -4,12 +4,33 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
     xmlns:mct="clr-namespace:CommunityToolkit.Maui.Converters;assembly=CommunityToolkit.Maui"
     xmlns:pages="clr-namespace:CommunityToolkit.Maui.Sample.Pages"
+    xmlns:vm="clr-namespace:CommunityToolkit.Maui.Sample.ViewModels.Converters"
     x:Class="CommunityToolkit.Maui.Sample.Pages.Converters.IsNotNullOrEmptyConverterPage">
+    <pages:BasePage.BindingContext>
+        <vm:IsNullOrEmptyConverterViewModel />
+    </pages:BasePage.BindingContext>
+    <pages:BasePage.Resources>
+        <ResourceDictionary>
+            <mct:IsNotNullOrEmptyConverter x:Key="IsNotNullOrEmptyConverter" />
+        </ResourceDictionary>
+    </pages:BasePage.Resources>
     <pages:BasePage.Content>
-        <StackLayout>
-            <Label Text="IsNotNullOrEmptyConverter"
-                VerticalOptions="CenterAndExpand" 
-                HorizontalOptions="CenterAndExpand" />
+        <StackLayout
+            Padding="10,10"
+            HorizontalOptions="Fill"
+            Spacing="10"
+            VerticalOptions="Fill">
+            <Label Text="The IsNullOrEmptyConverter is a converter that allows users to convert an incoming binding to a bool value. This value represents if the incoming binding value is null or empty." TextColor="{StaticResource NormalLabelTextColor}" />
+            <CollectionView VerticalOptions="StartAndExpand" HorizontalOptions="Center" SelectionMode="Single" ItemsSource="{Binding DummyItemSource}" SelectedItem="{Binding SelectedItem}">
+                <CollectionView.ItemTemplate>
+                    <DataTemplate>
+                        <Label Text="{Binding .}" Margin="10" TextColor="Black" />
+                    </DataTemplate>
+                </CollectionView.ItemTemplate>
+            </CollectionView>
+            <Button VerticalOptions="CenterAndExpand" Text="Clear Selection" Command="{Binding ClearSelectionCommand}"/>
+            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="This label should be false if selected item is null" TextColor="{StaticResource NormalLabelTextColor}" />
+            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="{Binding Path=SelectedItem, Converter={StaticResource IsNotNullOrEmptyConverter }}" />
         </StackLayout>
     </pages:BasePage.Content>
 </pages:BasePage>
\ No newline at end of file
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNullOrEmptyConverterPage.xaml b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNullOrEmptyConverterPage.xaml
index d895d0e94a..ee29302c87 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNullOrEmptyConverterPage.xaml
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNullOrEmptyConverterPage.xaml
@@ -4,12 +4,33 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
     xmlns:mct="clr-namespace:CommunityToolkit.Maui.Converters;assembly=CommunityToolkit.Maui"
     xmlns:pages="clr-namespace:CommunityToolkit.Maui.Sample.Pages"
+    xmlns:vm="clr-namespace:CommunityToolkit.Maui.Sample.ViewModels.Converters"
     x:Class="CommunityToolkit.Maui.Sample.Pages.Converters.IsNullOrEmptyConverterPage">
+    <pages:BasePage.BindingContext>
+        <vm:IsNullOrEmptyConverterViewModel />
+    </pages:BasePage.BindingContext>
+    <pages:BasePage.Resources>
+        <ResourceDictionary>
+            <mct:IsNullOrEmptyConverter x:Key="IsNullOrEmptyConverter" />
+        </ResourceDictionary>
+    </pages:BasePage.Resources>
     <pages:BasePage.Content>
-        <StackLayout>
-            <Label Text="IsNullOrEmptyConverter"
-                VerticalOptions="CenterAndExpand" 
-                HorizontalOptions="CenterAndExpand" />
+        <StackLayout
+            Padding="10,10"
+            HorizontalOptions="Fill"
+            Spacing="10"
+            VerticalOptions="Fill">
+            <Label Text="The IsNullOrEmptyConverter is a converter that allows users to convert an incoming binding to a bool value. This value represents if the incoming binding value is null or empty." TextColor="{StaticResource NormalLabelTextColor}" />
+            <CollectionView VerticalOptions="StartAndExpand" HorizontalOptions="Center" SelectionMode="Single" ItemsSource="{Binding DummyItemSource}" SelectedItem="{Binding SelectedItem}">
+                <CollectionView.ItemTemplate>
+                    <DataTemplate>
+                        <Label Text="{Binding .}" Margin="10" TextColor="Black" />
+                    </DataTemplate>
+                </CollectionView.ItemTemplate>
+            </CollectionView>
+            <Button VerticalOptions="CenterAndExpand" Text="Clear Selection" Command="{Binding ClearSelectionCommand}"/>
+            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="This label should be true if selected item is null" TextColor="{StaticResource NormalLabelTextColor}" />
+            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="{Binding Path=SelectedItem, Converter={StaticResource IsNullOrEmptyConverter}}" />
         </StackLayout>
     </pages:BasePage.Content>
 </pages:BasePage>
\ No newline at end of file
diff --git a/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs b/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs
new file mode 100644
index 0000000000..795fa00b4a
--- /dev/null
+++ b/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs
@@ -0,0 +1,31 @@
+using System.Collections.ObjectModel;
+using Microsoft.Maui.Controls;
+using System.Windows.Input;
+
+namespace CommunityToolkit.Maui.Sample.ViewModels.Converters
+{
+    public class IsNullOrEmptyConverterViewModel : BaseViewModel
+	{
+		string? selectedItem;
+
+		public IsNullOrEmptyConverterViewModel() => ClearSelectionCommand = new Command(() => SelectedItem = null);
+
+		public ObservableCollection<string> DummyItemSource { get; } = new ObservableCollection<string>
+		{
+			"Dummy Item 0",
+			"Dummy Item 1",
+			"Dummy Item 2",
+			"Dummy Item 3",
+			"Dummy Item 4",
+			"Dummy Item 5",
+		};
+
+		public ICommand ClearSelectionCommand { get; }
+
+		public string? SelectedItem
+		{
+			get => selectedItem;
+			set => SetProperty(ref selectedItem, value);
+		}
+	}
+}

From c0082ee2fffbb4861bd3cd962ab87968491251f4 Mon Sep 17 00:00:00 2001
From: Brandon Minnick <13558917+brminnick@users.noreply.github.com>
Date: Sat, 16 Oct 2021 14:48:27 -0700
Subject: [PATCH 2/3] Move Button above CollectionView

---
 .../Converters/IsNotNullOrEmptyConverterPage.xaml |  8 ++++----
 .../Converters/IsNullOrEmptyConverterPage.xaml    |  8 ++++----
 .../Converters/IsNullOrEmptyConverterViewModel.cs | 15 ++++++++-------
 3 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
index ed43b33779..ae85dabdbe 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
@@ -18,9 +18,12 @@
         <StackLayout
             Padding="10,10"
             HorizontalOptions="Fill"
-            Spacing="10"
+            Spacing="16"
             VerticalOptions="Fill">
             <Label Text="The IsNullOrEmptyConverter is a converter that allows users to convert an incoming binding to a bool value. This value represents if the incoming binding value is null or empty." TextColor="{StaticResource NormalLabelTextColor}" />
+            <Button VerticalOptions="CenterAndExpand" Text="Clear Selection" Command="{Binding ClearSelectionCommand}"/>
+            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="This label should be false if selected item is null" TextColor="{StaticResource NormalLabelTextColor}" />
+            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="{Binding Path=SelectedItem, Converter={StaticResource IsNotNullOrEmptyConverter }}" />
             <CollectionView VerticalOptions="StartAndExpand" HorizontalOptions="Center" SelectionMode="Single" ItemsSource="{Binding DummyItemSource}" SelectedItem="{Binding SelectedItem}">
                 <CollectionView.ItemTemplate>
                     <DataTemplate>
@@ -28,9 +31,6 @@
                     </DataTemplate>
                 </CollectionView.ItemTemplate>
             </CollectionView>
-            <Button VerticalOptions="CenterAndExpand" Text="Clear Selection" Command="{Binding ClearSelectionCommand}"/>
-            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="This label should be false if selected item is null" TextColor="{StaticResource NormalLabelTextColor}" />
-            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="{Binding Path=SelectedItem, Converter={StaticResource IsNotNullOrEmptyConverter }}" />
         </StackLayout>
     </pages:BasePage.Content>
 </pages:BasePage>
\ No newline at end of file
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNullOrEmptyConverterPage.xaml b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNullOrEmptyConverterPage.xaml
index ee29302c87..a45158f8bd 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNullOrEmptyConverterPage.xaml
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNullOrEmptyConverterPage.xaml
@@ -18,9 +18,12 @@
         <StackLayout
             Padding="10,10"
             HorizontalOptions="Fill"
-            Spacing="10"
+            Spacing="16"
             VerticalOptions="Fill">
             <Label Text="The IsNullOrEmptyConverter is a converter that allows users to convert an incoming binding to a bool value. This value represents if the incoming binding value is null or empty." TextColor="{StaticResource NormalLabelTextColor}" />
+            <Button VerticalOptions="CenterAndExpand" Text="Clear Selection" Command="{Binding ClearSelectionCommand}"/>
+            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="This label should be true if selected item is null" TextColor="{StaticResource NormalLabelTextColor}" />
+            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="{Binding Path=SelectedItem, Converter={StaticResource IsNullOrEmptyConverter}}" />
             <CollectionView VerticalOptions="StartAndExpand" HorizontalOptions="Center" SelectionMode="Single" ItemsSource="{Binding DummyItemSource}" SelectedItem="{Binding SelectedItem}">
                 <CollectionView.ItemTemplate>
                     <DataTemplate>
@@ -28,9 +31,6 @@
                     </DataTemplate>
                 </CollectionView.ItemTemplate>
             </CollectionView>
-            <Button VerticalOptions="CenterAndExpand" Text="Clear Selection" Command="{Binding ClearSelectionCommand}"/>
-            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="This label should be true if selected item is null" TextColor="{StaticResource NormalLabelTextColor}" />
-            <Label VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" Text="{Binding Path=SelectedItem, Converter={StaticResource IsNullOrEmptyConverter}}" />
         </StackLayout>
     </pages:BasePage.Content>
 </pages:BasePage>
\ No newline at end of file
diff --git a/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs b/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs
index 795fa00b4a..2f4b706074 100644
--- a/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs
+++ b/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs
@@ -1,6 +1,7 @@
 using System.Collections.ObjectModel;
 using Microsoft.Maui.Controls;
 using System.Windows.Input;
+using System.Collections.Generic;
 
 namespace CommunityToolkit.Maui.Sample.ViewModels.Converters
 {
@@ -10,14 +11,14 @@ public class IsNullOrEmptyConverterViewModel : BaseViewModel
 
 		public IsNullOrEmptyConverterViewModel() => ClearSelectionCommand = new Command(() => SelectedItem = null);
 
-		public ObservableCollection<string> DummyItemSource { get; } = new ObservableCollection<string>
+		public IReadOnlyList<string> DummyItemSource { get; } = new[]
 		{
-			"Dummy Item 0",
-			"Dummy Item 1",
-			"Dummy Item 2",
-			"Dummy Item 3",
-			"Dummy Item 4",
-			"Dummy Item 5",
+			"Item 0",
+			"Item 1",
+			"Item 2",
+			"Item 3",
+			"Item 4",
+			"Item 5",
 		};
 
 		public ICommand ClearSelectionCommand { get; }

From 3297391dbe563701304e7a7c74adccfa7167c8c0 Mon Sep 17 00:00:00 2001
From: Brandon Minnick <13558917+brminnick@users.noreply.github.com>
Date: Sat, 16 Oct 2021 14:51:32 -0700
Subject: [PATCH 3/3] Add IsNotNullOrEmptyConverterViewModel

---
 .../IsNotNullOrEmptyConverterPage.xaml        |  2 +-
 .../IsNotNullOrEmptyConverterViewModel.cs     |  9 ++++
 .../IsNullOrEmptyConverterViewModel.cs        | 41 +++++++++----------
 3 files changed, 30 insertions(+), 22 deletions(-)
 create mode 100644 samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNotNullOrEmptyConverterViewModel.cs

diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
index ae85dabdbe..f67e90d563 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Converters/IsNotNullOrEmptyConverterPage.xaml
@@ -7,7 +7,7 @@
     xmlns:vm="clr-namespace:CommunityToolkit.Maui.Sample.ViewModels.Converters"
     x:Class="CommunityToolkit.Maui.Sample.Pages.Converters.IsNotNullOrEmptyConverterPage">
     <pages:BasePage.BindingContext>
-        <vm:IsNullOrEmptyConverterViewModel />
+        <vm:IsNotNullOrEmptyConverterViewModel />
     </pages:BasePage.BindingContext>
     <pages:BasePage.Resources>
         <ResourceDictionary>
diff --git a/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNotNullOrEmptyConverterViewModel.cs b/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNotNullOrEmptyConverterViewModel.cs
new file mode 100644
index 0000000000..ce29439f22
--- /dev/null
+++ b/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNotNullOrEmptyConverterViewModel.cs
@@ -0,0 +1,9 @@
+using System;
+namespace CommunityToolkit.Maui.Sample.ViewModels.Converters;
+
+public class IsNotNullOrEmptyConverterViewModel : IsNullOrEmptyConverterViewModel
+{
+    public IsNotNullOrEmptyConverterViewModel()
+    {
+    }
+}
diff --git a/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs b/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs
index 2f4b706074..f3d4369232 100644
--- a/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs
+++ b/samples/CommunityToolkit.Maui.Sample/ViewModels/Converters/IsNullOrEmptyConverterViewModel.cs
@@ -3,30 +3,29 @@
 using System.Windows.Input;
 using System.Collections.Generic;
 
-namespace CommunityToolkit.Maui.Sample.ViewModels.Converters
+namespace CommunityToolkit.Maui.Sample.ViewModels.Converters;
+
+public class IsNullOrEmptyConverterViewModel : BaseViewModel
 {
-    public class IsNullOrEmptyConverterViewModel : BaseViewModel
-	{
-		string? selectedItem;
+    string? selectedItem;
 
-		public IsNullOrEmptyConverterViewModel() => ClearSelectionCommand = new Command(() => SelectedItem = null);
+    public IsNullOrEmptyConverterViewModel() => ClearSelectionCommand = new Command(() => SelectedItem = null);
 
-		public IReadOnlyList<string> DummyItemSource { get; } = new[]
-		{
-			"Item 0",
-			"Item 1",
-			"Item 2",
-			"Item 3",
-			"Item 4",
-			"Item 5",
-		};
+    public IReadOnlyList<string> DummyItemSource { get; } = new[]
+    {
+        "Item 0",
+        "Item 1",
+        "Item 2",
+        "Item 3",
+        "Item 4",
+        "Item 5",
+    };
 
-		public ICommand ClearSelectionCommand { get; }
+    public ICommand ClearSelectionCommand { get; }
 
-		public string? SelectedItem
-		{
-			get => selectedItem;
-			set => SetProperty(ref selectedItem, value);
-		}
-	}
+    public string? SelectedItem
+    {
+        get => selectedItem;
+        set => SetProperty(ref selectedItem, value);
+    }
 }