chore(common): clean up async void in favor of async Task

Author: marin-bratanov

_contentTemplates/common/general-info.md

@@ -1,5 +1,5 @@
 #event-callback-can-be-async
->tip The event is an `EventCallback` and its type can be `void`, or it can also be asynchronous and return `async Task`.
+>tip The event is an `EventCallback` and it can be syncronous (return `void`), or it can also be asynchronous and return `async Task`.
 #end
 
 #ensure-nuget-packge-for-upgrade

components/treeview/data-binding/load-on-demand.md

@@ -21,102 +21,103 @@ The **example** below shows how you can handle load on demand in detail. It uses
 >caption Load on Demand in a TreeView with sample handling of the various cases. Review the code comments for details.
 
 ````CSHTML
-@using Telerik.DataSource.Extensions //used for the .AddRange() extension method
+@using Telerik.DataSource.Extensions
+@* used for the .AddRange() extension method *@
 
 <TelerikTreeView Data="@HierarchicalData" OnExpand="@LoadChildren">
-	<TreeViewBindings>
-		<TreeViewBinding TextField="Category" ItemsField="Products" />
-		<TreeViewBinding Level="1" TextField="ProductName" />
-	</TreeViewBindings>
+    <TreeViewBindings>
+        <TreeViewBinding TextField="Category" ItemsField="Products" />
+        <TreeViewBinding Level="1" TextField="ProductName" />
+    </TreeViewBindings>
 </TelerikTreeView>
 
 @code {
-	public List<ProductCategoryItem> HierarchicalData { get; set; }
-
-	public class ProductCategoryItem
-	{
-		public string Category { get; set; }
-		public int CategoryId { get; set; } //will be used to identify the node, not for rendering in this example
-		public List<ProductItem> Products { get; set; }
-		public bool Expanded { get; set; }
-		public bool HasChildren { get; set; }
-	}
-
-	public class ProductItem
-	{
-		public string ProductName { get; set; }
-		// the following fields are to denote you can keep having hierarchy further down. They are not required
-		// they are not really used in this example and you would have a collection of child items too
-		// see the information about multiple data bindings earlier in this article on using them
-		public bool Expanded { get; set; }
-		public bool HasChildren { get; set; }
-	}
-
-	protected override void OnInitialized()
-	{
-		LoadRootHierarchical();
-	}
-
-	private void LoadRootHierarchical()
-	{
-		HierarchicalData = new List<ProductCategoryItem>();
-
-		HierarchicalData.Add(new ProductCategoryItem
-		{
-			Category = "Category 1",
-			HasChildren = true, // allow the user to expand the item and load children on demand
-			CategoryId = 1 // an identifier for use in the service call for child items
-		});
-
-		HierarchicalData.Add(new ProductCategoryItem
-		{
-			Category = "Category 2",
-			HasChildren = true,
-			CategoryId = 2
-		});
-	}
-
-	private async void LoadChildren(TreeViewExpandEventArgs args)
-	{
-	    // check if the item is expanding, we don't need to do anything if it is collapsing
-	    // in this example we will also check the type of the model to know how to identify the node and what data to load. If you use only one model for all levels, you don't have to do this
-		if (args.Expanded && args.Item is ProductCategoryItem)
-		{
-			ProductCategoryItem currCategory = args.Item as ProductCategoryItem;
-			if (currCategory.Products?.Count > 0)
-			{
-				return; // item has been expanded before so it has data, don't load data again
-						// alternatively, load it again but make sure to handle the child items correctly
-						// either overwrite the entire collection, or use some other logic to append/merge
-			}
-			int itemIdentifier = currCategory.CategoryId;
-			// in a similar fashion, you can identify the item that was just expanded through its properties
-			// in this example, we will hardcode some data and logic for brevity
-			// in a real case, you would probably await a remote endpoint/service
-
-			if (itemIdentifier == 2) // simulate no data for a certain node - the second in our example
-			{
-				currCategory.HasChildren = false; // remove the expand icon from the node
-
-				StateHasChanged(); // inform the UI that the data is changed
-
-				return;
-			}
+    public List<ProductCategoryItem> HierarchicalData { get; set; }
+
+    public class ProductCategoryItem
+    {
+        public string Category { get; set; }
+        public int CategoryId { get; set; } //will be used to identify the node, not for rendering in this example
+        public List<ProductItem> Products { get; set; }
+        public bool Expanded { get; set; }
+        public bool HasChildren { get; set; }
+    }
+
+    public class ProductItem
+    {
+        public string ProductName { get; set; }
+        // the following fields are to denote you can keep having hierarchy further down. They are not required
+        // they are not really used in this example and you would have a collection of child items too
+        // see the information about multiple data bindings earlier in this article on using them
+        public bool Expanded { get; set; }
+        public bool HasChildren { get; set; }
+    }
+
+    protected override void OnInitialized()
+    {
+        LoadRootHierarchical();
+    }
+
+    private void LoadRootHierarchical()
+    {
+        HierarchicalData = new List<ProductCategoryItem>();
+
+        HierarchicalData.Add(new ProductCategoryItem
+        {
+            Category = "Category 1",
+            HasChildren = true, // allow the user to expand the item and load children on demand
+            CategoryId = 1 // an identifier for use in the service call for child items
+        });
+
+        HierarchicalData.Add(new ProductCategoryItem
+        {
+            Category = "Category 2",
+            HasChildren = true,
+            CategoryId = 2
+        });
+    }
+
+    private async Task LoadChildren(TreeViewExpandEventArgs args)
+    {
+        // check if the item is expanding, we don't need to do anything if it is collapsing
+        // in this example we will also check the type of the model to know how to identify the node and what data to load. If you use only one model for all levels, you don't have to do this
+        if (args.Expanded && args.Item is ProductCategoryItem)
+        {
+            ProductCategoryItem currCategory = args.Item as ProductCategoryItem;
+            if (currCategory.Products?.Count > 0)
+            {
+                return; // item has been expanded before so it has data, don't load data again
+                        // alternatively, load it again but make sure to handle the child items correctly
+                        // either overwrite the entire collection, or use some other logic to append/merge
+            }
+            int itemIdentifier = currCategory.CategoryId;
+            // in a similar fashion, you can identify the item that was just expanded through its properties
+            // in this example, we will hardcode some data and logic for brevity
+            // in a real case, you would probably await a remote endpoint/service
+
+            if (itemIdentifier == 2) // simulate no data for a certain node - the second in our example
+            {
+                currCategory.HasChildren = false; // remove the expand icon from the node
+
+                StateHasChanged(); // inform the UI that the data is changed
+
+                return;
+            }
 
             // data requested and received for a certain node
-			List<ProductItem> theProducts = new List<ProductItem>() {
-				new ProductItem { ProductName= $"Category {itemIdentifier} - Product 1" },
-				new ProductItem { ProductName= $"Category {itemIdentifier} - Product 2" }
-			};
-
-			// one way to add child elements to a collection
-			currCategory.Products = new List<ProductItem>();
-			currCategory.Products.AddRange<ProductItem>(theProducts);
-			// the AddRange() method comes from the Telerik.DataSource.Extensions
-
-			StateHasChanged(); // inform the UI that the data is changed
-		}
-	}
+            List<ProductItem> theProducts = new List<ProductItem>() {
+                new ProductItem { ProductName= $"Category {itemIdentifier} - Product 1" },
+                new ProductItem { ProductName= $"Category {itemIdentifier} - Product 2" }
+            };
+
+            // one way to add child elements to a collection
+            currCategory.Products = new List<ProductItem>();
+            currCategory.Products.AddRange<ProductItem>(theProducts);
+            // the AddRange() method comes from the Telerik.DataSource.Extensions
+
+            StateHasChanged(); // inform the UI that the data is changed
+        }
+    }
 }
 ````
 

components/treeview/events.md

@@ -31,7 +31,7 @@ The `OnExpand` event fires when the user expands or collapses a node (either wit
 
     //event handler
 
-    async void ExpandCollapseHandler(TreeViewExpandEventArgs args)
+    async Task ExpandCollapseHandler(TreeViewExpandEventArgs args)
     {
         TreeItem node = args.Item as TreeItem; // Use your actual model(s) for the cast
 

knowledge-base/change-theme-runtime.md

@@ -81,7 +81,7 @@ var themeChanger = {
 <TelerikButton OnClick="ChangeTheme">Change from Default to Material Built-in Theme</TelerikButton>
 
 @code {
-    async void ChangeTheme()
+    async Task ChangeTheme()
     {
         // use the new URL you will use - it can be relative and/or point to a custom theme
         string newThemeUrl = "https://unpkg.com/@progress/kendo-theme-material@latest/dist/all.css";

knowledge-base/common-validation-error-in-tooltip.md

@@ -98,13 +98,13 @@ There are several key aspects in implementing this:
 
     TextValidationModel validationModel = new TextValidationModel() { LengthField = "Too long text" };
 
-    async void HideTooltip()
+    async Task HideTooltip()
     {
         await AnimationContainer.HideAsync();
         // you may also want to create your own EditContext and hook to its OnValidationStateChanged event to hide the tooltip
     }
 
-    async void ShowTooltip()
+    async Task ShowTooltip()
     {
         await AnimationContainer.ShowAsync();
     }

knowledge-base/dropdown-cascading.md

@@ -139,7 +139,7 @@ else if(!string.IsNullOrEmpty(orderStatusMessage))
     }
 
     // sample notification of success and reseting of the process, data classes
-    async void SendOrder()
+    async Task SendOrder()
     {
         CurrentOrder = new Order();
         orderStatusMessage = "Thank you for your order!";
@@ -277,7 +277,7 @@ else if (!string.IsNullOrEmpty(orderStatusMessage))
     }
 
     // sample notification of success and reseting of the process, data classes
-    async void SendOrder()
+    async Task SendOrder()
     {
         CurrentOrder = new Order();
         orderStatusMessage = "Thank you for your order!";
@@ -430,7 +430,7 @@ else if (!string.IsNullOrEmpty(orderStatusMessage))
     }
 
     // sample notification of success and resetting of the process, data classes
-    async void SendOrder()
+    async Task SendOrder()
     {
         CurrentOrder = new Order();
         orderStatusMessage = "Thank you for your order!";

knowledge-base/grid-force-refresh.md

@@ -68,7 +68,7 @@ When using manual operations through the [OnRead event](https://docs.telerik.com
     public ObservableCollection<Employee> GridData { get; set; } = new ObservableCollection<Employee>(); //prevent null reference errors by intializing the field
     DataSourceRequest LastRequest { get; set; }//store the last request so we can repeat it when changing the data
 
-    async void ChangeData()
+    async Task ChangeData()
     {
         SourceData = GenerateData(DateTime.Now.Millisecond.ToString());
         await LoadData();//repeat the last request when changing data

knowledge-base/window-access-dom-element-on-show.md

@@ -58,7 +58,7 @@ Comments in the sample below provide more explanations:
 @code{
     bool ShowWindow { get; set; }
 
-    private async void ShowWindowAndCallJs()
+    async Task ShowWindowAndCallJs()
     {
         ShowWindow = true;