HierarchyRepeater support for resource binding in DataSource

Author: exyi

src/Framework/Framework/Controls/GridView.cs

@@ -431,7 +431,7 @@ protected override void RenderContents(IHtmlWriter writer, IDotvvmRequestContext
             head?.Render(writer, context);
 
             // render body
-            var foreachBinding = TryGetKnockoutForeachingExpression().NotNull("GridView does not support DataSource={resource: ...} at this moment.");
+            var foreachBinding = TryGetKnockoutForeachExpression().NotNull("GridView does not support DataSource={resource: ...} at this moment.");
             if (RenderOnServer)
             {
                 writer.AddKnockoutDataBind("dotvvm-SSR-foreach", "{data:" + foreachBinding + "}");

src/Framework/Framework/Controls/HierarchyRepeater.cs

@@ -7,7 +7,9 @@
 using DotVVM.Framework.Binding;
 using DotVVM.Framework.Binding.Expressions;
 using DotVVM.Framework.Binding.Properties;
+using DotVVM.Framework.Compilation.ControlTree.Resolved;
 using DotVVM.Framework.Compilation.Javascript;
+using DotVVM.Framework.Compilation.Validation;
 using DotVVM.Framework.Controls;
 using DotVVM.Framework.Hosting;
 using DotVVM.Framework.ResourceManagement;
@@ -39,14 +41,14 @@ public HierarchyRepeater() : base("div")
         [ControlPropertyBindingDataContextChange(nameof(DataSource))]
         [BindingCompilationRequirements(new[] { typeof(DataSourceAccessBinding) }, new[] { typeof(DataSourceLengthBinding) })]
         [MarkupOptions(Required = true)]
-        public IValueBinding<IEnumerable<object>>? ItemChildrenBinding
+        public IStaticValueBinding<IEnumerable<object>>? ItemChildrenBinding
         {
-            get => (IValueBinding<IEnumerable<object>>?)GetValue(ItemChildrenBindingProperty);
+            get => (IStaticValueBinding<IEnumerable<object>>?)GetValue(ItemChildrenBindingProperty);
             set => SetValue(ItemChildrenBindingProperty, value);
         }
 
         public static readonly DotvvmProperty ItemChildrenBindingProperty
-            = DotvvmProperty.Register<IValueBinding<IEnumerable<object>>?, HierarchyRepeater>(t => t.ItemChildrenBinding);
+            = DotvvmProperty.Register<IStaticValueBinding<IEnumerable<object>>?, HierarchyRepeater>(t => t.ItemChildrenBinding);
 
         /// <summary>
         /// Gets or sets the template for each HierarchyRepeater item.
@@ -147,7 +149,7 @@ protected override void RenderEndTag(IHtmlWriter writer, IDotvvmRequestContext c
 
         protected override void RenderContents(IHtmlWriter writer, IDotvvmRequestContext context)
         {
-            if (RenderOnServer)
+            if (clientRootLevel is null)
             {
                 foreach (var child in Children.Except(new[] { emptyDataContainer!, clientItemTemplate! }))
                 {
@@ -156,7 +158,7 @@ protected override void RenderContents(IHtmlWriter writer, IDotvvmRequestContext
             }
             else
             {
-                clientRootLevel!.Render(writer, context);
+                clientRootLevel.Render(writer, context);
             }
         }
 
@@ -166,12 +168,17 @@ private void SetChildren(IDotvvmRequestContext context, bool renderClientTemplat
             emptyDataContainer = null;
             clientItemTemplate = null;
 
-            if (DataSource is not null)
+            if (GetIEnumerableFromDataSource() is {} enumerable)
             {
-                CreateServerLevel(this.Children, context, GetIEnumerableFromDataSource()!);
+                CreateServerLevel(this.Children,
+                    context,
+                    enumerable,
+                    parentPath: ImmutableArray<int>.Empty,
+                    foreachExpression: this.TryGetKnockoutForeachExpression()
+                );
             }
 
-            if (renderClientTemplate)
+            if (renderClientTemplate && GetDataSourceBinding() is IValueBinding)
             {
                 // whenever possible, we use the dotvvm deterministic ids, but if we are in a client-side template,
                 // we'd get a binding... so we just generate a random Guid, not ideal but it will work.
@@ -185,7 +192,7 @@ private void SetChildren(IDotvvmRequestContext context, bool renderClientTemplat
                 Children.Add(clientRootLevel);
                 clientRootLevel.Children.Add(new HierarchyRepeaterLevel {
                     IsRoot = true,
-                    ForeachExpression = this.TryGetKnockoutForeachingExpression(),
+                    ForeachExpression = this.TryGetKnockoutForeachExpression().NotNull(),
                     ItemTemplateId = clientItemTemplateId,
                 });
             }
@@ -200,19 +207,9 @@ private DotvvmControl CreateServerLevel(
             IList<DotvvmControl> c,
             IDotvvmRequestContext context,
             IEnumerable items,
-            ImmutableArray<int> parentPath = default,
-            string? foreachExpression = default)
+            ImmutableArray<int> parentPath,
+            string? foreachExpression)
         {
-            if (parentPath.IsDefault)
-            {
-                parentPath = ImmutableArray<int>.Empty;
-            }
-
-            foreachExpression ??= ((IValueBinding)GetDataSourceBinding()
-                .GetProperty<DataSourceAccessBinding>()
-                .Binding)
-                .GetKnockoutBindingExpression(this);
-
             var dataContextLevelWrapper = new HierarchyRepeaterLevel {
                 ForeachExpression = foreachExpression
             };
@@ -228,7 +225,7 @@ private DotvvmControl CreateServerLevel(
             var index = 0;
             foreach (var item in items)
             {
-                CreateServerItem(levelWrapper.Children, context, item, parentPath, index);
+                CreateServerItem(levelWrapper.Children, context, item, parentPath, index, foreachExpression is null);
                 index++;
             }
             return dataContextLevelWrapper;
@@ -239,11 +236,12 @@ private DotvvmControl CreateServerItem(
             IDotvvmRequestContext context,
             object item,
             ImmutableArray<int> parentPath,
-            int index)
+            int index,
+            bool serverOnly)
         {
             var itemWrapper = ItemWrapperCapability.GetWrapper();
             c.Add(itemWrapper);
-            var dataItem = new DataItemContainer { DataItemIndex = index };
+            var dataItem = new DataItemContainer { DataItemIndex = index, RenderItemBinding = !serverOnly };
             itemWrapper.Children.Add(dataItem);
             dataItem.SetDataContextTypeFromDataSource(GetDataSourceBinding());
             // NB: the placeholder is needed because during data context resolution DataItemContainers are looked up
@@ -263,7 +261,8 @@ private DotvvmControl CreateServerItem(
             var itemChildren = GetItemChildren(item);
             if (itemChildren.Any())
             {
-                var foreachExpression = ((IValueBinding)ItemChildrenBinding!
+                var foreachExpression = serverOnly ? null : ((IValueBinding)ItemChildrenBinding
+                    .NotNull("ItemChildrenBinding property is required")
                     .GetProperty<DataSourceAccessBinding>()
                     .Binding)
                     .GetParametrizedKnockoutExpression(dataItem)
@@ -349,6 +348,36 @@ private IEnumerable<object> GetItemChildren(object item)
             return ItemChildrenBinding!.Evaluate(tempContainer) ?? Enumerable.Empty<object>();
         }
 
+        [ControlUsageValidator]
+        public static IEnumerable<ControlUsageError> ValidateUsage(ResolvedControl control)
+        {
+            if (!control.TryGetProperty(DataSourceProperty, out var dataSource))
+            {
+                yield return new("DataSource is required on HierarchyRepeater");
+                yield break;
+            }
+            if (dataSource is not ResolvedPropertyBinding { Binding: var dataSourceBinding })
+            {
+                yield return new("HierarchyRepeater.DataSource must be a binding");
+                yield break;
+            }
+            if (!control.TryGetProperty(ItemChildrenBindingProperty, out var itemChildren) ||
+                itemChildren is not ResolvedPropertyBinding { Binding: var itemChildrenBinding })
+            {
+                yield break;
+            }
+
+            if (dataSourceBinding.ParserOptions.BindingType != itemChildrenBinding.ParserOptions.BindingType)
+            {
+                yield return new(
+                    "HierarchyRepeater.DataSource and HierarchyRepeater.ItemChildrenBinding must have the same binding type, use `value` or `resource` binding for both properties.",
+                    dataSourceBinding.DothtmlNode,
+                    itemChildrenBinding.DothtmlNode
+                );
+            }
+        }
+
+
         /// <summary>
         /// An internal control for a level of the <see cref="HierarchyRepeater"/> that renders
         /// the appropriate foreach binding.

src/Framework/Framework/Controls/ItemsControl.cs

@@ -81,7 +81,7 @@ protected IValueBinding GetItemBinding()
         protected IStaticValueBinding GetForeachDataBindExpression() =>
             (IStaticValueBinding)GetDataSourceBinding().GetProperty<DataSourceAccessBinding>().Binding;
 
-        protected string? TryGetKnockoutForeachingExpression(bool unwrapped = false) =>
+        protected string? TryGetKnockoutForeachExpression(bool unwrapped = false) =>
             (GetForeachDataBindExpression() as IValueBinding)?.GetKnockoutBindingExpression(this, unwrapped);
 
         protected string GetPathFragmentExpression()
@@ -98,6 +98,10 @@ protected string GetPathFragmentExpression()
             return stringified;
         }
 
+        /// <summary> Returns data context which is expected in the ItemTemplate </summary>
+        protected DataContextStack GetChildDataContext() =>
+            GetDataSourceBinding().GetProperty<CollectionElementDataContextBindingProperty>().DataContext;
+
         [ApplyControlStyle]
         public static void OnCompilation(ResolvedControl control, BindingCompilationService bindingService)
         {
@@ -128,7 +132,7 @@ protected IBinding GetIndexBinding(IDotvvmRequestContext context)
             {
                 // slower path: create the _index binding at runtime
                 var bindingService = context.Services.GetRequiredService<BindingCompilationService>();
-                var dataContext = GetDataSourceBinding().GetProperty<CollectionElementDataContextBindingProperty>().DataContext;
+                var dataContext = GetChildDataContext();
                 return bindingService.Cache.CreateCachedBinding("_index", new object[] { dataContext }, () =>
                     new ValueBindingExpression<int>(bindingService, new object?[] {
                         dataContext,

src/Framework/Framework/Controls/Repeater.cs

@@ -170,7 +170,7 @@ protected override void RenderBeginTag(IHtmlWriter writer, IDotvvmRequestContext
 
         private KnockoutBindingGroup GetServerSideForeachBindingGroup() =>
             new KnockoutBindingGroup {
-                { "data", TryGetKnockoutForeachingExpression().NotNull() }
+                { "data", TryGetKnockoutForeachExpression().NotNull() }
             };
 
         private (string bindingName, KnockoutBindingGroup bindingValue) GetForeachKnockoutBindingGroup(IDotvvmRequestContext context)
@@ -179,7 +179,7 @@ private KnockoutBindingGroup GetServerSideForeachBindingGroup() =>
             var value = new KnockoutBindingGroup();
 
 
-            var javascriptDataSourceExpression = TryGetKnockoutForeachingExpression().NotNull();
+            var javascriptDataSourceExpression = TryGetKnockoutForeachExpression().NotNull();
             value.Add(
                 useTemplate ? "foreach" : "data",
                 javascriptDataSourceExpression);

src/Tests/ControlTests/ResourceDataContextTests.cs

@@ -138,22 +138,53 @@ public async Task DataContextRevert()
             check.CheckString(r.FormattedHtml, fileExtension: "html");
         }
 
+        [TestMethod]
+        public async Task HierarchyRepeater_SimpleTemplate()
+        {
+            var r = await cth.RunPage(typeof(TestViewModel), @"
+
+                    <!-- without wrapper tags -->
+                    <dot:HierarchyRepeater DataSource={resource: Customers.Items}
+                                           ItemChildrenBinding={resource: NextLevelCustomers}
+                                           RenderWrapperTag=false>
+                        <EmptyDataTemplate> This would be here if the Customers.Items were empty </EmptyDataTemplate>
+                        <span data-id={resource: Id}>{{resource: Name}}</span>
+                    </dot:HierarchyRepeater>
+
+                    <!-- with wrapper tags -->
+                    <dot:HierarchyRepeater DataSource={resource: Customers.Items}
+                                           ItemChildrenBinding={resource: NextLevelCustomers}
+                                           LevelWrapperTagName=ul
+                                           ItemWrapperTagName=li>
+                        <span data-id={resource: Id}>{{resource: Name}}</span>
+                    </dot:HierarchyRepeater>
+               "
+            );
+
+            check.CheckString(r.FormattedHtml, fileExtension: "html");
+        }
+
+
         public class TestViewModel: DotvvmViewModelBase
         {
             public string NullableString { get; } = null;
 
 
             [Bind(Direction.None)]
-            public CustomerData ServerOnlyCustomer { get; set; } = new CustomerData(100, "Server o. Customer");
+            public CustomerData ServerOnlyCustomer { get; set; } = new CustomerData(100, "Server o. Customer", new());
 
             public GridViewDataSet<CustomerData> Customers { get; set; } = new GridViewDataSet<CustomerData>() {
                 RowEditOptions = {
                     EditRowId = 1,
                     PrimaryKeyPropertyName = nameof(CustomerData.Id)
                 },
                 Items = {
-                    new CustomerData(1, "One"),
-                    new CustomerData(2, "Two")
+                    new CustomerData(1, "One", new()),
+                    new CustomerData(2, "Two", new() {
+                        new CustomerData(21, "first pyramid customer", new() {
+                            new CustomerData(211, "second pyramid customer", new())
+                        })
+                    })
                 }
             };
 
@@ -167,7 +198,8 @@ public record CustomerData(
                 int Id,
                 [property: Required]
                 string Name,
-                bool Enabled = true
+                // software for running MLM 😂
+                List<CustomerData> NextLevelCustomers
             );
 
             public string CommandData { get; set; }

src/Tests/ControlTests/testoutputs/ResourceDataContextTests.HierarchyRepeater_SimpleTemplate.html

@@ -0,0 +1,33 @@
+<html>
+	<head></head>
+	<body>
+		
+		<!-- without wrapper tags -->
+		<span data-id="1">One</span>
+		<span data-id="2">Two</span>
+		<span data-id="21">first pyramid customer</span>
+		<span data-id="211">second pyramid customer</span>
+		
+		<!-- with wrapper tags -->
+		<div>
+			<ul>
+				<li>
+					<span data-id="1">One</span>
+				</li>
+				<li>
+					<span data-id="2">Two</span>
+					<ul>
+						<li>
+							<span data-id="21">first pyramid customer</span>
+							<ul>
+								<li>
+									<span data-id="211">second pyramid customer</span>
+								</li>
+							</ul>
+						</li>
+					</ul>
+				</li>
+			</ul>
+		</div>
+	</body>
+</html>

src/Tests/Runtime/config-tests/ConfigurationSerializationTests.SerializeDefaultConfig.json

@@ -750,7 +750,7 @@
         "mappingMode": "InnerElement"
       },
       "ItemChildrenBinding": {
-        "type": "DotVVM.Framework.Binding.Expressions.IValueBinding`1[[System.Collections.Generic.IEnumerable`1[[System.Object, CoreLibrary]], CoreLibrary]], DotVVM.Framework",
+        "type": "DotVVM.Framework.Binding.Expressions.IStaticValueBinding`1[[System.Collections.Generic.IEnumerable`1[[System.Object, CoreLibrary]], CoreLibrary]], DotVVM.Framework",
         "dataContextChange": [
           {
             "$type": "DotVVM.Framework.Binding.CollectionElementDataContextChangeAttribute, DotVVM.Framework",