TemplateHost control

src/Framework/Framework/Controls/TemplateHost.cs

@@ -3,7 +3,10 @@
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using DotVVM.Framework.Binding;
+using DotVVM.Framework.Compilation.ControlTree;
 using DotVVM.Framework.Hosting;
+using DotVVM.Framework.Utils;
 
 namespace DotVVM.Framework.Controls
 {
@@ -18,13 +21,38 @@ public class TemplateHost : DotvvmControl
         /// Gets or sets the template that will be rendered inside this control.
         /// </summary>
         [MarkupOptions(AllowBinding = false, MappingMode = MappingMode.Attribute, Required = true)]
-        public ITemplate? ContentTemplate { get; set; }
+        public ITemplate? Template
+        {
+            get { return (ITemplate?)GetValue(TemplateProperty); }
+            set { SetValue(TemplateProperty, value); }
+        }
+        public static readonly DotvvmProperty TemplateProperty
+            = DotvvmProperty.Register<ITemplate, TemplateHost>(c => c.Template, null);
+
 
 
         protected internal override void OnLoad(IDotvvmRequestContext context)
         {
-            ContentTemplate?.BuildContent(context, this);
+            var placeHolder = new PlaceHolder();
+            Template.NotNull("TemplateHost.Template is required").BuildContent(context, placeHolder);
+
+            // validate data context of the passed template
+            var myDataContext = this.GetDataContextType()!;
+            if (!CheckChildrenDataContextStackEquality(myDataContext, placeHolder.Children))
+            {
+                throw new DotvvmControlException(this, "Passing templates into markup controls or to controls which change the binding context, is not supported!");
+            }
+
+            Children.Add(placeHolder);
+
             base.OnLoad(context);
         }
+
+        private bool CheckChildrenDataContextStackEquality(DataContextStack desiredDataContext, DotvvmControlCollection children)
+        {
+            return children.Select(c => c.GetDataContextType())
+                .Where(t => t != null)
+                .All(t => Equals(t, desiredDataContext));
+        }
     }
 }

src/Samples/Common/DotVVM.Samples.Common.csproj

@@ -43,6 +43,9 @@
     <None Remove="Views\ControlSamples\Repeater\IndexInNestedRepeater.dothtml" />
     <None Remove="Views\ControlSamples\Repeater\NamedTemplate.dothtml" />
     <None Remove="Views\ControlSamples\RouteLink\RouteLinkQueryParameters.dothtml" />
+    <None Remove="Views\ControlSamples\TemplateHost\Basic.dothtml" />
+    <None Remove="Views\ControlSamples\TemplateHost\TemplatedListControl.dotcontrol" />
+    <None Remove="Views\ControlSamples\TemplateHost\TemplatedMarkupControl.dotcontrol" />
     <None Remove="Views\ControlSamples\UpdateProgress\UpdateProgressQueues.dothtml" />
     <None Remove="Views\ControlSamples\UpdateProgress\UpdateProgressRedirect.dotmaster" />
     <None Remove="Views\ControlSamples\UpdateProgress\UpdateProgressRedirect1.dothtml" />

src/Samples/Common/DotvvmStartup.cs

@@ -28,6 +28,7 @@
 using DotVVM.Samples.Common.ViewModels.FeatureSamples.JavascriptTranslation;
 using DotVVM.Samples.Common.Views.FeatureSamples.PostbackAbortSignal;
 using DotVVM.Samples.Common.ViewModels.FeatureSamples.BindingVariables;
+using DotVVM.Samples.Common.Views.ControlSamples.TemplateHost;
 
 namespace DotVVM.Samples.BasicSamples
 {
@@ -195,8 +196,10 @@ private static void AddControls(DotvvmConfiguration config)
             config.Markup.AddMarkupControl("cc", "RecursiveTextRepeater2", "Views/FeatureSamples/PostBack/RecursiveTextRepeater2.dotcontrol");
             config.Markup.AddMarkupControl("cc", "ModuleControl", "Views/FeatureSamples/ViewModules/ModuleControl.dotcontrol");
             config.Markup.AddMarkupControl("cc", "Incrementer", "Views/FeatureSamples/ViewModules/Incrementer.dotcontrol");
+            config.Markup.AddMarkupControl("cc", "TemplatedListControl", "Views/ControlSamples/TemplateHost/TemplatedListControl.dotcontrol");
+            config.Markup.AddMarkupControl("cc", "TemplatedMarkupControl", "Views/ControlSamples/TemplateHost/TemplatedMarkupControl.dotcontrol");
+            config.Markup.AddCodeControls("cc", typeof(CompositeControlWithTemplate));
             config.Markup.AddCodeControls("cc", typeof(Loader));
-
             config.Markup.AddMarkupControl("sample", "EmbeddedResourceControls_Button", "embedded://EmbeddedResourceControls/Button.dotcontrol");
 
             config.Markup.AutoDiscoverControls(new DefaultControlRegistrationStrategy(config, "sample", "Views/"));

src/Samples/Common/ViewModels/ControlSamples/TemplateHost/BasicViewModel.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using DotVVM.Framework.ViewModel;
+
+namespace DotVVM.Samples.Common.ViewModels.ControlSamples.TemplateHost
+{
+    public class BasicViewModel : DotvvmViewModelBase
+    {
+
+        public List<IntValue> ObjectList { get; set; } = new List<IntValue>()
+        {
+            new IntValue() { Value = 1 },
+            new IntValue() { Value = 2 },
+            new IntValue() { Value = 3 }
+        };
+
+        public IntValue CreateObject()
+        {
+            return new IntValue() { Value = 1 };
+        }
+    }
+
+    public class IntValue
+    {
+        public int Value { get; set; }
+    }
+}
+

src/Samples/Common/Views/ControlSamples/TemplateHost/Basic.dothtml

@@ -0,0 +1,44 @@
+@viewModel DotVVM.Samples.Common.ViewModels.ControlSamples.TemplateHost.BasicViewModel, DotVVM.Samples.Common
+
+<!DOCTYPE html>
+
+<html lang="en" xmlns="http://www.w3.org/1999/xhtml">
+<head>
+    <meta charset="utf-8" />
+    <title></title>
+</head>
+<body>
+
+    <h1>TemplateHost</h1>
+
+    <cc:CompositeControlWithTemplate HeaderText="Form 1">
+        <ContentTemplate>
+            <p>hello from template</p>
+        </ContentTemplate>
+    </cc:CompositeControlWithTemplate>
+
+    <cc:CompositeListControlWithTemplate DataSource="{value: ObjectList}" OnCreateItem="{command: _root.CreateObject}">
+        <ItemTemplate>
+            <big>{{value: Value}}</big>
+            <dot:Button Text="+" Click="{staticCommand:  Value = Value + 1}" />
+            <dot:Button Text="-" Click="{staticCommand:  Value = Value - 1}" />
+        </ItemTemplate>
+    </cc:CompositeListControlWithTemplate>
+
+    <%--<cc:TemplatedMarkupControl HeaderText="Form 1">
+        <ContentTemplate>
+            <p>hello from template</p>
+        </ContentTemplate>
+    </cc:TemplatedMarkupControl>
+
+    <cc:TemplatedListControl DataSource="{value: ObjectList}" OnCreateItem="{command: _root.CreateObject}">
+        <ItemTemplate>
+            <big>{{value: Value}}</big>
+            <dot:Button Text="+" Click="{staticCommand:  Value = Value + 1}" />
+            <dot:Button Text="-" Click="{staticCommand:  Value = Value - 1}" />
+        </ItemTemplate>
+    </cc:TemplatedListControl>--%>
+</body>
+</html>
+
+

src/Samples/Common/Views/ControlSamples/TemplateHost/CompositeControlWithTemplate.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Text;
+using DotVVM.Framework.Binding;
+using DotVVM.Framework.Controls;
+
+namespace DotVVM.Samples.Common.Views.ControlSamples.TemplateHost
+{
+    public class CompositeControlWithTemplate : CompositeControl 
+    {
+
+        public static DotvvmControl GetContents(
+            ValueOrBinding<string> headerText,
+            ITemplate contentTemplate
+        )
+        {
+            return new HtmlGenericControl("fieldset")
+                .AppendChildren(
+                    new HtmlGenericControl("legend", new TextOrContentCapability() { Text = headerText }),
+                    new Framework.Controls.TemplateHost() { Template = contentTemplate }
+                );
+        }
+
+    }
+}

src/Samples/Common/Views/ControlSamples/TemplateHost/CompositeListControlWithTemplate.cs

@@ -0,0 +1,62 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using DotVVM.Framework.Binding;
+using DotVVM.Framework.Binding.Expressions;
+using DotVVM.Framework.Controls;
+using DotVVM.Framework.Utils;
+
+namespace DotVVM.Samples.Common.Views.ControlSamples.TemplateHost
+{
+    public class CompositeListControlWithTemplate : CompositeControl
+    {
+        private readonly BindingCompilationService bindingCompilationService;
+
+        public CompositeListControlWithTemplate(BindingCompilationService bindingCompilationService)
+        {
+            this.bindingCompilationService = bindingCompilationService;
+        }
+
+        public IEnumerable<DotvvmControl> GetContents(
+            IValueBinding<IEnumerable> dataSource,
+
+            [ControlPropertyBindingDataContextChange("DataSource", order: 0)]
+            [CollectionElementDataContextChange(order: 1)]
+            ITemplate itemTemplate,
+
+            ICommandBinding<object> onCreateItem
+        )
+        {
+            yield return new Framework.Controls.Repeater() {
+                    ItemTemplate = new DelegateTemplate(_ => new HtmlGenericControl("div")
+                        .AppendChildren(
+                            new Framework.Controls.TemplateHost() { Template = itemTemplate },
+                            new HtmlGenericControl("p")
+                                .AppendChildren(
+                                    new LinkButton() { Text = "Remove" }
+                                        .SetProperty(
+                                            ButtonBase.ClickProperty,
+                                            new CommandBindingExpression(bindingCompilationService, contexts => {
+                                                    ((dynamic)dataSource.GetBindingValue(this)).Remove((dynamic)contexts[0]);
+                                                }, "564787DE-E882-4C2D-BA39-482D1AB8F0CD"))
+                                )
+                        )
+                    ),
+                    SeparatorTemplate = new DelegateTemplate(_ => new HtmlGenericControl("hr"))
+                }
+                .SetAttribute("class", "templated-list")
+                .SetProperty(ItemsControl.DataSourceProperty, dataSource);
+
+            yield return new HtmlGenericControl("p")
+                .AppendChildren(new Button() { Text = "Add item" }
+                    .SetProperty(
+                        ButtonBase.ClickProperty,
+                    new CommandBindingExpression(bindingCompilationService, contexts => {
+                                var item = onCreateItem.BindingDelegate(this.GetDataContexts().ToArray(), this);
+                                ((dynamic)dataSource.GetBindingValue(this)).Add(((dynamic)item)());
+                            }, "38921DE7-936D-4862-921A-5051DA0CAEB1")));
+        }
+
+    }
+}

src/Samples/Common/Views/ControlSamples/TemplateHost/TemplatedListControl.cs

@@ -0,0 +1,59 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using DotVVM.Framework.Binding;
+using DotVVM.Framework.Binding.Expressions;
+using DotVVM.Framework.Controls;
+
+namespace DotVVM.Samples.Common.Views.ControlSamples.TemplateHost
+{
+    public class TemplatedListControl : DotvvmMarkupControl
+    {
+
+        [MarkupOptions(AllowHardCodedValue = false, Required = true)]
+        public IEnumerable DataSource
+        {
+            get { return (IEnumerable)GetValue(DataSourceProperty); }
+            set { SetValue(DataSourceProperty, value); }
+        }
+        public static readonly DotvvmProperty DataSourceProperty
+            = DotvvmProperty.Register<IEnumerable, TemplatedListControl>(c => c.DataSource, null);
+
+        [ControlPropertyBindingDataContextChange(nameof(DataSource), order: 0)]
+        [CollectionElementDataContextChange(order: 1)]
+        [MarkupOptions(AllowBinding = false, Required = true, MappingMode = MappingMode.InnerElement)]
+        public ITemplate ItemTemplate
+        {
+            get { return (ITemplate)GetValue(ItemTemplateProperty); }
+            set { SetValue(ItemTemplateProperty, value); }
+        }
+        public static readonly DotvvmProperty ItemTemplateProperty
+            = DotvvmProperty.Register<ITemplate, TemplatedListControl>(c => c.ItemTemplate, null);
+
+        [MarkupOptions(AllowHardCodedValue = false, Required = true)]
+        public ICommandBinding<object> OnCreateItem
+        {
+            get { return (ICommandBinding<object>)GetValue(OnCreateItemProperty); }
+            set { SetValue(OnCreateItemProperty, value); }
+        }
+        public static readonly DotvvmProperty OnCreateItemProperty
+            = DotvvmProperty.Register<ICommandBinding<object>, TemplatedListControl>(c => c.OnCreateItem, null);
+
+
+        public void AddItem()
+        {
+            var item = OnCreateItem.BindingDelegate(this.GetDataContexts().ToArray(), this);
+            ((dynamic)DataSource).Add(((dynamic)item)());
+        }
+
+        public void RemoveItem(object item)
+        {
+            ((dynamic)DataSource).Remove((dynamic)item);
+        }
+
+    }
+
+}
+

src/Samples/Common/Views/ControlSamples/TemplateHost/TemplatedListControl.dotcontrol

@@ -0,0 +1,21 @@
+@viewModel System.Object, mscorlib
+@baseType DotVVM.Samples.Common.Views.ControlSamples.TemplateHost.TemplatedListControl, DotVVM.Samples.Common
+
+<dot:Repeater DataSource="{value: _control.DataSource}" class="templated-list">
+    <ItemTemplate>
+        <div>
+            <dot:TemplateHost Template="{resource: _control.ItemTemplate}" />
+
+            <p>
+                <dot:LinkButton Text="Remove" Click="{command: _control.RemoveItem(_this)}" />
+            </p>
+        </div>
+    </ItemTemplate>
+    <SeparatorTemplate>
+        <hr />
+    </SeparatorTemplate>
+</dot:Repeater>
+
+<p>
+    <dot:Button Text="Add item" Click="{command: _control.AddItem()}" />
+</p>

src/Samples/Common/Views/ControlSamples/TemplateHost/TemplatedMarkupControl.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using DotVVM.Framework.Binding;
+using DotVVM.Framework.Controls;
+
+namespace DotVVM.Samples.Common.Views.ControlSamples.TemplateHost
+{
+    public class TemplatedMarkupControl : DotvvmMarkupControl
+    {
+
+        public string HeaderText
+        {
+            get { return (string)GetValue(HeaderTextProperty); }
+            set { SetValue(HeaderTextProperty, value); }
+        }
+        public static readonly DotvvmProperty HeaderTextProperty
+            = DotvvmProperty.Register<string, TemplatedMarkupControl>(c => c.HeaderText, null);
+
+        [MarkupOptions(AllowBinding = false, MappingMode = MappingMode.InnerElement, Required = true)]
+        public ITemplate ContentTemplate
+        {
+            get { return (ITemplate)GetValue(ContentTemplateProperty); }
+            set { SetValue(ContentTemplateProperty, value); }
+        }
+        public static readonly DotvvmProperty ContentTemplateProperty
+            = DotvvmProperty.Register<ITemplate, TemplatedMarkupControl>(c => c.ContentTemplate, null);
+
+
+    }
+}
+

src/Samples/Common/Views/ControlSamples/TemplateHost/TemplatedMarkupControl.dotcontrol

@@ -0,0 +1,7 @@
+@viewModel System.Object, mscorlib
+@baseType DotVVM.Samples.Common.Views.ControlSamples.TemplateHost.TemplatedMarkupControl, DotVVM.Samples.Common
+
+<fieldset>
+    <legend>{{value: _control.HeaderText}}</legend>
+    <dot:TemplateHost Template="{resource: _control.ContentTemplate}" />
+</fieldset>