Add SectionName to SectionOutlet and SectionContent (#47221)

surayya-MS · web-flow · commit f7e68a870f82 · 2023-03-17T09:12:59.000-07:00
* Added SectionName to SectionOutlet and SectionContent
diff --git a/src/Components/Components/src/PublicAPI.Unshipped.txt b/src/Components/Components/src/PublicAPI.Unshipped.txt
@@ -9,12 +9,16 @@ Microsoft.AspNetCore.Components.Sections.SectionContent.ChildContent.get -> Micr
 Microsoft.AspNetCore.Components.Sections.SectionContent.ChildContent.set -> void
 Microsoft.AspNetCore.Components.Sections.SectionContent.Dispose() -> void
 Microsoft.AspNetCore.Components.Sections.SectionContent.SectionContent() -> void
-Microsoft.AspNetCore.Components.Sections.SectionContent.SectionId.get -> object!
+Microsoft.AspNetCore.Components.Sections.SectionContent.SectionId.get -> object?
 Microsoft.AspNetCore.Components.Sections.SectionContent.SectionId.set -> void
+Microsoft.AspNetCore.Components.Sections.SectionContent.SectionName.get -> string?
+Microsoft.AspNetCore.Components.Sections.SectionContent.SectionName.set -> void
 Microsoft.AspNetCore.Components.Sections.SectionOutlet
 Microsoft.AspNetCore.Components.Sections.SectionOutlet.Dispose() -> void
-Microsoft.AspNetCore.Components.Sections.SectionOutlet.SectionId.get -> object!
+Microsoft.AspNetCore.Components.Sections.SectionOutlet.SectionId.get -> object?
 Microsoft.AspNetCore.Components.Sections.SectionOutlet.SectionId.set -> void
+Microsoft.AspNetCore.Components.Sections.SectionOutlet.SectionName.get -> string?
+Microsoft.AspNetCore.Components.Sections.SectionOutlet.SectionName.set -> void
 Microsoft.AspNetCore.Components.Sections.SectionOutlet.SectionOutlet() -> void
 Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder.AddComponentParameter(int sequence, string! name, object? value) -> void
 override Microsoft.AspNetCore.Components.EventCallback.GetHashCode() -> int
diff --git a/src/Components/Components/src/Sections/SectionContent.cs b/src/Components/Components/src/Sections/SectionContent.cs
@@ -8,15 +8,21 @@ namespace Microsoft.AspNetCore.Components.Sections;
 /// </summary>
 public sealed class SectionContent : ISectionContentProvider, IComponent, IDisposable
 {
-    private object? _registeredSectionId;
+    private object? _registeredIdentifier;
     private bool? _registeredIsDefaultContent;
     private SectionRegistry _registry = default!;
 
     /// <summary>
-    /// Gets or sets the ID that determines which <see cref="SectionOutlet"/> instance will render
+    /// Gets or sets the <see cref="string"/> ID that determines which <see cref="SectionOutlet"/> instance will render
     /// the content of this instance.
     /// </summary>
-    [Parameter, EditorRequired] public object SectionId { get; set; } = default!;
+    [Parameter] public string? SectionName { get; set; }
+
+    /// <summary>
+    /// Gets or sets the <see cref="object"/> ID that determines which <see cref="SectionOutlet"/> instance will render
+    /// the content of this instance.
+    /// </summary>
+    [Parameter] public object? SectionId { get; set; }
 
     /// <summary>
     /// Gets or sets whether this component should provide the default content for the target
@@ -37,11 +43,56 @@ void IComponent.Attach(RenderHandle renderHandle)
     }
 
     Task IComponent.SetParametersAsync(ParameterView parameters)
+    {
+        // We are not using parameters.SetParameterProperties(this)
+        // because IsDefaultContent is internal property and not a parameter
+        SetParameterValues(parameters);
+
+        object? identifier;
+
+        if (SectionName is not null && SectionId is not null)
+        {
+            throw new InvalidOperationException($"{nameof(SectionContent)} requires that '{nameof(SectionName)}' and '{nameof(SectionId)}' cannot both have non-null values.");
+        }
+        else if (SectionName is not null)
+        {
+            identifier = SectionName;
+        }
+        else if (SectionId is not null)
+        {
+            identifier = SectionId;
+        }
+        else
+        {
+            throw new InvalidOperationException($"{nameof(SectionContent)} requires a non-null value either for '{nameof(SectionName)}' or '{nameof(SectionId)}'.");
+        }
+
+        if (!object.Equals(identifier, _registeredIdentifier) || IsDefaultContent != _registeredIsDefaultContent)
+        {
+            if (_registeredIdentifier is not null)
+            {
+                _registry.RemoveProvider(_registeredIdentifier, this);
+            }
+
+            _registry.AddProvider(identifier, this, IsDefaultContent);
+            _registeredIdentifier = SectionId;
+            _registeredIsDefaultContent = IsDefaultContent;
+        }
+
+        _registry.NotifyContentChanged(identifier, this);
+
+        return Task.CompletedTask;
+    }
+
+    private void SetParameterValues(in ParameterView parameters)
     {
         foreach (var param in parameters)
         {
             switch (param.Name)
             {
+                case nameof(SectionContent.SectionName):
+                    SectionName = (string)param.Value;
+                    break;
                 case nameof(SectionContent.SectionId):
                     SectionId = param.Value;
                     break;
@@ -55,35 +106,14 @@ Task IComponent.SetParametersAsync(ParameterView parameters)
                     throw new ArgumentException($"Unknown parameter '{param.Name}'");
             }
         }
-
-        if (SectionId is null)
-        {
-            throw new InvalidOperationException($"{nameof(SectionContent)} requires a non-null value for the parameter '{nameof(SectionId)}'.");
-        }
-
-        if (!object.Equals(SectionId, _registeredSectionId) || IsDefaultContent != _registeredIsDefaultContent)
-        {
-            if (_registeredSectionId is not null)
-            {
-                _registry.RemoveProvider(_registeredSectionId, this);
-            }
-
-            _registry.AddProvider(SectionId, this, IsDefaultContent);
-            _registeredSectionId = SectionId;
-            _registeredIsDefaultContent = IsDefaultContent;
-        }
-
-        _registry.NotifyContentChanged(SectionId, this);
-
-        return Task.CompletedTask;
     }
 
     /// <inheritdoc/>
     public void Dispose()
     {
-        if (_registeredSectionId is not null)
+        if (_registeredIdentifier is not null)
         {
-            _registry.RemoveProvider(_registeredSectionId, this);
+            _registry.RemoveProvider(_registeredIdentifier, this);
         }
     }
 }
diff --git a/src/Components/Components/src/Sections/SectionOutlet.cs b/src/Components/Components/src/Sections/SectionOutlet.cs
@@ -10,16 +10,22 @@ public sealed class SectionOutlet : ISectionContentSubscriber, IComponent, IDisp
 {
     private static readonly RenderFragment _emptyRenderFragment = _ => { };
 
-    private object? _subscribedSectionId;
+    private object? _subscribedIdentifier;
     private RenderHandle _renderHandle;
     private SectionRegistry _registry = default!;
     private RenderFragment? _content;
 
     /// <summary>
-    /// Gets or sets the ID that determines which <see cref="SectionContent"/> instances will provide
+    /// Gets or sets the <see cref="string"/> ID that determines which <see cref="SectionContent"/> instances will provide
     /// content to this instance.
     /// </summary>
-    [Parameter, EditorRequired] public object SectionId { get; set; } = default!;
+    [Parameter] public string? SectionName { get; set; }
+
+    /// <summary>
+    /// Gets or sets the <see cref="object"/> ID that determines which <see cref="SectionContent"/> instances will provide
+    /// content to this instance.
+    /// </summary>
+    [Parameter] public object? SectionId { get; set; }
 
     void IComponent.Attach(RenderHandle renderHandle)
     {
@@ -31,20 +37,34 @@ Task IComponent.SetParametersAsync(ParameterView parameters)
     {
         parameters.SetParameterProperties(this);
 
-        if (SectionId is null)
+        object? identifier;
+
+        if (SectionName is not null && SectionId is not null)
+        {
+            throw new InvalidOperationException($"{nameof(SectionOutlet)} requires that '{nameof(SectionName)}' and '{nameof(SectionId)}' cannot both have non-null values.");
+        }
+        else if (SectionName is not null)
+        {
+            identifier = SectionName;
+        }
+        else if (SectionId is not null)
+        {
+            identifier = SectionId;
+        }
+        else
         {
-            throw new InvalidOperationException($"{nameof(SectionOutlet)} requires a non-null value for the parameter '{nameof(SectionId)}'.");
+            throw new InvalidOperationException($"{nameof(SectionOutlet)} requires a non-null value either for '{nameof(SectionName)}' or '{nameof(SectionId)}'.");
         }
 
-        if (!object.Equals(SectionId, _subscribedSectionId))
+        if (!object.Equals(identifier, _subscribedIdentifier))
         {
-            if (_subscribedSectionId is not null)
+            if (_subscribedIdentifier is not null)
             {
-                _registry.Unsubscribe(_subscribedSectionId);
+                _registry.Unsubscribe(_subscribedIdentifier);
             }
 
-            _registry.Subscribe(SectionId, this);
-            _subscribedSectionId = SectionId;
+            _registry.Subscribe(identifier, this);
+            _subscribedIdentifier = SectionId;
         }
 
         RenderContent();
@@ -74,9 +94,9 @@ private void RenderContent()
     /// <inheritdoc/>
     public void Dispose()
     {
-        if (_subscribedSectionId is not null)
+        if (_subscribedIdentifier is not null)
         {
-            _registry.Unsubscribe(_subscribedSectionId);
+            _registry.Unsubscribe(_subscribedIdentifier);
         }
     }
 }
diff --git a/src/Components/Components/src/Sections/SectionRegistry.cs b/src/Components/Components/src/Sections/SectionRegistry.cs
@@ -5,15 +5,15 @@ namespace Microsoft.AspNetCore.Components.Sections;
 
 internal sealed class SectionRegistry
 {
-    private readonly Dictionary<object, ISectionContentSubscriber> _subscribersBySectionId = new();
-    private readonly Dictionary<object, List<ISectionContentProvider>> _providersBySectionId = new();
+    private readonly Dictionary<object, ISectionContentSubscriber> _subscribersByIdentifier = new();
+    private readonly Dictionary<object, List<ISectionContentProvider>> _providersByIdentifier = new();
 
-    public void AddProvider(object sectionId, ISectionContentProvider provider, bool isDefaultProvider)
+    public void AddProvider(object identifier, ISectionContentProvider provider, bool isDefaultProvider)
     {
-        if (!_providersBySectionId.TryGetValue(sectionId, out var providers))
+        if (!_providersByIdentifier.TryGetValue(identifier, out var providers))
         {
             providers = new();
-            _providersBySectionId.Add(sectionId, providers);
+            _providersByIdentifier.Add(identifier, providers);
         }
 
         if (isDefaultProvider)
@@ -26,18 +26,18 @@ public void AddProvider(object sectionId, ISectionContentProvider provider, bool
         }
     }
 
-    public void RemoveProvider(object sectionId, ISectionContentProvider provider)
+    public void RemoveProvider(object identifier, ISectionContentProvider provider)
     {
-        if (!_providersBySectionId.TryGetValue(sectionId, out var providers))
+        if (!_providersByIdentifier.TryGetValue(identifier, out var providers))
         {
-            throw new InvalidOperationException($"There are no content providers with the given section ID '{sectionId}'.");
+            throw new InvalidOperationException($"There are no content providers with the given section ID '{identifier}'.");
         }
 
         var index = providers.LastIndexOf(provider);
 
         if (index < 0)
         {
-            throw new InvalidOperationException($"The provider was not found in the providers list of the given section ID '{sectionId}'.");
+            throw new InvalidOperationException($"The provider was not found in the providers list of the given section ID '{identifier}'.");
         }
 
         providers.RemoveAt(index);
@@ -47,44 +47,44 @@ public void RemoveProvider(object sectionId, ISectionContentProvider provider)
             // We just removed the most recently added provider, meaning we need to change
             // the current content to that of second most recently added provider.
             var content = GetCurrentProviderContentOrDefault(providers);
-            NotifyContentChangedForSubscriber(sectionId, content);
+            NotifyContentChangedForSubscriber(identifier, content);
         }
     }
 
-    public void Subscribe(object sectionId, ISectionContentSubscriber subscriber)
+    public void Subscribe(object identifier, ISectionContentSubscriber subscriber)
     {
-        if (_subscribersBySectionId.ContainsKey(sectionId))
+        if (_subscribersByIdentifier.ContainsKey(identifier))
         {
-            throw new InvalidOperationException($"There is already a subscriber to the content with the given section ID '{sectionId}'.");
+            throw new InvalidOperationException($"There is already a subscriber to the content with the given section ID '{identifier}'.");
         }
 
         // Notify the new subscriber with any existing content.
-        var content = GetCurrentProviderContentOrDefault(sectionId);
+        var content = GetCurrentProviderContentOrDefault(identifier);
         subscriber.ContentChanged(content);
 
-        _subscribersBySectionId.Add(sectionId, subscriber);
+        _subscribersByIdentifier.Add(identifier, subscriber);
     }
 
-    public void Unsubscribe(object sectionId)
+    public void Unsubscribe(object identifier)
     {
-        if (!_subscribersBySectionId.Remove(sectionId))
+        if (!_subscribersByIdentifier.Remove(identifier))
         {
-            throw new InvalidOperationException($"The subscriber with the given section ID '{sectionId}' is already unsubscribed.");
+            throw new InvalidOperationException($"The subscriber with the given section ID '{identifier}' is already unsubscribed.");
         }
     }
 
-    public void NotifyContentChanged(object sectionId, ISectionContentProvider provider)
+    public void NotifyContentChanged(object identifier, ISectionContentProvider provider)
     {
-        if (!_providersBySectionId.TryGetValue(sectionId, out var providers))
+        if (!_providersByIdentifier.TryGetValue(identifier, out var providers))
         {
-            throw new InvalidOperationException($"There are no content providers with the given section ID '{sectionId}'.");
+            throw new InvalidOperationException($"There are no content providers with the given section ID '{identifier}'.");
         }
 
         // We only notify content changed for subscribers when the content of the
         // most recently added provider changes.
         if (providers.Count != 0 && providers[^1] == provider)
         {
-            NotifyContentChangedForSubscriber(sectionId, provider.Content);
+            NotifyContentChangedForSubscriber(identifier, provider.Content);
         }
     }
 
@@ -93,14 +93,14 @@ public void NotifyContentChanged(object sectionId, ISectionContentProvider provi
             ? providers[^1].Content
             : null;
 
-    private RenderFragment? GetCurrentProviderContentOrDefault(object sectionId)
-        => _providersBySectionId.TryGetValue(sectionId, out var existingList)
+    private RenderFragment? GetCurrentProviderContentOrDefault(object identifier)
+        => _providersByIdentifier.TryGetValue(identifier, out var existingList)
             ? GetCurrentProviderContentOrDefault(existingList)
             : null;
 
-    private void NotifyContentChangedForSubscriber(object sectionId, RenderFragment? content)
+    private void NotifyContentChangedForSubscriber(object identifier, RenderFragment? content)
     {
-        if (_subscribersBySectionId.TryGetValue(sectionId, out var subscriber))
+        if (_subscribersByIdentifier.TryGetValue(identifier, out var subscriber))
         {
             subscriber.ContentChanged(content);
         }
diff --git a/src/Components/test/E2ETest/Tests/SectionsTest.cs b/src/Components/test/E2ETest/Tests/SectionsTest.cs
diff --git a/src/Components/test/testassets/BasicTestApp/SectionsTest/ParentComponentWithTwoChildren.razor b/src/Components/test/testassets/BasicTestApp/SectionsTest/ParentComponentWithTwoChildren.razor

Original file line number	Diff line number	Diff line change
`@@ -10,16 +10,22 @@ public sealed class SectionOutlet : ISectionContentSubscriber, IComponent, IDisp`
`10`	`10`	`{`
`11`	`11`	`private static readonly RenderFragment _emptyRenderFragment = _ => { };`
`12`	`12`
`13`		`- private object? _subscribedSectionId;`
	`13`	`+ private object? _subscribedIdentifier;`
`14`	`14`	`private RenderHandle _renderHandle;`
`15`	`15`	`private SectionRegistry _registry = default!;`
`16`	`16`	`private RenderFragment? _content;`
`17`	`17`
`18`	`18`	`/// <summary>`
`19`		`- /// Gets or sets the ID that determines which <see cref="SectionContent"/> instances will provide`
	`19`	`+ /// Gets or sets the <see cref="string"/> ID that determines which <see cref="SectionContent"/> instances will provide`
`20`	`20`	`/// content to this instance.`
`21`	`21`	`/// </summary>`
`22`		`- [Parameter, EditorRequired] public object SectionId { get; set; } = default!;`
	`22`	`+ [Parameter] public string? SectionName { get; set; }`
	`23`	`+`
	`24`	`+ /// <summary>`
	`25`	`+ /// Gets or sets the <see cref="object"/> ID that determines which <see cref="SectionContent"/> instances will provide`
	`26`	`+ /// content to this instance.`
	`27`	`+ /// </summary>`
	`28`	`+ [Parameter] public object? SectionId { get; set; }`
`23`	`29`
`24`	`30`	`void IComponent.Attach(RenderHandle renderHandle)`
`25`	`31`	`{`
`@@ -31,20 +37,34 @@ Task IComponent.SetParametersAsync(ParameterView parameters)`
`31`	`37`	`{`
`32`	`38`	`parameters.SetParameterProperties(this);`
`33`	`39`
`34`		`- if (SectionId is null)`
	`40`	`+ object? identifier;`
	`41`	`+`
	`42`	`+ if (SectionName is not null && SectionId is not null)`
	`43`	`+ {`
	`44`	`+ throw new InvalidOperationException($"{nameof(SectionOutlet)} requires that '{nameof(SectionName)}' and '{nameof(SectionId)}' cannot both have non-null values.");`
	`45`	`+ }`
	`46`	`+ else if (SectionName is not null)`
	`47`	`+ {`
	`48`	`+ identifier = SectionName;`
	`49`	`+ }`
	`50`	`+ else if (SectionId is not null)`
	`51`	`+ {`
	`52`	`+ identifier = SectionId;`
	`53`	`+ }`
	`54`	`+ else`
`35`	`55`	`{`
`36`		`- throw new InvalidOperationException($"{nameof(SectionOutlet)} requires a non-null value for the parameter '{nameof(SectionId)}'.");`
	`56`	`+ throw new InvalidOperationException($"{nameof(SectionOutlet)} requires a non-null value either for '{nameof(SectionName)}' or '{nameof(SectionId)}'.");`
`37`	`57`	`}`
`38`	`58`
`39`		`- if (!object.Equals(SectionId, _subscribedSectionId))`
	`59`	`+ if (!object.Equals(identifier, _subscribedIdentifier))`
`40`	`60`	`{`
`41`		`- if (_subscribedSectionId is not null)`
	`61`	`+ if (_subscribedIdentifier is not null)`
`42`	`62`	`{`
`43`		`- _registry.Unsubscribe(_subscribedSectionId);`
	`63`	`+ _registry.Unsubscribe(_subscribedIdentifier);`
`44`	`64`	`}`
`45`	`65`
`46`		`- _registry.Subscribe(SectionId, this);`
`47`		`- _subscribedSectionId = SectionId;`
	`66`	`+ _registry.Subscribe(identifier, this);`
	`67`	`+ _subscribedIdentifier = SectionId;`
`48`	`68`	`}`
`49`	`69`
`50`	`70`	`RenderContent();`
`@@ -74,9 +94,9 @@ private void RenderContent()`
`74`	`94`	`/// <inheritdoc/>`
`75`	`95`	`public void Dispose()`
`76`	`96`	`{`
`77`		`- if (_subscribedSectionId is not null)`
	`97`	`+ if (_subscribedIdentifier is not null)`
`78`	`98`	`{`
`79`		`- _registry.Unsubscribe(_subscribedSectionId);`
	`99`	`+ _registry.Unsubscribe(_subscribedIdentifier);`
`80`	`100`	`}`
`81`	`101`	`}`
`82`	`102`	`}`
Original file line number	Diff line number	Diff line change
`@@ -5,15 +5,15 @@ namespace Microsoft.AspNetCore.Components.Sections;`
`5`	`5`
`6`	`6`	`internal sealed class SectionRegistry`
`7`	`7`	`{`
`8`		`- private readonly Dictionary<object, ISectionContentSubscriber> _subscribersBySectionId = new();`
`9`		`- private readonly Dictionary<object, List<ISectionContentProvider>> _providersBySectionId = new();`
	`8`	`+ private readonly Dictionary<object, ISectionContentSubscriber> _subscribersByIdentifier = new();`
	`9`	`+ private readonly Dictionary<object, List<ISectionContentProvider>> _providersByIdentifier = new();`
`10`	`10`
`11`		`- public void AddProvider(object sectionId, ISectionContentProvider provider, bool isDefaultProvider)`
	`11`	`+ public void AddProvider(object identifier, ISectionContentProvider provider, bool isDefaultProvider)`
`12`	`12`	`{`
`13`		`- if (!_providersBySectionId.TryGetValue(sectionId, out var providers))`
	`13`	`+ if (!_providersByIdentifier.TryGetValue(identifier, out var providers))`
`14`	`14`	`{`
`15`	`15`	`providers = new();`
`16`		`- _providersBySectionId.Add(sectionId, providers);`
	`16`	`+ _providersByIdentifier.Add(identifier, providers);`
`17`	`17`	`}`
`18`	`18`
`19`	`19`	`if (isDefaultProvider)`
`@@ -26,18 +26,18 @@ public void AddProvider(object sectionId, ISectionContentProvider provider, bool`
`26`	`26`	`}`
`27`	`27`	`}`
`28`	`28`
`29`		`- public void RemoveProvider(object sectionId, ISectionContentProvider provider)`
	`29`	`+ public void RemoveProvider(object identifier, ISectionContentProvider provider)`
`30`	`30`	`{`
`31`		`- if (!_providersBySectionId.TryGetValue(sectionId, out var providers))`
	`31`	`+ if (!_providersByIdentifier.TryGetValue(identifier, out var providers))`
`32`	`32`	`{`
`33`		`- throw new InvalidOperationException($"There are no content providers with the given section ID '{sectionId}'.");`
	`33`	`+ throw new InvalidOperationException($"There are no content providers with the given section ID '{identifier}'.");`
`34`	`34`	`}`
`35`	`35`
`36`	`36`	`var index = providers.LastIndexOf(provider);`
`37`	`37`
`38`	`38`	`if (index < 0)`
`39`	`39`	`{`
`40`		`- throw new InvalidOperationException($"The provider was not found in the providers list of the given section ID '{sectionId}'.");`
	`40`	`+ throw new InvalidOperationException($"The provider was not found in the providers list of the given section ID '{identifier}'.");`
`41`	`41`	`}`
`42`	`42`
`43`	`43`	`providers.RemoveAt(index);`
`@@ -47,44 +47,44 @@ public void RemoveProvider(object sectionId, ISectionContentProvider provider)`
`47`	`47`	`// We just removed the most recently added provider, meaning we need to change`
`48`	`48`	`// the current content to that of second most recently added provider.`
`49`	`49`	`var content = GetCurrentProviderContentOrDefault(providers);`
`50`		`- NotifyContentChangedForSubscriber(sectionId, content);`
	`50`	`+ NotifyContentChangedForSubscriber(identifier, content);`
`51`	`51`	`}`
`52`	`52`	`}`
`53`	`53`
`54`		`- public void Subscribe(object sectionId, ISectionContentSubscriber subscriber)`
	`54`	`+ public void Subscribe(object identifier, ISectionContentSubscriber subscriber)`
`55`	`55`	`{`
`56`		`- if (_subscribersBySectionId.ContainsKey(sectionId))`
	`56`	`+ if (_subscribersByIdentifier.ContainsKey(identifier))`
`57`	`57`	`{`
`58`		`- throw new InvalidOperationException($"There is already a subscriber to the content with the given section ID '{sectionId}'.");`
	`58`	`+ throw new InvalidOperationException($"There is already a subscriber to the content with the given section ID '{identifier}'.");`
`59`	`59`	`}`
`60`	`60`
`61`	`61`	`// Notify the new subscriber with any existing content.`
`62`		`- var content = GetCurrentProviderContentOrDefault(sectionId);`
	`62`	`+ var content = GetCurrentProviderContentOrDefault(identifier);`
`63`	`63`	`subscriber.ContentChanged(content);`
`64`	`64`
`65`		`- _subscribersBySectionId.Add(sectionId, subscriber);`
	`65`	`+ _subscribersByIdentifier.Add(identifier, subscriber);`
`66`	`66`	`}`
`67`	`67`
`68`		`- public void Unsubscribe(object sectionId)`
	`68`	`+ public void Unsubscribe(object identifier)`
`69`	`69`	`{`
`70`		`- if (!_subscribersBySectionId.Remove(sectionId))`
	`70`	`+ if (!_subscribersByIdentifier.Remove(identifier))`
`71`	`71`	`{`
`72`		`- throw new InvalidOperationException($"The subscriber with the given section ID '{sectionId}' is already unsubscribed.");`
	`72`	`+ throw new InvalidOperationException($"The subscriber with the given section ID '{identifier}' is already unsubscribed.");`
`73`	`73`	`}`
`74`	`74`	`}`
`75`	`75`
`76`		`- public void NotifyContentChanged(object sectionId, ISectionContentProvider provider)`
	`76`	`+ public void NotifyContentChanged(object identifier, ISectionContentProvider provider)`
`77`	`77`	`{`
`78`		`- if (!_providersBySectionId.TryGetValue(sectionId, out var providers))`
	`78`	`+ if (!_providersByIdentifier.TryGetValue(identifier, out var providers))`
`79`	`79`	`{`
`80`		`- throw new InvalidOperationException($"There are no content providers with the given section ID '{sectionId}'.");`
	`80`	`+ throw new InvalidOperationException($"There are no content providers with the given section ID '{identifier}'.");`
`81`	`81`	`}`
`82`	`82`
`83`	`83`	`// We only notify content changed for subscribers when the content of the`
`84`	`84`	`// most recently added provider changes.`
`85`	`85`	`if (providers.Count != 0 && providers[^1] == provider)`
`86`	`86`	`{`
`87`		`- NotifyContentChangedForSubscriber(sectionId, provider.Content);`
	`87`	`+ NotifyContentChangedForSubscriber(identifier, provider.Content);`
`88`	`88`	`}`
`89`	`89`	`}`
`90`	`90`
`@@ -93,14 +93,14 @@ public void NotifyContentChanged(object sectionId, ISectionContentProvider provi`
`93`	`93`	`? providers[^1].Content`
`94`	`94`	`: null;`
`95`	`95`
`96`		`- private RenderFragment? GetCurrentProviderContentOrDefault(object sectionId)`
`97`		`- => _providersBySectionId.TryGetValue(sectionId, out var existingList)`
	`96`	`+ private RenderFragment? GetCurrentProviderContentOrDefault(object identifier)`
	`97`	`+ => _providersByIdentifier.TryGetValue(identifier, out var existingList)`
`98`	`98`	`? GetCurrentProviderContentOrDefault(existingList)`
`99`	`99`	`: null;`
`100`	`100`
`101`		`- private void NotifyContentChangedForSubscriber(object sectionId, RenderFragment? content)`
	`101`	`+ private void NotifyContentChangedForSubscriber(object identifier, RenderFragment? content)`
`102`	`102`	`{`
`103`		`- if (_subscribersBySectionId.TryGetValue(sectionId, out var subscriber))`
	`103`	`+ if (_subscribersByIdentifier.TryGetValue(identifier, out var subscriber))`
`104`	`104`	`{`
`105`	`105`	`subscriber.ContentChanged(content);`
`106`	`106`	`}`