Initial structures for enabling click events to be routed from JS to …

…Blazorade Mermaid.

Blazorade.Mermaid/Components/MermaidDiagram.razor.cs

@@ -1,4 +1,5 @@
-using Microsoft.AspNetCore.Components;
+using Blazorade.Mermaid.Model;
+using Microsoft.AspNetCore.Components;
 using Microsoft.JSInterop;
 using System;
 using System.Collections.Generic;
@@ -17,7 +18,7 @@ namespace Blazorade.Mermaid.Components
     /// For more information on Mermaid and what kind of diagrams you can display with it, please
     /// refer to https://mermaid.js.org/
     /// </remarks>
-    partial class MermaidDiagram
+    partial class MermaidDiagram : IAsyncDisposable
     {
         /// <summary>
         /// The Mermaid definition to render as a diagram.
@@ -61,14 +62,27 @@ destroy B
         [Parameter]
         public string? Id { get; set; }
 
+        /// <inheritdoc/>
+        public async ValueTask DisposeAsync()
+        {
+        }
+
+        /// <summary>
+        /// The callback method that will be called by Mermaid JS when a diagram element is clicked.
+        /// </summary>
+        [JSInvokable]
+        public async Task OnElementClickCallbackAsync(ElementClickCallbackArgs args)
+        {
+
+        }
+
         [Inject]
         private IJSRuntime JSRuntime { get; set; } = null!;
 
         /// <inheritdoc/>
         protected async override Task OnAfterRenderAsync(bool firstRender)
         {
-            var jsModule = await this.GetBlazoradeMermaidModuleAsync();
-            await jsModule.InvokeVoidAsync("run", this.Id, this.Definition);
+            await this.UpdateDiagramAsync();
         }
 
         /// <inheritdoc/>
@@ -96,5 +110,19 @@ private void SetIdIfEmpty(string? id = null)
                 this.Attributes.Add("id", id);
             }
         }
+
+        private async ValueTask RegisterClickCallbacksAsync()
+        {
+
+        }
+
+        private async ValueTask UpdateDiagramAsync()
+        {
+            var jsModule = await this.GetBlazoradeMermaidModuleAsync();
+            await jsModule.InvokeVoidAsync("run", this.Id, this.Definition);
+
+            await this.RegisterClickCallbacksAsync();
+        }
+
     }
 }

Blazorade.Mermaid/Model/ElementClickCallbackArgs.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Blazorade.Mermaid.Model
+{
+    /// <summary>
+    /// Callback arguments for when a diagram element is clicked.
+    /// </summary>
+    public class ElementClickCallbackArgs
+    {
+        /// <summary>
+        /// The Mermaid ID of the element that was clicked.
+        /// </summary>
+        public string Id { get; set; } = string.Empty;
+
+    }
+}