intercept event handler exceptions (#179)

1 files changed, 65 insertions, 0 deletions

diff --git a/src/StardewModdingAPI/Framework/InternalExtensions.cs b/src/StardewModdingAPI/Framework/InternalExtensions.cs
new file mode 100644
index 00000000..d08d12f3
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/InternalExtensions.cs
@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace StardewModdingAPI.Framework
+{
+    /// <summary>Provides extension methods for SMAPI's internal use.</summary>
+    internal static class InternalExtensions
+    {
+        /*********
+        ** Public methods
+        *********/
+        /****
+        ** IMonitor
+        ****/
+        /// <summary>Safely raise an <see cref="EventHandler"/> event, and intercept any exceptions thrown by its handlers.</summary>
+        /// <param name="monitor">Encapsulates monitoring and logging.</param>
+        /// <param name="name">The event name for error messages.</param>
+        /// <param name="handlers">The event handlers.</param>
+        /// <param name="sender">The event sender.</param>
+        /// <param name="args">The event arguments (or <c>null</c> to pass <see cref="EventArgs.Empty"/>).</param>
+        public static void SafelyRaisePlainEvent(this IMonitor monitor, string name, IEnumerable<Delegate> handlers, object sender = null, EventArgs args = null)
+        {
+            if (handlers == null)
+                return;
+
+            foreach (EventHandler handler in Enumerable.Cast<EventHandler>(handlers))
+            {
+                try
+                {
+                    handler.Invoke(sender, args ?? EventArgs.Empty);
+                }
+                catch (Exception ex)
+                {
+                    monitor.Log($"A mod failed handling the {name} event:\n{ex}", LogLevel.Error);
+                }
+            }
+        }
+
+        /// <summary>Safely raise an <see cref="EventHandler{TEventArgs}"/> event, and intercept any exceptions thrown by its handlers.</summary>
+        /// <typeparam name="TEventArgs">The event argument object type.</typeparam>
+        /// <param name="monitor">Encapsulates monitoring and logging.</param>
+        /// <param name="name">The event name for error messages.</param>
+        /// <param name="handlers">The event handlers.</param>
+        /// <param name="sender">The event sender.</param>
+        /// <param name="args">The event arguments.</param>
+        public static void SafelyRaiseGenericEvent<TEventArgs>(this IMonitor monitor, string name, IEnumerable<Delegate> handlers, object sender, TEventArgs args)
+        {
+            if (handlers == null)
+                return;
+
+            foreach (EventHandler<TEventArgs> handler in Enumerable.Cast<EventHandler<TEventArgs>>(handlers))
+            {
+                try
+                {
+                    handler.Invoke(sender, args);
+                }
+                catch (Exception ex)
+                {
+                    monitor.Log($"A mod failed handling the {name} event:\n{ex}", LogLevel.Error);
+                }
+            }
+        }
+    }
+}