Add extentions for ContentImporter.

src/cs/MonoGame.Extended.Content.Pipeline/ContentImporterContextExtensions.cs

@@ -0,0 +1,15 @@
+using System.IO;
+using Microsoft.Xna.Framework.Content.Pipeline;
+
+namespace MonoGame.Extended.Content.Pipeline;
+
+public static class ContentImporterContextExtensions
+{
+    public static string AddDependencyWithLogging(this ContentImporterContext context, string filePath, string source)
+    {
+        source = Path.Combine(Path.GetDirectoryName(filePath), source);
+        ContentLogger.Log($"Adding dependency '{source}'");
+        context.AddDependency(source);
+        return source;
+    }
+}

src/cs/MonoGame.Extended.Content.Pipeline/Tiled/TiledMapTilesetImporter.cs

@@ -39,23 +39,18 @@ namespace MonoGame.Extended.Content.Pipeline.Tiled
 				var tilesetSerializer = new XmlSerializer(typeof(TiledMapTilesetContent));
 				var tileset = (TiledMapTilesetContent)tilesetSerializer.Deserialize(reader);
 
-                tileset.Image.Source = Path.Combine(Path.GetDirectoryName(filePath), tileset.Image.Source);
-                ContentLogger.Log($"Adding dependency '{tileset.Image.Source}'");
-				context.AddDependency(tileset.Image.Source);
+                if (tileset.Image is not null)
+                    tileset.Image.Source = context.AddDependencyWithLogging(filePath, tileset.Image.Source);
 
 				foreach (var tile in tileset.Tiles)
 				{
 				    foreach (var obj in tile.Objects)
 				    {
 				        if (!string.IsNullOrWhiteSpace(obj.TemplateSource))
-				        {
-				            obj.TemplateSource = Path.Combine(Path.GetDirectoryName(filePath), obj.TemplateSource);
-                            ContentLogger.Log($"Adding dependency '{obj.TemplateSource}'");
-
-				            // We depend on the template.
-				            context.AddDependency(obj.TemplateSource);
-				        }
+                            obj.TemplateSource = context.AddDependencyWithLogging(filePath, obj.TemplateSource);
 				    }
+                    if (tile.Image is not null)
+                        tile.Image.Source = context.AddDependencyWithLogging(filePath, tile.Image.Source);
 				}
 
 			    return tileset;