From 0a5bb6948662c23a8222d3967514e5669eaaa782 Mon Sep 17 00:00:00 2001
From: CloneTrooper1019 <clonet1019@gmail.com>
Date: Sun, 6 Oct 2019 02:18:42 -0500
Subject: [PATCH] Improvements and bug fixes

- Added some more methods to the Instance class to make instance queries
more powerful.
- Fixed a bug where comment nodes were being processed by the
XmlFileReader
---
 Tree/Instance.cs              | 50 ++++++++++++++++++++++++++++++++---
 XmlFormat/IO/XmlFileReader.cs |  3 +++
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/Tree/Instance.cs b/Tree/Instance.cs
index 99389df..2f297f3 100644
--- a/Tree/Instance.cs
+++ b/Tree/Instance.cs
@@ -131,6 +131,22 @@ namespace RobloxFiles
             return classType.IsAssignableFrom(myType);
         }
 
+        /// <summary>
+        /// Attempts to cast this Instance to an inherited class of type '<typeparamref name="T"/>'.
+        /// Returns null if the instance cannot be casted to the provided type.
+        /// </summary>
+        /// <typeparam name="T">The type of Instance to cast to.</typeparam>
+        /// <returns>The instance as the type '<typeparamref name="T"/>' if it can be converted, or null.</returns>
+        public T Cast<T>() where T : Instance
+        {
+            T result = null;
+
+            if (IsA<T>())
+                result = this as T;
+
+            return result;
+        }
+
         /// <summary>
         /// The parent of this Instance, or null if the instance is the root of a tree.<para/>
         /// Setting the value of this property will throw an exception if:<para/>
@@ -163,7 +179,7 @@ namespace RobloxFiles
         }
 
         /// <summary>
-        /// Returns a snapshot of the Instances currently parented to this Instance, as an array.
+        /// Returns an array containing all the children of this Instance.
         /// </summary>
         public Instance[] GetChildren()
         {
@@ -171,7 +187,20 @@ namespace RobloxFiles
         }
 
         /// <summary>
-        /// Returns a snapshot of the Instances that are descendants of this Instance, as an array.
+        /// Returns an array containing all the children of this Instance, whose type is '<typeparamref name="T"/>'.
+        /// </summary>
+        public T[] GetChildrenOfType<T>() where T : Instance
+        {
+            T[] ofType = GetChildren()
+                .Where(child => child.IsA<T>())
+                .Cast<T>()
+                .ToArray();
+
+            return ofType;
+        }
+
+        /// <summary>
+        /// Returns an array containing all the descendants of this Instance.
         /// </summary>
         public Instance[] GetDescendants()
         {
@@ -190,6 +219,19 @@ namespace RobloxFiles
             return results.ToArray();
         }
 
+        /// <summary>
+        /// Returns an array containing all the descendants of this Instance, whose type is '<typeparamref name="T"/>'.
+        /// </summary>
+        public T[] GetDescendantsOfType<T>() where T : Instance
+        {
+            T[] ofType = GetDescendants()
+                .Where(desc => desc.IsA<T>())
+                .Cast<T>()
+                .ToArray();
+
+            return ofType;
+        }
+
         /// <summary>
         /// Returns the first child of this Instance whose Name is the provided string name.
         /// If the instance is not found, this returns null.
@@ -291,7 +333,7 @@ namespace RobloxFiles
         }
 
         /// <summary>
-        /// Returns the first ancestor of this Instance which derives from the provided type T.
+        /// Returns the first ancestor of this Instance which derives from the provided type <typeparamref name="T"/>.
         /// If the instance is not found, this returns null.
         /// </summary>
         /// <param name="name">The Name of the Instance to find.</param>
@@ -349,7 +391,7 @@ namespace RobloxFiles
         }
 
         /// <summary>
-        /// Returns the first child of this Instance which derives from the provided type T.
+        /// Returns the first child of this Instance which derives from the provided type <typeparamref name="T"/>.
         /// If the instance is not found, this returns null.
         /// </summary>
         /// <param name="recursive">Whether this should search descendants as well.</param>
diff --git a/XmlFormat/IO/XmlFileReader.cs b/XmlFormat/IO/XmlFileReader.cs
index 377dc4c..aa1e908 100644
--- a/XmlFormat/IO/XmlFileReader.cs
+++ b/XmlFormat/IO/XmlFileReader.cs
@@ -75,6 +75,9 @@ namespace RobloxFiles.XmlFormat
 
             foreach (XmlNode propNode in propsNode.ChildNodes)
             {
+                if (propNode.NodeType == XmlNodeType.Comment)
+                    continue;
+
                 string propType = propNode.Name;
                 XmlNode propName = propNode.Attributes.GetNamedItem("name");