Add --delete flag to aid trimming worlds

NBTUtil/ConsoleOptions.cs

@@ -11,6 +11,7 @@ public enum ConsoleCommand
         Print,
         PrintTree,
         SetValue,
+        DeleteValue,
         SetList,
         Json,
         Help,
@@ -55,6 +56,7 @@ public ConsoleOptions ()
                     if (!string.IsNullOrEmpty(v))
                         Values.Add(v);
                 }},
+                { "delete", "Delete the NBT tag if found", v => Command = ConsoleCommand.DeleteValue },
                 { "help", "Print this help message", v => Command = ConsoleCommand.Help },
                 { "<>", v => {
                     switch (_currentKey) {

NBTUtil/ConsoleRunner.cs

@@ -13,6 +13,7 @@ class ConsoleRunner
     {
         private static readonly Dictionary<ConsoleCommand, ConsoleOperation> _commandTable = new Dictionary<ConsoleCommand, ConsoleOperation>() {
             { ConsoleCommand.SetValue, new EditOperation() },
+            { ConsoleCommand.DeleteValue, new DeleteOperation() },
             { ConsoleCommand.SetList, new SetListOperation() },
             { ConsoleCommand.Print, new PrintOperation() },
             { ConsoleCommand.PrintTree, new PrintTreeOperation() },
@@ -28,6 +29,8 @@ public ConsoleRunner ()
 
         public bool Run (string[] args)
         {
+            // Parse and validate command line arguments.
+
             _options.Parse(args);
 
             if (_options.Command == ConsoleCommand.Help)
@@ -45,20 +48,47 @@ public bool Run (string[] args)
             int successCount = 0;
             int failCount = 0;
 
-            foreach (var targetNode in new NbtPathEnumerator(_options.Path)) {
-                if (!op.CanProcess(targetNode)) {
-                    Console.WriteLine(targetNode.NodePath + ": ERROR (invalid command)");
-                    failCount++;
+            var nodesToProcess = new List<DataNode>();
+
+            // Iterate over all nodes matching the provided Path and create a list of the ones that can be processed
+            // using the provided ConsoleCommand.
+
+            foreach (var node in new NbtPathEnumerator(_options.Path))
+            {
+                if (op.CanProcess(node))
+                {
+                    nodesToProcess.Add(node);
                 }
-                if (!op.Process(targetNode, _options)) {
-                    Console.WriteLine(targetNode.NodePath + ": ERROR (apply)");
+                else
+                {
+                    Console.WriteLine(node.NodePath + ": ERROR (invalid command)");
                     failCount++;
                 }
+            }
 
-                targetNode.Root.Save();
+            // Iterate over all the processable nodes and process them.
+            // Doing this separately from the CanProcess loop allows Process to make significant changes to the NBT
+            // tree like node deletion.
 
-                Console.WriteLine(targetNode.NodePath + ": OK");
-                successCount++;
+            foreach (var targetNode in nodesToProcess) {
+                // Since Process may render targetNode inoperable, save targetNode.Root beforehand.
+                var root = targetNode.Root;
+
+                if (op.Process(targetNode, _options))
+                {
+                    // Now that processing has succeeded, save the changes.
+                    root.Save();
+                    Console.WriteLine(targetNode.NodePath + ": OK");
+                    successCount++;
+                }
+                else
+                {
+                    // Since processing failed, discard any changes that may have been made. This prevents other
+                    // iterations of this loop from saving them.
+                    targetNode.RefreshNode();
+                    Console.WriteLine(targetNode.NodePath + ": ERROR (apply)");
+                    failCount++;
+                }
             }
 
             Console.WriteLine("Operation complete.  Nodes succeeded: {0}  Nodes failed: {1}", successCount, failCount);

NBTUtil/NBTUtil.csproj

@@ -45,6 +45,7 @@
     <Compile Include="ConsoleRunner.cs" />
     <Compile Include="NDesk\Options.cs" />
     <Compile Include="Ops\ConsoleOperation.cs" />
+    <Compile Include="Ops\DeleteOperation.cs" />
     <Compile Include="Ops\EditOperation.cs" />
     <Compile Include="Ops\JsonOperation.cs" />
     <Compile Include="Ops\PrintOperation.cs" />

NBTUtil/Ops/DeleteOperation.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using NBTExplorer.Model;
+
+namespace NBTUtil.Ops
+{
+    class DeleteOperation : ConsoleOperation
+    {
+        public override bool OptionsValid (ConsoleOptions options)
+        {
+            return true;
+        }
+
+        public override bool CanProcess (DataNode dataNode)
+        {
+            return (dataNode != null) && dataNode.CanDeleteNode && (dataNode.Root != dataNode);
+        }
+
+        public override bool Process (DataNode dataNode, ConsoleOptions options)
+        {
+            return dataNode.DeleteNode();
+        }
+    }
+}