[AssetBundleGraphTool] Custom node sample code to set SpriteTag by Group

SetSpriteTag.cs

using UnityEngine;
using UnityEditor;

using System;
using System.Linq;
using System.IO;
using System.Collections.Generic;
using System.Text.RegularExpressions;

using UnityEngine.AssetBundles.GraphTool;
using Model=UnityEngine.AssetBundles.GraphTool.DataModel.Version2;

/**
	ImportSetting is the class for apply specific setting to already imported files.
*/
[CustomNode("Set Sprite Tag", 100)]
public class SetSpriteTag : Node {

	[SerializeField] private SerializableMultiTargetString m_spriteTagNameTemplate;

	public override string ActiveStyle {
		get {
			return "flow node 2 on";
		}
	}

	public override string InactiveStyle {
		get {
			return "flow node 2";
		}
	}

	public override void Initialize(Model.NodeData data) {

		m_spriteTagNameTemplate = new SerializableMultiTargetString("SpriteTag_*");

		data.AddDefaultInputPoint();
		data.AddDefaultOutputPoint();
	}

	public override Node Clone() {
		var newNode = new SetSpriteTag();
		return newNode;
	}

	public override void OnInspectorGUI(NodeGUI node, AssetReferenceStreamManager streamManager, NodeGUIEditor editor, Action onValueChanged) {

		EditorGUILayout.HelpBox("Set Sprite Tag: Configure sprite tag name on asset's importer.", MessageType.Info);
		editor.UpdateNodeName(node);

		GUILayout.Space(10f);

		//Show target configuration tab
		editor.DrawPlatformSelector(node);
		using (new EditorGUILayout.VerticalScope(GUI.skin.box)) {
			// Draw Platform selector tab. 
			var disabledScope = editor.DrawOverrideTargetToggle(node, m_spriteTagNameTemplate.ContainsValueOf(editor.CurrentEditingGroup), (bool b) => {
				using(new RecordUndoScope("Remove Target Platform Settings", node, true)) {
					if(b) {
						m_spriteTagNameTemplate[editor.CurrentEditingGroup] = m_spriteTagNameTemplate.DefaultValue;
					} else {
						m_spriteTagNameTemplate.Remove(editor.CurrentEditingGroup);
					}
					onValueChanged();
				}
			});

			// Draw tab contents
			using (disabledScope) {
				var val = m_spriteTagNameTemplate[editor.CurrentEditingGroup];

				var newValue = EditorGUILayout.TextField("Tag Config:", val);
				if (newValue != val) {
					using(new RecordUndoScope("Tag Name", node, true)){
						m_spriteTagNameTemplate[editor.CurrentEditingGroup] = newValue;
						onValueChanged();
					}
				}
				EditorGUILayout.HelpBox(
					"You can configure tag name with \"*\" to include group name in your sprite tag.", 
					MessageType.Info);
			}
		}
	}

	/**
	 * Prepare is called whenever graph needs update. 
	 */ 
	public override void Prepare (BuildTarget target, 
		Model.NodeData node, 
		IEnumerable<PerformGraph.AssetGroups> incoming, 
		IEnumerable<Model.ConnectionData> connectionsToOutput, 
		PerformGraph.Output Output) 
	{
		// Pass incoming assets straight to Output
		var destination = (connectionsToOutput == null || !connectionsToOutput.Any())? 
			null : connectionsToOutput.First();

		if(incoming != null) {

			ApplySpriteTag(target, incoming);

			if(Output != null) {
				foreach(var ag in incoming) {
					Output(destination, ag.assetGroups);
				}
			}
		} else {
			if(Output != null) {
				// Overwrite output with empty Dictionary when no there is incoming asset
				Output(destination, new Dictionary<string, List<AssetReference>>());
			}
		}
	}

	private string GetTagName(BuildTarget target, string groupName) {
		return m_spriteTagNameTemplate[target].Replace("*", groupName);
	}

	private void ApplySpriteTag(BuildTarget target, IEnumerable<PerformGraph.AssetGroups> incoming) {

		foreach(var ag in incoming) {
			foreach(var groupKey in ag.assetGroups.Keys) {
				var assets = ag.assetGroups[groupKey];
				foreach(var asset in assets) {

					if(asset.filterType == typeof(UnityEditor.TextureImporter) ) {
						var importer = AssetImporter.GetAtPath(asset.importFrom) as TextureImporter;

						importer.spritePackingTag = GetTagName(target, groupKey);
						importer.SaveAndReimport();
						asset.TouchImportAsset();
					}
				}
			}
		}
	}
}