Added Setting Attribute to easily add setting fields

And also added two different use cases (one is without acustom node view, one with a custom node view)

Author: TeorikDeli

Assets/Examples/DefaultNodes/Editor/IfNodeView.cs

@@ -12,6 +12,7 @@ public class IfNodeView : BaseNodeView
 {
 	public override void Enable()
 	{
+		hasSettings = true;	// or base.Enable();
 		var node = nodeTarget as IfNode;
 
         // Create your fields using node's variables and add them to the controlsContainer

Assets/Examples/DefaultNodes/Nodes/IfNode.cs

@@ -17,6 +17,7 @@ public class IfNode : ConditionalNode
 	[Output(name = "False")]
 	public ConditionalLink	@false;
 
+	[Setting("Compare Function")]
 	public CompareFunction		compareOperator;
 
 	public override string		name => "If";

Assets/Examples/DefaultNodes/Nodes/MessageNode.cs

@@ -14,10 +14,13 @@ public class MessageNode : BaseNode
 
 	public override string		name => "MessageNode";
 
+	[Setting("Message Type")]
+	public NodeMessageType messageType = NodeMessageType.Error;
+
 	protected override void Process()
 	{
 		if (input != 42)
-			AddMessage(k_InputIsNot42Error, NodeMessageType.Error);
+			AddMessage(k_InputIsNot42Error, messageType);
 		else
 			RemoveMessage(k_InputIsNot42Error);
 	}

Assets/com.alelievr.NodeGraphProcessor/Editor/Resources/GraphProcessorStyles/NodeSettings.uss

@@ -1,6 +1,7 @@
 NodeSettingsView {
-    width: 300px;
     position: absolute;
+    min-width: 110px;
+    max-width: 300px;
     -unity-slice-top: 40;
     -unity-slice-left: 80;
     -unity-slice-right: 25;
@@ -18,3 +19,26 @@ NodeSettingsView > #mainContainer {
     padding-right: 4px;
     padding-bottom: 4px;
 }
+
+NodeSettingsView Label#header {
+    padding-bottom: 4px;
+    -unity-font-style: bold;
+}
+
+NodeSettingsView Label.unity-text-element {
+    min-width: 110px;
+    font-size: 10px;
+    padding-right: 6px;
+}
+
+NodeSettingsView .unity-base-field > .unity-base-field__input {
+    justify-content: flex-end;
+    min-width: 20px;
+}
+
+NodeSettingsView > #mainContainer > #contentContainer {
+    padding-top: 4px;
+    padding-left: 8px;
+    padding-right: 8px;
+    padding-bottom: 4px;
+}

Assets/com.alelievr.NodeGraphProcessor/Editor/Views/BaseNodeView.cs

@@ -39,7 +39,7 @@ public class BaseNodeView : NodeView
 		public event Action< PortView >			onPortConnected;
 		public event Action< PortView >			onPortDisconnected;
 
-		protected virtual bool					hasSettings => false;
+		protected virtual bool					hasSettings { get; set; }
 
         public bool								initializing = false; //Used for applying SetPosition on locked node at init.
 
@@ -172,7 +172,12 @@ void InitializeSettings()
 				settings.Add(CreateSettingsView());
 				settingsContainer.Add(settings);
 				Add(settingsContainer);
+				
+				var fields = nodeTarget.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly);
 
+				foreach(var field in fields)
+					if(field.GetCustomAttribute(typeof(SettingAttribute)) != null) 
+						AddSettingField(field);
 			}
 		}
 
@@ -554,6 +559,13 @@ protected virtual void DrawDefaultInspector(bool fromInspector = false)
 
 			foreach (var field in fields)
 			{
+				//skip if the field is a node setting
+				if(field.GetCustomAttribute(typeof(SettingAttribute)) != null)
+				{
+					hasSettings = true;
+					continue;
+				}
+				
 				//skip if the field is not serializable
 				if(!field.IsPublic && field.GetCustomAttribute(typeof(SerializeField)) == null)
 				{
@@ -734,6 +746,25 @@ void UpdateFieldValues()
 			foreach (var kp in fieldControlsMap)
 				UpdateOtherFieldValue(kp.Key, kp.Key.GetValue(nodeTarget));
 		}
+		
+		protected void AddSettingField(FieldInfo field)
+		{
+			if (field == null)
+				return;
+
+			var label = field.GetCustomAttribute<SettingAttribute>().name;
+
+			var element = FieldFactory.CreateField(field.FieldType, field.GetValue(nodeTarget), (newValue) => {
+				owner.RegisterCompleteObjectUndo("Updated " + newValue);
+				field.SetValue(nodeTarget, newValue);
+			}, label);
+
+			if(element != null)
+			{
+				settingsContainer.Add(element);
+				element.name = field.Name;
+			}
+		}
 
 		internal void OnPortConnected(PortView port)
 		{
@@ -970,7 +1001,7 @@ void UpdatePortsForField(string fieldName)
 			RefreshPorts();
 		}
 
-		protected virtual VisualElement CreateSettingsView() => new Label("Settings");
+		protected virtual VisualElement CreateSettingsView() => new Label("Settings") {name = "header"};
 
 		/// <summary>
 		/// Send an event to the graph telling that the content of this node have changed

Assets/com.alelievr.NodeGraphProcessor/Runtime/Graph/Attributes.cs

@@ -201,4 +201,15 @@ public ShowInInspector(bool showInNode = false)
 	public class ShowAsDrawer : Attribute
 	{
 	}
+	
+	[AttributeUsage(AttributeTargets.Field)]
+	public class SettingAttribute : Attribute
+	{
+		public string name;
+
+		public SettingAttribute(string name = null)
+		{
+			this.name = name;
+		}
+	}
 }