My data resets when I apply the change in a custom inspector

Question

I'm doing a Visual Scripting For unity, but I when I set a value to a value using my custom editor it just make it default, here the code of the I know for the tag UnityEditor.CustomEditor, But I have it on my script so basicly the custom editor works but it just the variables that just reset

custom editor:

public class CustomEditor : Editor
{
    public SerializedProperty
         state_Prop,
         pos_Prop,
         text_Prop,
         number_Prop;
    private void OnEnable()
    {
        state_Prop = serializedObject.FindProperty("var_type");
        pos_Prop = serializedObject.FindProperty("pos");
        text_Prop = serializedObject.FindProperty("text");
        number_Prop = serializedObject.FindProperty("number");
    }

    public override void OnInspectorGUI()
    {
        serializedObject.Update();

        SetVariables t = target as SetVariables;

        EditorGUILayout.PropertyField(state_Prop);

        SetVariables.type_of_variable st = (SetVariables.type_of_variable)state_Prop.enumValueIndex;
        
        EditorGUILayout.ObjectField(serializedObject.FindProperty("variable"));

        switch (st)
        {
            case SetVariables.type_of_variable.POSITION:
                
                EditorGUILayout.Vector3Field("Position", t.pos);
                break;
            case SetVariables.type_of_variable.TEXT:
                EditorGUILayout.TextField("Text", t.text);
                break;
            case SetVariables.type_of_variable.NUMBER:
                EditorGUILayout.FloatField("Number", t.number);
                break;
        }
        

        serializedObject.ApplyModifiedProperties();
    }
}

Answer 1

First of all you would need to assign the returned values to something

t.pos = EditorGUILayout.Vector3Field("Position", t.pos);

and

t.text = EditorGUILayout.TextField("Text", t.text);

and

t.number = EditorGUILayout.FloatField("Number", t.number);

and also actually

serializedObject.FindProperty("variable").objectReferenceValue = EditorGUILayout.ObjectField(serializedObject.FindProperty("variable"));

BUT DO NOT DO THIS!

---

In general do not assign things directly to the target (unless you know exactly what you are doing)!

This lacks dirty state handling and therefore there will be no Undo/Redo and also no persistent saving! It might appear to be assigned in the Inspector but you might be losing those changes with the next reload (e.g. scene switch, re-import or simply closing and re-opening the project)!

You either have to get the values, assign them and explicitly mark your object dirty e.g. using Undo.RecordObject like

switch (st)
{
    case SetVariables.type_of_variable.POSITION:
        using (var check = new EditorGUI.ChangeCheckScope())
        {
            var newPos = EditorGUILayout.Vector3Field("Position", t.pos);

            if (check.changed)
            {
                Undo.RecordObject(target, "Changed position");
                t.pos = newPos;
            }
        }
        break;

    case SetVariables.type_of_variable.TEXT:
        using (var check = new EditorGUI.ChangeCheckScope())
        {
            var newText = EditorGUILayout.TextField("Text", t.text);

            if (check.changed)
            {
                Undo.RecordObject(target, "Changed text");
                t.text = newText;
            }
        }      
        break;

    case SetVariables.type_of_variable.NUMBER:
        using (var check = new EditorGUI.ChangeCheckScope())
        {
            var newNumber = EditorGUILayout.FloatField("Number", t.number);

            if (check.changed)
            {
                Undo.RecordObject(target, "Changed number");
                t.number = newNumber;
            }
        }     
        break;
}

Or - and I would prefer that - why not again go through proper SerializedProperties you already have anyway and rather let Unity decide how to draw them like

switch (st)
{
    case SetVariables.type_of_variable.POSITION:
        // This would simply use the name according to your field name ("Pos" in your case)
        //EditorGUILayout.PropretyField(pos_Prop);
        // This rather overwrites with a custom name
        EditorGUILayout.PropretyField(pos_Prop, new GUIContent("Position"));
        break;

    case SetVariables.type_of_variable.TEXT:
        EditorGUILayout.PropretyField(text_Prop);
        break;

    case SetVariables.type_of_variable.NUMBER:
        EditorGUILayout.PropertyField(number_Prop);
        break;
}

and also

// Just as an example without the label
EditorGUILayout.PropertyField(serializedObject.FindProperty("variable"), GUIContent.None);

The EditorGUILayout.PropertyField already deals with all the dirty states and Undo/Redo handling for you as long as you call the

serializedObject.ApplyModifiedProperties();