Add field manipulator class

SabreTools.Filter/FieldManipulator.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Linq;
+using SabreTools.Models.Internal;
+
+namespace SabreTools.Filter
+{
+    public static class FieldManipulator
+    {
+        /// <summary>
+        /// Set a field in a given DictionaryBase
+        /// </summary>
+        public static bool SetField(DictionaryBase? dictionaryBase, string? fieldName, object value)
+        {
+            if (dictionaryBase == null || fieldName == null)
+                return false;
+
+            var constants = TypeHelper.GetConstants(typeof(DictionaryBase));
+            if (constants == null || !constants.Any(c => string.Equals(c, fieldName, StringComparison.InvariantCultureIgnoreCase)))
+                return false;
+
+            dictionaryBase[fieldName] = value;
+            return true;
+        }
+
+        /// <summary>
+        /// Remove a field from a given DictionaryBase
+        /// </summary>
+        public static bool RemoveField(DictionaryBase? dictionaryBase, string? fieldName)
+        {
+            if (dictionaryBase == null || fieldName == null)
+                return false;
+
+            if (!dictionaryBase.ContainsKey(fieldName))
+                return false;
+
+            dictionaryBase.Remove(fieldName);
+            return true;
+        }
+    }
+}