Validation WIP

Application/Feeds/Category.cs

@@ -1,9 +1,10 @@
-using Realms;
-using System;
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
+using JetBrains.Annotations;
+using Realms;
 
 namespace FeedCenter
 {
@@ -11,13 +12,21 @@ namespace FeedCenter
     {
         public const string DefaultName = "< default >";
 
-        private readonly Dictionary<string, List<string>> _errorsByPropertyName = new();
+        private readonly DataErrorDictionary _dataErrorDictionary;
+
+        public Category()
+        {
+            _dataErrorDictionary = new DataErrorDictionary();
+            _dataErrorDictionary.ErrorsChanged += DataErrorDictionaryErrorsChanged;
+        }
+
+        [Ignored]
+        public ICollection<Feed> Feeds { get; set; }
 
         [PrimaryKey]
         public Guid Id { get; set; } = Guid.NewGuid();
 
-        [MapTo("Name")]
-        private string RawName { get; set; } = string.Empty;
+        public bool IsDefault { get; internal set; }
 
         public string Name
         {
@@ -31,60 +40,37 @@ namespace FeedCenter
             }
         }
 
-        [Ignored]
-        public ICollection<Feed> Feeds { get; set; }
+        [MapTo("Name")]
+        private string RawName { get; set; } = string.Empty;
+
+        [UsedImplicitly]
+        public int SortKey => IsDefault ? 0 : 1;
+
+        public bool HasErrors => _dataErrorDictionary.Any();
+
+        public IEnumerable GetErrors(string propertyName)
+        {
+            return _dataErrorDictionary.GetErrors(propertyName);
+        }
+
+        public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
+
+        private void DataErrorDictionaryErrorsChanged(object sender, DataErrorsChangedEventArgs e)
+        {
+            ErrorsChanged?.Invoke(this, new DataErrorsChangedEventArgs(e.PropertyName));
+        }
 
         public static Category CreateDefault()
         {
             return new Category { Name = DefaultName, IsDefault = true };
         }
 
-        public bool IsDefault { get; internal set; }
-
-        // ReSharper disable once UnusedMember.Global
-        public int SortKey => IsDefault ? 0 : 1;
-
-        public bool HasErrors => _errorsByPropertyName.Any();
-
-        public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
-
-        public IEnumerable GetErrors(string propertyName)
-        {
-            return _errorsByPropertyName.TryGetValue(propertyName, out var value) ? value : null;
-        }
-
-        private void OnErrorsChanged(string propertyName)
-        {
-            ErrorsChanged?.Invoke(this, new DataErrorsChangedEventArgs(propertyName));
-        }
-
         private void ValidateName()
         {
-            ClearErrors(nameof(Name));
+            _dataErrorDictionary.ClearErrors(nameof(Name));
 
             if (string.IsNullOrWhiteSpace(Name))
-                AddError(nameof(Name), "Name cannot be empty");
-        }
-
-        private void AddError(string propertyName, string error)
-        {
-            if (!_errorsByPropertyName.ContainsKey(propertyName))
-                _errorsByPropertyName[propertyName] = new List<string>();
-
-            if (_errorsByPropertyName[propertyName].Contains(error))
-                return;
-
-            _errorsByPropertyName[propertyName].Add(error);
-            OnErrorsChanged(propertyName);
-        }
-
-        private void ClearErrors(string propertyName)
-        {
-            if (!_errorsByPropertyName.ContainsKey(propertyName))
-                return;
-
-            _errorsByPropertyName.Remove(propertyName);
-            OnErrorsChanged(propertyName);
+                _dataErrorDictionary.AddError(nameof(Name), "Name cannot be empty");
         }
     }
 }