Add template project

Template/ItemEntry.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections;
+using System.ComponentModel;
+using System.Linq;
+using System.Text.Json.Serialization;
+
+namespace Template;
+
+public class ItemEntry : INotifyDataErrorInfo
+{
+    private readonly DataErrorDictionary _dataErrorDictionary;
+
+    public ItemEntry()
+    {
+        _dataErrorDictionary = new DataErrorDictionary();
+        _dataErrorDictionary.ErrorsChanged += DataErrorDictionaryErrorsChanged;
+    }
+
+    public string Name
+    {
+        get;
+        set
+        {
+            if (!ValidateName(value))
+                return;
+
+            field = value;
+        }
+    }
+
+    [JsonIgnore]
+    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));
+    }
+
+    private bool ValidateName(string newValue)
+    {
+        _dataErrorDictionary.ClearErrors(nameof(Name));
+
+        if (!string.IsNullOrWhiteSpace(newValue))
+            return true;
+
+        _dataErrorDictionary.AddError(nameof(Name), "Name cannot be empty");
+
+        return false;
+    }
+}