1 files changed, 44 insertions, 0 deletions
diff --git a/Juick/ViewModels/Validation/DataViewModelBase.cs b/Juick/ViewModels/Validation/DataViewModelBase.cs
new file mode 100644
index 0000000..dcbf34b
--- /dev/null
+++ b/Juick/ViewModels/Validation/DataViewModelBase.cs
@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+
+namespace Juick.ViewModels.Validation
+{
+    public class DataViewModelBase : ViewModelBase, IDataErrorInfo
+    {
+
+        private readonly Dictionary<String, List<String>> _errors =
+           new Dictionary<string, List<string>>();
+
+        // Adds the specified error to the errors collection if it is not already 
+        // present, inserting it in the first position if isWarning is false. 
+        public void AddError(string propertyName, string error, bool isWarning)
+        {
+            if (!_errors.ContainsKey(propertyName))
+                _errors[propertyName] = new List<string>();
+
+            if (_errors[propertyName].Contains(error)) return;
+            if (isWarning) _errors[propertyName].Add(error);
+            else _errors[propertyName].Insert(0, error);
+        }
+
+        // Removes the specified error from the errors collection if it is present. 
+        public void RemoveError(string propertyName, string error)
+        {
+            if (!_errors.ContainsKey(propertyName) || !_errors[propertyName].Contains(error)) return;
+            _errors[propertyName].Remove(error);
+            if (_errors[propertyName].Count == 0) _errors.Remove(propertyName);
+        }
+
+        public string Error { get { throw new NotImplementedException(); } }
+
+        public string this[string columnName]
+        {
+            get
+            {
+                return (!_errors.ContainsKey(columnName) ? null :
+                    String.Join(Environment.NewLine, _errors[columnName]));
+            }
+        }
+    }
+}