Path validation

* invalid path message
* its validation attribute

src/Yavsc.Abstract/Attributes/Validation/ValidRemoteUserDirAttribute.cs

@@ -0,0 +1,32 @@
+
+using System;
+using System.ComponentModel.DataAnnotations;
+using Yavsc.Helpers;
+
+namespace Yavsc.Attributes.Validation
+{ 
+    /// <summary>
+    /// Valid Remote User Dir Attribute
+    /// </summary>
+    public class ValidRemoteUserFilePathAttribute : ValidationAttribute
+    {
+        public ValidRemoteUserFilePathAttribute()
+        {
+            UseDefaultErrorMessage();
+        }
+        void UseDefaultErrorMessage()
+        {
+            if (ErrorMessageResourceType==null)  {
+                ErrorMessageResourceType = typeof(Yavsc.Attributes.Validation.Resources);
+                ErrorMessageResourceName = "InvalidPath"; 
+            }
+        }
+
+        public override bool IsValid(object value)
+        {
+            if (value == null) return true;
+            var str = (string) value;
+            return str.IsValidYavscPath();
+        }
+    }
+}