moving from Yavsc main lib

Yavsc.Server/Attributes/Validation/YaStringLength.cs

@@ -0,0 +1,58 @@
+namespace Yavsc.Attributes.Validation
+{
+    public class YaStringLength: YaValidationAttribute
+    {
+        public long MinLen { get; set; } = -1;
+        private long maxLen;
+        public YaStringLength(long maxLen) : base(
+            ()=>string.Format(
+                ResourcesHelpers.GlobalLocalizer["BadStringLength"],
+                maxLen))
+        {
+            this.maxLen = maxLen;
+        }
+
+        private long excedent;
+        private long manquant;
+
+        public override bool IsValid(object value) {
+            if (value == null) {
+                return false;
+            }
+            string stringValue = value as string;
+            if (stringValue==null) return false;
+            if (MinLen>=0) 
+                {
+                    if (stringValue.Length<MinLen)
+                    {
+                        manquant = MinLen-stringValue.Length;
+                    }
+                    return false;
+                }
+            if (maxLen>=0)
+                {
+                    if (stringValue.Length>maxLen) {
+                        excedent = stringValue.Length-maxLen;
+                        return false;
+                    }
+                }
+            return true;
+        }
+        public override string FormatErrorMessage(string name)
+        {
+            if (MinLen<0) {
+                // DetailledMaxStringLength
+                return string.Format(
+                ResourcesHelpers.GlobalLocalizer["DetailledMaxStringLength"],
+                maxLen,
+                excedent);
+            } else 
+                return string.Format(
+                ResourcesHelpers.GlobalLocalizer["DetailledMinMaxStringLength"],
+                MinLen,
+                maxLen,
+                manquant,
+                excedent);
+        }
+    }
+}