Pull request JanKallman#334 Make validation optional. New property In…

…ternalValidationEnabled on ExcelDataValidationCollection

EPPlus/DataValidation/ExcelDataValidationCollection.cs

@@ -107,6 +107,8 @@ internal ExcelDataValidationCollection(ExcelWorksheet worksheet)
             {
                 OnValidationCountChanged();
             }
+
+            InternalValidationEnabled = true;
         }
 
         private void EnsureRootElementExists()
@@ -161,6 +163,8 @@ private void ValidateAddress(string address, IExcelDataValidation validatingVali
         {
             Require.Argument(address).IsNotNullOrEmpty("address");
 
+            if (!InternalValidationEnabled) return;
+
             // ensure that the new address does not collide with an existing validation.
             var newAddress = new ExcelAddress(address);
             if (_validations.Count > 0)
@@ -190,6 +194,8 @@ private void ValidateAddress(string address)
         /// </summary>
         internal void ValidateAll()
         {
+            if (!InternalValidationEnabled) return;
+
             foreach (var validation in _validations)
             {
                 validation.Validate();
@@ -344,6 +350,18 @@ public int Count
             get { return _validations.Count; }
         }
 
+
+        /// <summary>
+        /// Epplus validates that all data validations are consistend and valid
+        /// when they are added and when a workbook is saved. Since this takes some
+        /// resources, it can be disabled for improve performance. 
+        /// </summary>
+        public bool InternalValidationEnabled
+        {
+            get;
+            set;
+        }
+
         /// <summary>
         /// Index operator, returns by 0-based index
         /// </summary>