Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Configuration/System/Configuration/RegexStringValidator.cs

@@ -0,0 +1,53 @@
+//------------------------------------------------------------------------------
+// <copyright file="RegexStringValidator.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+using System;
+using System.Collections;
+using System.IO;
+using System.Reflection;
+using System.Security.Permissions;
+using System.Xml;
+using System.Collections.Specialized;
+using System.Globalization;
+using System.ComponentModel;
+using System.Security;
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace System.Configuration {
+
+    public class RegexStringValidator : ConfigurationValidatorBase {
+        private string _expression;
+        private Regex _regex;
+
+        public RegexStringValidator(string regex) {
+            if (string.IsNullOrEmpty(regex)) {
+                throw ExceptionUtil.ParameterNullOrEmpty("regex");
+            }
+
+            _expression = regex;
+            _regex = new Regex(regex, RegexOptions.Compiled);
+        }
+        
+        public override bool CanValidate(Type type) {
+            return (type == typeof(string));
+        }
+
+        public override void Validate(object value) {
+            ValidatorUtils.HelperParamValidation(value, typeof(string));
+
+            if (value == null) {
+                return;
+            }
+
+            Match match = _regex.Match((string)value);
+
+            if (!match.Success) {
+                throw new ArgumentException(SR.GetString(SR.Regex_validator_error, _expression));
+            }
+        }
+    }
+}