Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/Configuration/ProvidersHelper.cs

@@ -0,0 +1,57 @@
+//------------------------------------------------------------------------------
+// <copyright file="ProvidersHelper.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.Configuration
+{
+    using System.Configuration;
+    using System.Configuration.Provider;
+    using System.Web.Compilation;
+    using System.Collections.Specialized;
+    using System;
+    using System.Security;
+    using System.Security.Permissions;
+
+    public static class ProvidersHelper {
+        ///////////////////////////////////////////////////////////////////////////////
+        ///////////////////////////////////////////////////////////////////////////////
+        [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Low)]
+        public static ProviderBase InstantiateProvider(ProviderSettings providerSettings, Type providerType)
+        {
+            ProviderBase provider = null;
+            try {
+                string pnType = (providerSettings.Type == null) ? null : providerSettings.Type.Trim();
+                if (string.IsNullOrEmpty(pnType))
+                    throw new ArgumentException(SR.GetString(SR.Provider_no_type_name));
+                Type t = ConfigUtil.GetType(pnType, "type", providerSettings, true, true);
+
+                if (!providerType.IsAssignableFrom(t))
+                    throw new ArgumentException(SR.GetString(SR.Provider_must_implement_type, providerType.ToString()));
+                provider = (ProviderBase)HttpRuntime.CreatePublicInstance(t);
+
+                // Because providers modify the parameters collection (i.e. delete stuff), pass in a clone of the collection
+                NameValueCollection pars = providerSettings.Parameters;
+                NameValueCollection cloneParams = new NameValueCollection(pars.Count, StringComparer.Ordinal);
+                foreach (string key in pars)
+                    cloneParams[key] = pars[key];
+                provider.Initialize(providerSettings.Name, cloneParams);
+            } catch (Exception e) {
+                if (e is ConfigurationException)
+                    throw;
+                throw new ConfigurationErrorsException(e.Message, e, providerSettings.ElementInformation.Properties["type"].Source, providerSettings.ElementInformation.Properties["type"].LineNumber);
+            }
+
+            return provider;
+        }
+
+        [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Low)]
+        public static void InstantiateProviders(ProviderSettingsCollection configProviders, ProviderCollection providers, Type providerType)
+        {
+            foreach (ProviderSettings ps in configProviders) {
+                providers.Add(InstantiateProvider(ps, providerType));
+            }
+        }
+    }
+}