Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System/sys/system/configuration/DictionarySectionHandler.cs

@@ -0,0 +1,104 @@
+//------------------------------------------------------------------------------
+// <copyright file="DictionarySectionHandler.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Configuration {
+    using System.Collections;
+    using System.Collections.Specialized;
+    using System.Xml;
+    using System.Globalization;
+
+    /// <devdoc>
+    /// Simple dictionary config factory
+    /// config is a dictionary mapping key-&gt;value
+    /// 
+    ///     &lt;add key="name" value="text"&gt;  sets key=text 
+    ///     &lt;remove key="name"&gt;            removes the definition of key
+    ///     &lt;clear&gt;                        removes all definitions
+    /// 
+    /// </devdoc>
+    public class DictionarySectionHandler : IConfigurationSectionHandler {
+
+        /// <devdoc>
+        /// Given a partially composed config object (possibly null)
+        /// and some input from the config system, return a
+        /// further partially composed config object
+        /// </devdoc>
+        public virtual object Create(Object parent, Object context, XmlNode section) {
+            Hashtable res;
+
+            // start res off as a shallow clone of the parent
+
+            if (parent == null)
+                res = new Hashtable(StringComparer.OrdinalIgnoreCase);
+            else
+                res = (Hashtable)((Hashtable)parent).Clone();
+
+            // process XML
+
+            HandlerBase.CheckForUnrecognizedAttributes(section);
+
+            foreach (XmlNode child in section.ChildNodes) {
+
+                // skip whitespace and comments, throws if non-element
+                if (HandlerBase.IsIgnorableAlsoCheckForNonElement(child))
+                    continue;
+
+                // handle <add>, <remove>, <clear> tags
+                if (child.Name == "add") {
+                    HandlerBase.CheckForChildNodes(child);
+                    String key = HandlerBase.RemoveRequiredAttribute(child, KeyAttributeName);
+                    String value;
+                    if (ValueRequired)
+                        value = HandlerBase.RemoveRequiredAttribute(child, ValueAttributeName);
+                    else
+                        value = HandlerBase.RemoveAttribute(child, ValueAttributeName);
+                    HandlerBase.CheckForUnrecognizedAttributes(child);
+
+                    if (value == null)
+                        value = "";
+
+                    res[key] = value;
+                }
+                else if (child.Name == "remove") {
+                    HandlerBase.CheckForChildNodes(child);
+                    String key = HandlerBase.RemoveRequiredAttribute(child, KeyAttributeName);
+                    HandlerBase.CheckForUnrecognizedAttributes(child);
+
+                    res.Remove(key);
+                }
+                else if (child.Name.Equals("clear")) {
+                    HandlerBase.CheckForChildNodes(child);
+                    HandlerBase.CheckForUnrecognizedAttributes(child);
+                    res.Clear();
+                }
+                else {
+                    HandlerBase.ThrowUnrecognizedElement(child);
+                }
+            }
+
+            return res;
+        }
+
+        /// <devdoc>
+        ///    Make the name of the key attribute configurable by derived classes.
+        /// </devdoc>
+        protected virtual string KeyAttributeName {
+            get { return "key";}
+        }
+
+        /// <devdoc>
+        ///    Make the name of the value attribute configurable by derived classes.
+        /// </devdoc>
+        protected virtual string ValueAttributeName {
+            get { return "value";}
+        }
+
+        // 
+        internal virtual bool ValueRequired {
+            get { return false; }
+        }
+    }
+}