Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/UI/XPathBinder.cs

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+//------------------------------------------------------------------------------
+// <copyright file="XPathBinder.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI {
+
+    using System;
+    using System.Globalization;
+    using System.Collections;
+    using System.ComponentModel;
+    using System.ComponentModel.Design;
+    using System.Data;
+    using System.Xml;
+    using System.Xml.XPath;
+
+
+    /// <devdoc>
+    /// </devdoc>
+    public sealed class XPathBinder {
+
+        /// <internalonly/>
+        private XPathBinder() {
+        }
+
+
+        /// <devdoc>
+        /// </devdoc>
+        public static object Eval(object container, string xPath) {
+            IXmlNamespaceResolver resolver = null;
+            return Eval(container, xPath, resolver);
+        }
+
+        public static object Eval(object container, string xPath, IXmlNamespaceResolver resolver) {
+            if (container == null) {
+                throw new ArgumentNullException("container");
+            }
+            if (String.IsNullOrEmpty(xPath)) {
+                throw new ArgumentNullException("xPath");
+            }
+
+            IXPathNavigable node = container as IXPathNavigable;
+            if (node == null) {
+                throw new ArgumentException(SR.GetString(SR.XPathBinder_MustBeIXPathNavigable, container.GetType().FullName));
+            }
+            XPathNavigator navigator = node.CreateNavigator();
+
+            object retValue = navigator.Evaluate(xPath, resolver);
+
+            // If we get back an XPathNodeIterator instead of a simple object, advance
+            // the iterator to the first node and return the value.
+            XPathNodeIterator iterator = retValue as XPathNodeIterator;
+            if (iterator != null) {
+                if (iterator.MoveNext()) {
+                    retValue = iterator.Current.Value;
+                }
+                else {
+                    retValue = null;
+                }
+            }
+
+            return retValue;
+        }
+
+
+        /// <devdoc>
+        /// </devdoc>
+        public static string Eval(object container, string xPath, string format) {
+            return Eval(container, xPath, format, null);
+        }
+
+        public static string Eval(object container, string xPath, string format, IXmlNamespaceResolver resolver) {
+            object value = XPathBinder.Eval(container, xPath, resolver);
+
+            if (value == null) {
+                return String.Empty;
+            }
+            else {
+                if (String.IsNullOrEmpty(format)) {
+                    return value.ToString();
+                }
+                else {
+                    return String.Format(format, value);
+                }
+            }
+        }
+
+
+        /// <devdoc>
+        /// Evaluates an XPath query with respect to a context IXPathNavigable object that returns a NodeSet.
+        /// </devdoc>
+        public static IEnumerable Select(object container, string xPath) {
+            return Select(container, xPath, null);
+        }
+
+        public static IEnumerable Select(object container, string xPath, IXmlNamespaceResolver resolver) {
+            if (container == null) {
+                throw new ArgumentNullException("container");
+            }
+            if (String.IsNullOrEmpty(xPath)) {
+                throw new ArgumentNullException("xPath");
+            }
+
+            ArrayList results = new ArrayList();
+
+            IXPathNavigable node = container as IXPathNavigable;
+            if (node == null) {
+                throw new ArgumentException(SR.GetString(SR.XPathBinder_MustBeIXPathNavigable, container.GetType().FullName));
+            }
+            XPathNavigator navigator = node.CreateNavigator();
+            XPathNodeIterator iterator = navigator.Select(xPath, resolver);
+
+            while (iterator.MoveNext()) {
+                IHasXmlNode hasXmlNode = iterator.Current as IHasXmlNode;
+                if (hasXmlNode == null) {
+                    throw new InvalidOperationException(SR.GetString(SR.XPathBinder_MustHaveXmlNodes));
+                }
+                results.Add(hasXmlNode.GetNode());
+            }
+
+            return results;
+        }
+    }
+}
+