Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.ServiceModel/System/ServiceModel/Syndication/FeedUtils.cs

@@ -0,0 +1,143 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace System.ServiceModel.Syndication
+{
+    using System.Collections.ObjectModel;
+    using System.Xml;
+    using System.Xml.Serialization;
+    using System.Runtime.Serialization;
+    using System.Globalization;
+
+    static class FeedUtils
+    {
+        public static string AddLineInfo(XmlReader reader, string error)
+        {
+            IXmlLineInfo lineInfo = reader as IXmlLineInfo;
+            if (lineInfo != null && lineInfo.HasLineInfo())
+            {
+                error = String.Format(CultureInfo.InvariantCulture, "{0} {1}", SR.GetString(SR.ErrorInLine, lineInfo.LineNumber, lineInfo.LinePosition), SR.GetString(error));
+            }
+            return error;
+        }
+
+        static internal Collection<SyndicationCategory> CloneCategories(Collection<SyndicationCategory> categories)
+        {
+            if (categories == null)
+            {
+                return null;
+            }
+            Collection<SyndicationCategory> result = new NullNotAllowedCollection<SyndicationCategory>();
+            for (int i = 0; i < categories.Count; ++i)
+            {
+                result.Add(categories[i].Clone());
+            }
+            return result;
+        }
+
+        static internal Collection<SyndicationLink> CloneLinks(Collection<SyndicationLink> links)
+        {
+            if (links == null)
+            {
+                return null;
+            }
+            Collection<SyndicationLink> result = new NullNotAllowedCollection<SyndicationLink>();
+            for (int i = 0; i < links.Count; ++i)
+            {
+                result.Add(links[i].Clone());
+            }
+            return result;
+        }
+
+        static internal Collection<SyndicationPerson> ClonePersons(Collection<SyndicationPerson> persons)
+        {
+            if (persons == null)
+            {
+                return null;
+            }
+            Collection<SyndicationPerson> result = new NullNotAllowedCollection<SyndicationPerson>();
+            for (int i = 0; i < persons.Count; ++i)
+            {
+                result.Add(persons[i].Clone());
+            }
+            return result;
+        }
+
+        static internal TextSyndicationContent CloneTextContent(TextSyndicationContent content)
+        {
+            if (content == null)
+            {
+                return null;
+            }
+            return (TextSyndicationContent)(content.Clone());
+        }
+
+        internal static Uri CombineXmlBase(Uri rootBase, string newBase)
+        {
+            if (string.IsNullOrEmpty(newBase))
+            {
+                return rootBase;
+            }
+            Uri newBaseUri = new Uri(newBase, UriKind.RelativeOrAbsolute);
+            if (rootBase == null || newBaseUri.IsAbsoluteUri)
+            {
+                return newBaseUri;
+            }
+            return new Uri(rootBase, newBase);
+        }
+
+        internal static Uri GetBaseUriToWrite(Uri rootBase, Uri currentBase)
+        {
+            Uri uriToWrite;
+            if (rootBase == currentBase || currentBase == null)
+            {
+                uriToWrite = null;
+            }
+            else if (rootBase == null)
+            {
+                uriToWrite = currentBase;
+            }
+            else
+            {
+                // rootBase != currentBase and both are not null
+                // Write the relative base if possible
+                if (rootBase.IsAbsoluteUri && currentBase.IsAbsoluteUri && rootBase.IsBaseOf(currentBase))
+                {
+                    uriToWrite = rootBase.MakeRelativeUri(currentBase);
+                }
+                else
+                {
+                    uriToWrite = currentBase;
+                }
+            }
+            return uriToWrite;
+        }
+
+        static internal string GetUriString(Uri uri)
+        {
+            if (uri == null)
+            {
+                return null;
+            }
+            if (uri.IsAbsoluteUri)
+            {
+                return uri.AbsoluteUri;
+            }
+            else
+            {
+                return uri.ToString();
+            }
+        }
+
+        static internal bool IsXmlns(string name, string ns)
+        {
+            return name == "xmlns" || ns == "http://www.w3.org/2000/xmlns/";
+        }
+
+        internal static bool IsXmlSchemaType(string name, string ns)
+        {
+            return name == "type" && ns == "http://www.w3.org/2001/XMLSchema-instance";
+        }
+    }
+}