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//------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
//------------------------------------------------------------
#pragma warning disable 1634, 1691
namespace System.ServiceModel.Syndication
{
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Runtime;
using System.ServiceModel.Diagnostics;
using System.Text;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
using DiagnosticUtility = System.ServiceModel.DiagnosticUtility;
using System.Runtime.CompilerServices;
[TypeForwardedFrom("System.ServiceModel.Web, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35")]
[XmlRoot(ElementName = Rss20Constants.RssTag, Namespace = Rss20Constants.Rss20Namespace)]
public class Rss20FeedFormatter : SyndicationFeedFormatter, IXmlSerializable
{
static readonly XmlQualifiedName Rss20Domain = new XmlQualifiedName(Rss20Constants.DomainTag, string.Empty);
static readonly XmlQualifiedName Rss20Length = new XmlQualifiedName(Rss20Constants.LengthTag, string.Empty);
static readonly XmlQualifiedName Rss20Type = new XmlQualifiedName(Rss20Constants.TypeTag, string.Empty);
static readonly XmlQualifiedName Rss20Url = new XmlQualifiedName(Rss20Constants.UrlTag, string.Empty);
const string Rfc822OutputLocalDateTimeFormat = "ddd, dd MMM yyyy HH:mm:ss zzz";
const string Rfc822OutputUtcDateTimeFormat = "ddd, dd MMM yyyy HH:mm:ss Z";
Atom10FeedFormatter atomSerializer;
Type feedType;
int maxExtensionSize;
bool preserveAttributeExtensions;
bool preserveElementExtensions;
bool serializeExtensionsAsAtom;
public Rss20FeedFormatter()
: this(typeof(SyndicationFeed))
{
}
public Rss20FeedFormatter(Type feedTypeToCreate)
: base()
{
if (feedTypeToCreate == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("feedTypeToCreate");
}
if (!typeof(SyndicationFeed).IsAssignableFrom(feedTypeToCreate))
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgument("feedTypeToCreate",
SR.GetString(SR.InvalidObjectTypePassed, "feedTypeToCreate", "SyndicationFeed"));
}
this.serializeExtensionsAsAtom = true;
this.maxExtensionSize = int.MaxValue;
this.preserveElementExtensions = true;
this.preserveAttributeExtensions = true;
this.atomSerializer = new Atom10FeedFormatter(feedTypeToCreate);
this.feedType = feedTypeToCreate;
}
public Rss20FeedFormatter(SyndicationFeed feedToWrite)
: this(feedToWrite, true)
{
}
public Rss20FeedFormatter(SyndicationFeed feedToWrite, bool serializeExtensionsAsAtom)
: base(feedToWrite)
{
// No need to check that the parameter passed is valid - it is checked by the c'tor of the base class
this.serializeExtensionsAsAtom = serializeExtensionsAsAtom;
this.maxExtensionSize = int.MaxValue;
this.preserveElementExtensions = true;
this.preserveAttributeExtensions = true;
this.atomSerializer = new Atom10FeedFormatter(this.Feed);
this.feedType = feedToWrite.GetType();
}
public bool PreserveAttributeExtensions
{
get { return this.preserveAttributeExtensions; }
set { this.preserveAttributeExtensions = value; }
}
public bool PreserveElementExtensions
{
get { return this.preserveElementExtensions; }
set { this.preserveElementExtensions = value; }
}
public bool SerializeExtensionsAsAtom
{
get { return this.serializeExtensionsAsAtom; }
set { this.serializeExtensionsAsAtom = value; }
}
public override string Version
{
get { return SyndicationVersions.Rss20; }
}
protected Type FeedType
{
get
{
return this.feedType;
}
}
public override bool CanRead(XmlReader reader)
{
if (reader == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("reader");
}
return reader.IsStartElement(Rss20Constants.RssTag, Rss20Constants.Rss20Namespace);
}
[SuppressMessage("Microsoft.Design", "CA1033:InterfaceMethodsShouldBeCallableByChildTypes", Justification = "The IXmlSerializable implementation is only for exposing under WCF DataContractSerializer. The funcionality is exposed to derived class through the ReadFrom\\WriteTo methods")]
XmlSchema IXmlSerializable.GetSchema()
{
return null;
}
[SuppressMessage("Microsoft.Design", "CA1033:InterfaceMethodsShouldBeCallableByChildTypes", Justification = "The IXmlSerializable implementation is only for exposing under WCF DataContractSerializer. The funcionality is exposed to derived class through the ReadFrom\\WriteTo methods")]
void IXmlSerializable.ReadXml(XmlReader reader)
{
if (reader == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("reader");
}
TraceFeedReadBegin();
ReadFeed(reader);
TraceFeedReadEnd();
}
[SuppressMessage("Microsoft.Design", "CA1033:InterfaceMethodsShouldBeCallableByChildTypes", Justification = "The IXmlSerializable implementation is only for exposing under WCF DataContractSerializer. The funcionality is exposed to derived class through the ReadFrom\\WriteTo methods")]
void IXmlSerializable.WriteXml(XmlWriter writer)
{
if (writer == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("writer");
}
TraceFeedWriteBegin();
WriteFeed(writer);
TraceFeedWriteEnd();
}
public override void ReadFrom(XmlReader reader)
{
TraceFeedReadBegin();
if (!CanRead(reader))
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new XmlException(SR.GetString(SR.UnknownFeedXml, reader.LocalName, reader.NamespaceURI)));
}
ReadFeed(reader);
TraceFeedReadEnd();
}
public override void WriteTo(XmlWriter writer)
{
if (writer == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("writer");
}
TraceFeedWriteBegin();
writer.WriteStartElement(Rss20Constants.RssTag, Rss20Constants.Rss20Namespace);
WriteFeed(writer);
writer.WriteEndElement();
TraceFeedWriteEnd();
}
protected internal override void SetFeed(SyndicationFeed feed)
{
base.SetFeed(feed);
this.atomSerializer.SetFeed(this.Feed);
}
internal static void TraceExtensionsIgnoredOnWrite(string message)
{
if (DiagnosticUtility.ShouldTraceInformation)
{
TraceUtility.TraceEvent(TraceEventType.Information, TraceCode.SyndicationProtocolElementIgnoredOnWrite, SR.GetString(message));
}
}
internal void ReadItemFrom(XmlReader reader, SyndicationItem result)
{
ReadItemFrom(reader, result, null);
}
internal void WriteItemContents(XmlWriter writer, SyndicationItem item)
{
WriteItemContents(writer, item, null);
}
protected override SyndicationFeed CreateFeedInstance()
{
return SyndicationFeedFormatter.CreateFeedInstance(this.feedType);
}
protected virtual SyndicationItem ReadItem(XmlReader reader, SyndicationFeed feed)
{
if (feed == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("feed");
}
if (reader == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("reader");
}
SyndicationItem item = CreateItem(feed);
TraceItemReadBegin();
ReadItemFrom(reader, item, feed.BaseUri);
TraceItemReadEnd();
return item;
}
[SuppressMessage("Microsoft.Design", "CA1021:AvoidOutParameters", MessageId = "2#", Justification = "The out parameter is needed to enable implementations that read in items from the stream on demand")]
protected virtual IEnumerable<SyndicationItem> ReadItems(XmlReader reader, SyndicationFeed feed, out bool areAllItemsRead)
{
if (feed == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("feed");
}
if (reader == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("reader");
}
NullNotAllowedCollection<SyndicationItem> items = new NullNotAllowedCollection<SyndicationItem>();
while (reader.IsStartElement(Rss20Constants.ItemTag, Rss20Constants.Rss20Namespace))
{
items.Add(ReadItem(reader, feed));
}
areAllItemsRead = true;
return items;
}
protected virtual void WriteItem(XmlWriter writer, SyndicationItem item, Uri feedBaseUri)
{
TraceItemWriteBegin();
writer.WriteStartElement(Rss20Constants.ItemTag, Rss20Constants.Rss20Namespace);
WriteItemContents(writer, item, feedBaseUri);
writer.WriteEndElement();
TraceItemWriteEnd();
}
protected virtual void WriteItems(XmlWriter writer, IEnumerable<SyndicationItem> items, Uri feedBaseUri)
{
if (items == null)
{
return;
}
foreach (SyndicationItem item in items)
{
this.WriteItem(writer, item, feedBaseUri);
}
}
static DateTimeOffset DateFromString(string dateTimeString, XmlReader reader)
{
StringBuilder dateTimeStringBuilder = new StringBuilder(dateTimeString.Trim());
if (dateTimeStringBuilder.Length < 18)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(
new XmlException(FeedUtils.AddLineInfo(reader,
SR.ErrorParsingDateTime)));
}
if (dateTimeStringBuilder[3] == ',')
{
// There is a leading (e.g.) "Tue, ", strip it off
dateTimeStringBuilder.Remove(0, 4);
// There's supposed to be a space here but some implementations dont have one
RemoveExtraWhiteSpaceAtStart(dateTimeStringBuilder);
}
ReplaceMultipleWhiteSpaceWithSingleWhiteSpace(dateTimeStringBuilder);
if (char.IsDigit(dateTimeStringBuilder[1]))
{
// two-digit day, we are good
}
else
{
dateTimeStringBuilder.Insert(0, '0');
}
if (dateTimeStringBuilder.Length < 19)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(
new XmlException(FeedUtils.AddLineInfo(reader,
SR.ErrorParsingDateTime)));
}
bool thereAreSeconds = (dateTimeStringBuilder[17] == ':');
int timeZoneStartIndex;
if (thereAreSeconds)
{
timeZoneStartIndex = 21;
}
else
{
timeZoneStartIndex = 18;
}
string timeZoneSuffix = dateTimeStringBuilder.ToString().Substring(timeZoneStartIndex);
dateTimeStringBuilder.Remove(timeZoneStartIndex, dateTimeStringBuilder.Length - timeZoneStartIndex);
bool isUtc;
dateTimeStringBuilder.Append(NormalizeTimeZone(timeZoneSuffix, out isUtc));
string wellFormattedString = dateTimeStringBuilder.ToString();
DateTimeOffset theTime;
string parseFormat;
if (thereAreSeconds)
{
parseFormat = "dd MMM yyyy HH:mm:ss zzz";
}
else
{
parseFormat = "dd MMM yyyy HH:mm zzz";
}
if (DateTimeOffset.TryParseExact(wellFormattedString, parseFormat,
CultureInfo.InvariantCulture.DateTimeFormat,
(isUtc ? DateTimeStyles.AdjustToUniversal : DateTimeStyles.None), out theTime))
{
return theTime;
}
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(
new XmlException(FeedUtils.AddLineInfo(reader,
SR.ErrorParsingDateTime)));
}
static string NormalizeTimeZone(string rfc822TimeZone, out bool isUtc)
{
isUtc = false;
// return a string in "-08:00" format
if (rfc822TimeZone[0] == '+' || rfc822TimeZone[0] == '-')
{
// the time zone is supposed to be 4 digits but some feeds omit the initial 0
StringBuilder result = new StringBuilder(rfc822TimeZone);
if (result.Length == 4)
{
// the timezone is +/-HMM. Convert to +/-HHMM
result.Insert(1, '0');
}
result.Insert(3, ':');
return result.ToString();
}
switch (rfc822TimeZone)
{
case "UT":
case "Z":
isUtc = true;
return "-00:00";
case "GMT":
return "-00:00";
case "A":
return "-01:00";
case "B":
return "-02:00";
case "C":
return "-03:00";
case "D":
case "EDT":
return "-04:00";
case "E":
case "EST":
case "CDT":
return "-05:00";
case "F":
case "CST":
case "MDT":
return "-06:00";
case "G":
case "MST":
case "PDT":
return "-07:00";
case "H":
case "PST":
return "-08:00";
case "I":
return "-09:00";
case "K":
return "-10:00";
case "L":
return "-11:00";
case "M":
return "-12:00";
case "N":
return "+01:00";
case "O":
return "+02:00";
case "P":
return "+03:00";
case "Q":
return "+04:00";
case "R":
return "+05:00";
case "S":
return "+06:00";
case "T":
return "+07:00";
case "U":
return "+08:00";
case "V":
return "+09:00";
case "W":
return "+10:00";
case "X":
return "+11:00";
case "Y":
return "+12:00";
default:
return "";
}
}
static void RemoveExtraWhiteSpaceAtStart(StringBuilder stringBuilder)
{
int i = 0;
while (i < stringBuilder.Length)
{
if (!char.IsWhiteSpace(stringBuilder[i]))
{
break;
}
++i;
}
if (i > 0)
{
stringBuilder.Remove(0, i);
}
}
static void ReplaceMultipleWhiteSpaceWithSingleWhiteSpace(StringBuilder builder)
{
int index = 0;
int whiteSpaceStart = -1;
while (index < builder.Length)
{
if (char.IsWhiteSpace(builder[index]))
{
if (whiteSpaceStart < 0)
{
whiteSpaceStart = index;
// normalize all white spaces to be ' ' so that the date time parsing works
builder[index] = ' ';
}
}
else if (whiteSpaceStart >= 0)
{
if (index > whiteSpaceStart + 1)
{
// there are at least 2 spaces... replace by 1
builder.Remove(whiteSpaceStart, index - whiteSpaceStart - 1);
index = whiteSpaceStart + 1;
}
whiteSpaceStart = -1;
}
++index;
}
// we have already trimmed the start and end so there cannot be a trail of white spaces in the end
Fx.Assert(builder.Length == 0 || builder[builder.Length - 1] != ' ', "The string builder doesnt end in a white space");
}
string AsString(DateTimeOffset dateTime)
{
if (dateTime.Offset == Atom10FeedFormatter.zeroOffset)
{
return dateTime.ToUniversalTime().ToString(Rfc822OutputUtcDateTimeFormat, CultureInfo.InvariantCulture);
}
else
{
StringBuilder sb = new StringBuilder(dateTime.ToString(Rfc822OutputLocalDateTimeFormat, CultureInfo.InvariantCulture));
// the zzz in Rfc822OutputLocalDateTimeFormat makes the timezone e.g. "-08:00" but we require e.g. "-0800" without the ':'
sb.Remove(sb.Length - 3, 1);
return sb.ToString();
}
}
SyndicationLink ReadAlternateLink(XmlReader reader, Uri baseUri)
{
SyndicationLink link = new SyndicationLink();
link.BaseUri = baseUri;
link.RelationshipType = Atom10Constants.AlternateTag;
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
if (reader.LocalName == "base" && reader.NamespaceURI == Atom10FeedFormatter.XmlNs)
{
link.BaseUri = FeedUtils.CombineXmlBase(link.BaseUri, reader.Value);
}
else if (!FeedUtils.IsXmlns(reader.LocalName, reader.NamespaceURI))
{
if (this.PreserveAttributeExtensions)
{
link.AttributeExtensions.Add(new XmlQualifiedName(reader.LocalName, reader.NamespaceURI), reader.Value);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
}
}
}
}
string uri = reader.ReadElementString();
link.Uri = new Uri(uri, UriKind.RelativeOrAbsolute);
return link;
}
SyndicationCategory ReadCategory(XmlReader reader, SyndicationFeed feed)
{
SyndicationCategory result = CreateCategory(feed);
ReadCategory(reader, result);
return result;
}
SyndicationCategory ReadCategory(XmlReader reader, SyndicationItem item)
{
SyndicationCategory result = CreateCategory(item);
ReadCategory(reader, result);
return result;
}
void ReadCategory(XmlReader reader, SyndicationCategory category)
{
bool isEmpty = reader.IsEmptyElement;
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
string ns = reader.NamespaceURI;
string name = reader.LocalName;
if (FeedUtils.IsXmlns(name, ns))
{
continue;
}
string val = reader.Value;
if (name == Rss20Constants.DomainTag && ns == Rss20Constants.Rss20Namespace)
{
category.Scheme = val;
}
else if (!TryParseAttribute(name, ns, val, category, this.Version))
{
if (this.preserveAttributeExtensions)
{
category.AttributeExtensions.Add(new XmlQualifiedName(name, ns), val);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
}
}
}
}
reader.ReadStartElement(Rss20Constants.CategoryTag, Rss20Constants.Rss20Namespace);
if (!isEmpty)
{
category.Name = reader.ReadString();
reader.ReadEndElement();
}
}
void ReadFeed(XmlReader reader)
{
SetFeed(CreateFeedInstance());
ReadXml(reader, this.Feed);
}
void ReadItemFrom(XmlReader reader, SyndicationItem result, Uri feedBaseUri)
{
try
{
result.BaseUri = feedBaseUri;
reader.MoveToContent();
bool isEmpty = reader.IsEmptyElement;
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
string ns = reader.NamespaceURI;
string name = reader.LocalName;
if (name == "base" && ns == Atom10FeedFormatter.XmlNs)
{
result.BaseUri = FeedUtils.CombineXmlBase(result.BaseUri, reader.Value);
continue;
}
if (FeedUtils.IsXmlns(name, ns) || FeedUtils.IsXmlSchemaType(name, ns))
{
continue;
}
string val = reader.Value;
if (!TryParseAttribute(name, ns, val, result, this.Version))
{
if (this.preserveAttributeExtensions)
{
result.AttributeExtensions.Add(new XmlQualifiedName(name, ns), val);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
}
}
}
}
reader.ReadStartElement();
if (!isEmpty)
{
string fallbackAlternateLink = null;
XmlDictionaryWriter extWriter = null;
bool readAlternateLink = false;
try
{
XmlBuffer buffer = null;
while (reader.IsStartElement())
{
if (reader.IsStartElement(Rss20Constants.TitleTag, Rss20Constants.Rss20Namespace))
{
result.Title = new TextSyndicationContent(reader.ReadElementString());
}
else if (reader.IsStartElement(Rss20Constants.LinkTag, Rss20Constants.Rss20Namespace))
{
result.Links.Add(ReadAlternateLink(reader, result.BaseUri));
readAlternateLink = true;
}
else if (reader.IsStartElement(Rss20Constants.DescriptionTag, Rss20Constants.Rss20Namespace))
{
result.Summary = new TextSyndicationContent(reader.ReadElementString());
}
else if (reader.IsStartElement(Rss20Constants.AuthorTag, Rss20Constants.Rss20Namespace))
{
result.Authors.Add(ReadPerson(reader, result));
}
else if (reader.IsStartElement(Rss20Constants.CategoryTag, Rss20Constants.Rss20Namespace))
{
result.Categories.Add(ReadCategory(reader, result));
}
else if (reader.IsStartElement(Rss20Constants.EnclosureTag, Rss20Constants.Rss20Namespace))
{
result.Links.Add(ReadMediaEnclosure(reader, result.BaseUri));
}
else if (reader.IsStartElement(Rss20Constants.GuidTag, Rss20Constants.Rss20Namespace))
{
bool isPermalink = true;
string permalinkString = reader.GetAttribute(Rss20Constants.IsPermaLinkTag, Rss20Constants.Rss20Namespace);
if ((permalinkString != null) && (permalinkString.ToUpperInvariant() == "FALSE"))
{
isPermalink = false;
}
result.Id = reader.ReadElementString();
if (isPermalink)
{
fallbackAlternateLink = result.Id;
}
}
else if (reader.IsStartElement(Rss20Constants.PubDateTag, Rss20Constants.Rss20Namespace))
{
bool canReadContent = !reader.IsEmptyElement;
reader.ReadStartElement();
if (canReadContent)
{
string str = reader.ReadString();
if (!string.IsNullOrEmpty(str))
{
result.PublishDate = DateFromString(str, reader);
}
reader.ReadEndElement();
}
}
else if (reader.IsStartElement(Rss20Constants.SourceTag, Rss20Constants.Rss20Namespace))
{
SyndicationFeed feed = new SyndicationFeed();
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
string ns = reader.NamespaceURI;
string name = reader.LocalName;
if (FeedUtils.IsXmlns(name, ns))
{
continue;
}
string val = reader.Value;
if (name == Rss20Constants.UrlTag && ns == Rss20Constants.Rss20Namespace)
{
feed.Links.Add(SyndicationLink.CreateSelfLink(new Uri(val, UriKind.RelativeOrAbsolute)));
}
else if (!FeedUtils.IsXmlns(name, ns))
{
if (this.preserveAttributeExtensions)
{
feed.AttributeExtensions.Add(new XmlQualifiedName(name, ns), val);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
}
}
}
}
string feedTitle = reader.ReadElementString();
feed.Title = new TextSyndicationContent(feedTitle);
result.SourceFeed = feed;
}
else
{
bool parsedExtension = this.serializeExtensionsAsAtom && this.atomSerializer.TryParseItemElementFrom(reader, result);
if (!parsedExtension)
{
parsedExtension = TryParseElement(reader, result, this.Version);
}
if (!parsedExtension)
{
if (this.preserveElementExtensions)
{
CreateBufferIfRequiredAndWriteNode(ref buffer, ref extWriter, reader, this.maxExtensionSize);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
reader.Skip();
}
}
}
}
LoadElementExtensions(buffer, extWriter, result);
}
finally
{
if (extWriter != null)
{
((IDisposable) extWriter).Dispose();
}
}
reader.ReadEndElement(); // item
if (!readAlternateLink && fallbackAlternateLink != null)
{
result.Links.Add(SyndicationLink.CreateAlternateLink(new Uri(fallbackAlternateLink, UriKind.RelativeOrAbsolute)));
readAlternateLink = true;
}
// if there's no content and no alternate link set the summary as the item content
if (result.Content == null && !readAlternateLink)
{
result.Content = result.Summary;
result.Summary = null;
}
}
}
catch (FormatException e)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new XmlException(FeedUtils.AddLineInfo(reader, SR.ErrorParsingItem), e));
}
catch (ArgumentException e)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new XmlException(FeedUtils.AddLineInfo(reader, SR.ErrorParsingItem), e));
}
}
SyndicationLink ReadMediaEnclosure(XmlReader reader, Uri baseUri)
{
SyndicationLink link = new SyndicationLink();
link.BaseUri = baseUri;
link.RelationshipType = Rss20Constants.EnclosureTag;
bool isEmptyElement = reader.IsEmptyElement;
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
string ns = reader.NamespaceURI;
string name = reader.LocalName;
if (name == "base" && ns == Atom10FeedFormatter.XmlNs)
{
link.BaseUri = FeedUtils.CombineXmlBase(link.BaseUri, reader.Value);
continue;
}
if (FeedUtils.IsXmlns(name, ns))
{
continue;
}
string val = reader.Value;
if (name == Rss20Constants.UrlTag && ns == Rss20Constants.Rss20Namespace)
{
link.Uri = new Uri(val, UriKind.RelativeOrAbsolute);
}
else if (name == Rss20Constants.TypeTag && ns == Rss20Constants.Rss20Namespace)
{
link.MediaType = val;
}
else if (name == Rss20Constants.LengthTag && ns == Rss20Constants.Rss20Namespace)
{
link.Length = !string.IsNullOrEmpty(val) ? Convert.ToInt64(val, CultureInfo.InvariantCulture.NumberFormat) : 0;
}
else if (!FeedUtils.IsXmlns(name, ns))
{
if (this.preserveAttributeExtensions)
{
link.AttributeExtensions.Add(new XmlQualifiedName(name, ns), val);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
}
}
}
}
reader.ReadStartElement(Rss20Constants.EnclosureTag, Rss20Constants.Rss20Namespace);
if (!isEmptyElement)
{
reader.ReadEndElement();
}
return link;
}
SyndicationPerson ReadPerson(XmlReader reader, SyndicationFeed feed)
{
SyndicationPerson result = CreatePerson(feed);
ReadPerson(reader, result);
return result;
}
SyndicationPerson ReadPerson(XmlReader reader, SyndicationItem item)
{
SyndicationPerson result = CreatePerson(item);
ReadPerson(reader, result);
return result;
}
void ReadPerson(XmlReader reader, SyndicationPerson person)
{
bool isEmpty = reader.IsEmptyElement;
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
string ns = reader.NamespaceURI;
string name = reader.LocalName;
if (FeedUtils.IsXmlns(name, ns))
{
continue;
}
string val = reader.Value;
if (!TryParseAttribute(name, ns, val, person, this.Version))
{
if (this.preserveAttributeExtensions)
{
person.AttributeExtensions.Add(new XmlQualifiedName(name, ns), val);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
}
}
}
}
reader.ReadStartElement();
if (!isEmpty)
{
string email = reader.ReadString();
reader.ReadEndElement();
person.Email = email;
}
}
void ReadXml(XmlReader reader, SyndicationFeed result)
{
try
{
string baseUri = null;
reader.MoveToContent();
string version = reader.GetAttribute(Rss20Constants.VersionTag, Rss20Constants.Rss20Namespace);
if (version != Rss20Constants.Version)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new NotSupportedException(FeedUtils.AddLineInfo(reader, (SR.GetString(SR.UnsupportedRssVersion, version)))));
}
if (reader.AttributeCount > 1)
{
string tmp = reader.GetAttribute("base", Atom10FeedFormatter.XmlNs);
if (!string.IsNullOrEmpty(tmp))
{
baseUri = tmp;
}
}
reader.ReadStartElement();
reader.MoveToContent();
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
string ns = reader.NamespaceURI;
string name = reader.LocalName;
if (name == "base" && ns == Atom10FeedFormatter.XmlNs)
{
baseUri = reader.Value;
continue;
}
if (FeedUtils.IsXmlns(name, ns) || FeedUtils.IsXmlSchemaType(name, ns))
{
continue;
}
string val = reader.Value;
if (!TryParseAttribute(name, ns, val, result, this.Version))
{
if (this.preserveAttributeExtensions)
{
result.AttributeExtensions.Add(new XmlQualifiedName(name, ns), val);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
}
}
}
}
if (!string.IsNullOrEmpty(baseUri))
{
result.BaseUri = new Uri(baseUri, UriKind.RelativeOrAbsolute);
}
bool areAllItemsRead = true;
bool readItemsAtLeastOnce = false;
reader.ReadStartElement(Rss20Constants.ChannelTag, Rss20Constants.Rss20Namespace);
XmlBuffer buffer = null;
XmlDictionaryWriter extWriter = null;
try
{
while (reader.IsStartElement())
{
if (reader.IsStartElement(Rss20Constants.TitleTag, Rss20Constants.Rss20Namespace))
{
result.Title = new TextSyndicationContent(reader.ReadElementString());
}
else if (reader.IsStartElement(Rss20Constants.LinkTag, Rss20Constants.Rss20Namespace))
{
result.Links.Add(ReadAlternateLink(reader, result.BaseUri));
}
else if (reader.IsStartElement(Rss20Constants.DescriptionTag, Rss20Constants.Rss20Namespace))
{
result.Description = new TextSyndicationContent(reader.ReadElementString());
}
else if (reader.IsStartElement(Rss20Constants.LanguageTag, Rss20Constants.Rss20Namespace))
{
result.Language = reader.ReadElementString();
}
else if (reader.IsStartElement(Rss20Constants.CopyrightTag, Rss20Constants.Rss20Namespace))
{
result.Copyright = new TextSyndicationContent(reader.ReadElementString());
}
else if (reader.IsStartElement(Rss20Constants.ManagingEditorTag, Rss20Constants.Rss20Namespace))
{
result.Authors.Add(ReadPerson(reader, result));
}
else if (reader.IsStartElement(Rss20Constants.LastBuildDateTag, Rss20Constants.Rss20Namespace))
{
bool canReadContent = !reader.IsEmptyElement;
reader.ReadStartElement();
if (canReadContent)
{
string str = reader.ReadString();
if (!string.IsNullOrEmpty(str))
{
result.LastUpdatedTime = DateFromString(str, reader);
}
reader.ReadEndElement();
}
}
else if (reader.IsStartElement(Rss20Constants.CategoryTag, Rss20Constants.Rss20Namespace))
{
result.Categories.Add(ReadCategory(reader, result));
}
else if (reader.IsStartElement(Rss20Constants.GeneratorTag, Rss20Constants.Rss20Namespace))
{
result.Generator = reader.ReadElementString();
}
else if (reader.IsStartElement(Rss20Constants.ImageTag, Rss20Constants.Rss20Namespace))
{
reader.ReadStartElement();
while (reader.IsStartElement())
{
if (reader.IsStartElement(Rss20Constants.UrlTag, Rss20Constants.Rss20Namespace))
{
result.ImageUrl = new Uri(reader.ReadElementString(), UriKind.RelativeOrAbsolute);
}
else
{
// ignore other content
TraceSyndicationElementIgnoredOnRead(reader);
reader.Skip();
}
}
reader.ReadEndElement(); // image
}
else if (reader.IsStartElement(Rss20Constants.ItemTag, Rss20Constants.Rss20Namespace))
{
if (readItemsAtLeastOnce)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperWarning(new InvalidOperationException(SR.GetString(SR.FeedHasNonContiguousItems, this.GetType().ToString())));
}
result.Items = ReadItems(reader, result, out areAllItemsRead);
readItemsAtLeastOnce = true;
// if the derived class is reading the items lazily, then stop reading from the stream
if (!areAllItemsRead)
{
break;
}
}
else
{
bool parsedExtension = this.serializeExtensionsAsAtom && this.atomSerializer.TryParseFeedElementFrom(reader, result);
if (!parsedExtension)
{
parsedExtension = TryParseElement(reader, result, this.Version);
}
if (!parsedExtension)
{
if (preserveElementExtensions)
{
CreateBufferIfRequiredAndWriteNode(ref buffer, ref extWriter, reader, this.maxExtensionSize);
}
else
{
TraceSyndicationElementIgnoredOnRead(reader);
reader.Skip();
}
}
}
}
LoadElementExtensions(buffer, extWriter, result);
}
finally
{
if (extWriter != null)
{
((IDisposable) extWriter).Dispose();
}
}
if (areAllItemsRead)
{
reader.ReadEndElement(); // channel
reader.ReadEndElement(); // rss
}
}
catch (FormatException e)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new XmlException(FeedUtils.AddLineInfo(reader, SR.ErrorParsingFeed), e));
}
catch (ArgumentException e)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new XmlException(FeedUtils.AddLineInfo(reader, SR.ErrorParsingFeed), e));
}
}
void WriteAlternateLink(XmlWriter writer, SyndicationLink link, Uri baseUri)
{
writer.WriteStartElement(Rss20Constants.LinkTag, Rss20Constants.Rss20Namespace);
Uri baseUriToWrite = FeedUtils.GetBaseUriToWrite(baseUri, link.BaseUri);
if (baseUriToWrite != null)
{
writer.WriteAttributeString("xml", "base", Atom10FeedFormatter.XmlNs, FeedUtils.GetUriString(baseUriToWrite));
}
link.WriteAttributeExtensions(writer, SyndicationVersions.Rss20);
writer.WriteString(FeedUtils.GetUriString(link.Uri));
writer.WriteEndElement();
}
void WriteCategory(XmlWriter writer, SyndicationCategory category)
{
if (category == null)
{
return;
}
writer.WriteStartElement(Rss20Constants.CategoryTag, Rss20Constants.Rss20Namespace);
WriteAttributeExtensions(writer, category, this.Version);
if (!string.IsNullOrEmpty(category.Scheme) && !category.AttributeExtensions.ContainsKey(Rss20Domain))
{
writer.WriteAttributeString(Rss20Constants.DomainTag, Rss20Constants.Rss20Namespace, category.Scheme);
}
writer.WriteString(category.Name);
writer.WriteEndElement();
}
void WriteFeed(XmlWriter writer)
{
if (this.Feed == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new InvalidOperationException(SR.GetString(SR.FeedFormatterDoesNotHaveFeed)));
}
if (this.serializeExtensionsAsAtom)
{
writer.WriteAttributeString("xmlns", Atom10Constants.Atom10Prefix, null, Atom10Constants.Atom10Namespace);
}
writer.WriteAttributeString(Rss20Constants.VersionTag, Rss20Constants.Version);
writer.WriteStartElement(Rss20Constants.ChannelTag, Rss20Constants.Rss20Namespace);
if (this.Feed.BaseUri != null)
{
writer.WriteAttributeString("xml", "base", Atom10FeedFormatter.XmlNs, FeedUtils.GetUriString(this.Feed.BaseUri));
}
WriteAttributeExtensions(writer, this.Feed, this.Version);
string title = this.Feed.Title != null ? this.Feed.Title.Text : string.Empty;
writer.WriteElementString(Rss20Constants.TitleTag, Rss20Constants.Rss20Namespace, title);
SyndicationLink alternateLink = null;
for (int i = 0; i < this.Feed.Links.Count; ++i)
{
if (this.Feed.Links[i].RelationshipType == Atom10Constants.AlternateTag)
{
alternateLink = this.Feed.Links[i];
WriteAlternateLink(writer, alternateLink, this.Feed.BaseUri);
break;
}
}
string description = this.Feed.Description != null ? this.Feed.Description.Text : string.Empty;
writer.WriteElementString(Rss20Constants.DescriptionTag, Rss20Constants.Rss20Namespace, description);
if (this.Feed.Language != null)
{
writer.WriteElementString(Rss20Constants.LanguageTag, this.Feed.Language);
}
if (this.Feed.Copyright != null)
{
writer.WriteElementString(Rss20Constants.CopyrightTag, Rss20Constants.Rss20Namespace, this.Feed.Copyright.Text);
}
// if there's a single author with an email address, then serialize as the managingEditor
// else serialize the authors as Atom extensions
#pragma warning disable 56506 // Microsoft: this.Feed.Authors is never null
if ((this.Feed.Authors.Count == 1) && (this.Feed.Authors[0].Email != null))
#pragma warning restore 56506
{
WritePerson(writer, Rss20Constants.ManagingEditorTag, this.Feed.Authors[0]);
}
else
{
if (serializeExtensionsAsAtom)
{
this.atomSerializer.WriteFeedAuthorsTo(writer, this.Feed.Authors);
}
else
{
TraceExtensionsIgnoredOnWrite(SR.FeedAuthorsIgnoredOnWrite);
}
}
if (this.Feed.LastUpdatedTime > DateTimeOffset.MinValue)
{
writer.WriteStartElement(Rss20Constants.LastBuildDateTag);
writer.WriteString(AsString(this.Feed.LastUpdatedTime));
writer.WriteEndElement();
}
#pragma warning disable 56506 // Microsoft: this.Feed.Categories is never null
for (int i = 0; i < this.Feed.Categories.Count; ++i)
#pragma warning restore 56506
{
WriteCategory(writer, this.Feed.Categories[i]);
}
if (!string.IsNullOrEmpty(this.Feed.Generator))
{
writer.WriteElementString(Rss20Constants.GeneratorTag, this.Feed.Generator);
}
#pragma warning disable 56506 // Microsoft: this.Feed.Contributors is never null
if (this.Feed.Contributors.Count > 0)
#pragma warning restore 56506
{
if (serializeExtensionsAsAtom)
{
this.atomSerializer.WriteFeedContributorsTo(writer, this.Feed.Contributors);
}
else
{
TraceExtensionsIgnoredOnWrite(SR.FeedContributorsIgnoredOnWrite);
}
}
if (this.Feed.ImageUrl != null)
{
writer.WriteStartElement(Rss20Constants.ImageTag);
writer.WriteElementString(Rss20Constants.UrlTag, FeedUtils.GetUriString(this.Feed.ImageUrl));
writer.WriteElementString(Rss20Constants.TitleTag, Rss20Constants.Rss20Namespace, title);
string imgAlternateLink = (alternateLink != null) ? FeedUtils.GetUriString(alternateLink.Uri) : string.Empty;
writer.WriteElementString(Rss20Constants.LinkTag, Rss20Constants.Rss20Namespace, imgAlternateLink);
writer.WriteEndElement(); // image
}
if (serializeExtensionsAsAtom)
{
this.atomSerializer.WriteElement(writer, Atom10Constants.IdTag, this.Feed.Id);
// dont write out the 1st alternate link since that would have been written out anyway
bool isFirstAlternateLink = true;
for (int i = 0; i < this.Feed.Links.Count; ++i)
{
if (this.Feed.Links[i].RelationshipType == Atom10Constants.AlternateTag && isFirstAlternateLink)
{
isFirstAlternateLink = false;
continue;
}
this.atomSerializer.WriteLink(writer, this.Feed.Links[i], this.Feed.BaseUri);
}
}
else
{
if (this.Feed.Id != null)
{
TraceExtensionsIgnoredOnWrite(SR.FeedIdIgnoredOnWrite);
}
if (this.Feed.Links.Count > 1)
{
TraceExtensionsIgnoredOnWrite(SR.FeedLinksIgnoredOnWrite);
}
}
WriteElementExtensions(writer, this.Feed, this.Version);
WriteItems(writer, this.Feed.Items, this.Feed.BaseUri);
writer.WriteEndElement(); // channel
}
void WriteItemContents(XmlWriter writer, SyndicationItem item, Uri feedBaseUri)
{
Uri baseUriToWrite = FeedUtils.GetBaseUriToWrite(feedBaseUri, item.BaseUri);
if (baseUriToWrite != null)
{
writer.WriteAttributeString("xml", "base", Atom10FeedFormatter.XmlNs, FeedUtils.GetUriString(baseUriToWrite));
}
WriteAttributeExtensions(writer, item, this.Version);
string guid = item.Id ?? string.Empty;
bool isPermalink = false;
SyndicationLink firstAlternateLink = null;
for (int i = 0; i < item.Links.Count; ++i)
{
if (item.Links[i].RelationshipType == Atom10Constants.AlternateTag)
{
if (firstAlternateLink == null)
{
firstAlternateLink = item.Links[i];
}
if (guid == FeedUtils.GetUriString(item.Links[i].Uri))
{
isPermalink = true;
break;
}
}
}
if (!string.IsNullOrEmpty(guid))
{
writer.WriteStartElement(Rss20Constants.GuidTag);
if (isPermalink)
{
writer.WriteAttributeString(Rss20Constants.IsPermaLinkTag, "true");
}
else
{
writer.WriteAttributeString(Rss20Constants.IsPermaLinkTag, "false");
}
writer.WriteString(guid);
writer.WriteEndElement();
}
if (firstAlternateLink != null)
{
WriteAlternateLink(writer, firstAlternateLink, (item.BaseUri != null ? item.BaseUri : feedBaseUri));
}
#pragma warning disable 56506 // Microsoft, item.Authors is never null
if (item.Authors.Count == 1 && !string.IsNullOrEmpty(item.Authors[0].Email))
#pragma warning restore 56506
{
WritePerson(writer, Rss20Constants.AuthorTag, item.Authors[0]);
}
else
{
if (serializeExtensionsAsAtom)
{
this.atomSerializer.WriteItemAuthorsTo(writer, item.Authors);
}
else
{
TraceExtensionsIgnoredOnWrite(SR.ItemAuthorsIgnoredOnWrite);
}
}
#pragma warning disable 56506 // Microsoft, item.Categories is never null
for (int i = 0; i < item.Categories.Count; ++i)
#pragma warning restore 56506
{
WriteCategory(writer, item.Categories[i]);
}
bool serializedTitle = false;
if (item.Title != null)
{
writer.WriteElementString(Rss20Constants.TitleTag, item.Title.Text);
serializedTitle = true;
}
bool serializedContentAsDescription = false;
TextSyndicationContent summary = item.Summary;
if (summary == null)
{
summary = (item.Content as TextSyndicationContent);
serializedContentAsDescription = (summary != null);
}
// the spec requires the wire to have a title or a description
if (!serializedTitle && summary == null)
{
summary = new TextSyndicationContent(string.Empty);
}
if (summary != null)
{
writer.WriteElementString(Rss20Constants.DescriptionTag, Rss20Constants.Rss20Namespace, summary.Text);
}
if (item.SourceFeed != null)
{
writer.WriteStartElement(Rss20Constants.SourceTag, Rss20Constants.Rss20Namespace);
WriteAttributeExtensions(writer, item.SourceFeed, this.Version);
SyndicationLink selfLink = null;
for (int i = 0; i < item.SourceFeed.Links.Count; ++i)
{
if (item.SourceFeed.Links[i].RelationshipType == Atom10Constants.SelfTag)
{
selfLink = item.SourceFeed.Links[i];
break;
}
}
if (selfLink != null && !item.SourceFeed.AttributeExtensions.ContainsKey(Rss20Url))
{
writer.WriteAttributeString(Rss20Constants.UrlTag, Rss20Constants.Rss20Namespace, FeedUtils.GetUriString(selfLink.Uri));
}
string title = (item.SourceFeed.Title != null) ? item.SourceFeed.Title.Text : string.Empty;
writer.WriteString(title);
writer.WriteEndElement();
}
if (item.PublishDate > DateTimeOffset.MinValue)
{
writer.WriteElementString(Rss20Constants.PubDateTag, Rss20Constants.Rss20Namespace, AsString(item.PublishDate));
}
// serialize the enclosures
SyndicationLink firstEnclosureLink = null;
bool passedFirstAlternateLink = false;
bool isLinkIgnored = false;
for (int i = 0; i < item.Links.Count; ++i)
{
if (item.Links[i].RelationshipType == Rss20Constants.EnclosureTag)
{
if (firstEnclosureLink == null)
{
firstEnclosureLink = item.Links[i];
WriteMediaEnclosure(writer, item.Links[i], item.BaseUri);
continue;
}
}
else if (item.Links[i].RelationshipType == Atom10Constants.AlternateTag)
{
if (!passedFirstAlternateLink)
{
passedFirstAlternateLink = true;
continue;
}
}
if (this.serializeExtensionsAsAtom)
{
this.atomSerializer.WriteLink(writer, item.Links[i], item.BaseUri);
}
else
{
isLinkIgnored = true;
}
}
if (isLinkIgnored)
{
TraceExtensionsIgnoredOnWrite(SR.ItemLinksIgnoredOnWrite);
}
if (item.LastUpdatedTime > DateTimeOffset.MinValue)
{
if (this.serializeExtensionsAsAtom)
{
this.atomSerializer.WriteItemLastUpdatedTimeTo(writer, item.LastUpdatedTime);
}
else
{
TraceExtensionsIgnoredOnWrite(SR.ItemLastUpdatedTimeIgnoredOnWrite);
}
}
if (serializeExtensionsAsAtom)
{
this.atomSerializer.WriteContentTo(writer, Atom10Constants.RightsTag, item.Copyright);
}
else
{
TraceExtensionsIgnoredOnWrite(SR.ItemCopyrightIgnoredOnWrite);
}
if (!serializedContentAsDescription)
{
if (serializeExtensionsAsAtom)
{
this.atomSerializer.WriteContentTo(writer, Atom10Constants.ContentTag, item.Content);
}
else
{
TraceExtensionsIgnoredOnWrite(SR.ItemContentIgnoredOnWrite);
}
}
#pragma warning disable 56506 // Microsoft, item.COntributors is never null
if (item.Contributors.Count > 0)
#pragma warning restore 56506
{
if (serializeExtensionsAsAtom)
{
this.atomSerializer.WriteItemContributorsTo(writer, item.Contributors);
}
else
{
TraceExtensionsIgnoredOnWrite(SR.ItemContributorsIgnoredOnWrite);
}
}
WriteElementExtensions(writer, item, this.Version);
}
void WriteMediaEnclosure(XmlWriter writer, SyndicationLink link, Uri baseUri)
{
writer.WriteStartElement(Rss20Constants.EnclosureTag, Rss20Constants.Rss20Namespace);
Uri baseUriToWrite = FeedUtils.GetBaseUriToWrite(baseUri, link.BaseUri);
if (baseUriToWrite != null)
{
writer.WriteAttributeString("xml", "base", Atom10FeedFormatter.XmlNs, FeedUtils.GetUriString(baseUriToWrite));
}
link.WriteAttributeExtensions(writer, SyndicationVersions.Rss20);
if (!link.AttributeExtensions.ContainsKey(Rss20Url))
{
writer.WriteAttributeString(Rss20Constants.UrlTag, Rss20Constants.Rss20Namespace, FeedUtils.GetUriString(link.Uri));
}
if (link.MediaType != null && !link.AttributeExtensions.ContainsKey(Rss20Type))
{
writer.WriteAttributeString(Rss20Constants.TypeTag, Rss20Constants.Rss20Namespace, link.MediaType);
}
if (link.Length != 0 && !link.AttributeExtensions.ContainsKey(Rss20Length))
{
writer.WriteAttributeString(Rss20Constants.LengthTag, Rss20Constants.Rss20Namespace, Convert.ToString(link.Length, CultureInfo.InvariantCulture));
}
writer.WriteEndElement();
}
void WritePerson(XmlWriter writer, string elementTag, SyndicationPerson person)
{
writer.WriteStartElement(elementTag, Rss20Constants.Rss20Namespace);
WriteAttributeExtensions(writer, person, this.Version);
writer.WriteString(person.Email);
writer.WriteEndElement();
}
}
[TypeForwardedFrom("System.ServiceModel.Web, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35")]
[XmlRoot(ElementName = Rss20Constants.RssTag, Namespace = Rss20Constants.Rss20Namespace)]
public class Rss20FeedFormatter<TSyndicationFeed> : Rss20FeedFormatter
where TSyndicationFeed : SyndicationFeed, new ()
{
// constructors
public Rss20FeedFormatter()
: base(typeof(TSyndicationFeed))
{
}
public Rss20FeedFormatter(TSyndicationFeed feedToWrite)
: base(feedToWrite)
{
}
public Rss20FeedFormatter(TSyndicationFeed feedToWrite, bool serializeExtensionsAsAtom)
: base(feedToWrite, serializeExtensionsAsAtom)
{
}
protected override SyndicationFeed CreateFeedInstance()
{
return new TSyndicationFeed();
}
}
}
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