//
// Rss20ItemFormatter.cs
//
// Author:
// Atsushi Enomoto <atsushi@ximian.com>
//
// Copyright (C) 2007 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
namespace System.ServiceModel.Syndication{
static class XmlReaderExtensions
{
public static bool IsTextNode (this XmlReader r)
{
switch (r.NodeType) {
case XmlNodeType.Text:
case XmlNodeType.CDATA:
case XmlNodeType.Whitespace:
case XmlNodeType.SignificantWhitespace:
return true;
}
return false;
}
}
[XmlRoot ("item", Namespace = "")]
public class Rss20ItemFormatter : SyndicationItemFormatter, IXmlSerializable
{
const string AtomNamespace ="http://www.w3.org/2005/Atom";
bool ext_atom_serialization, preserve_att_ext = true, preserve_elem_ext = true;
Type item_type;
public Rss20ItemFormatter ()
{
ext_atom_serialization = true;
}
public Rss20ItemFormatter (SyndicationItem itemToWrite)
: this (itemToWrite, true)
{
}
public Rss20ItemFormatter (SyndicationItem itemToWrite, bool serializeExtensionsAsAtom)
: base (itemToWrite)
{
ext_atom_serialization = serializeExtensionsAsAtom;
}
public Rss20ItemFormatter (Type itemTypeToCreate)
{
if (itemTypeToCreate == null)
throw new ArgumentNullException ("itemTypeToCreate");
item_type = itemTypeToCreate;
}
public bool SerializeExtensionsAsAtom {
get { return ext_atom_serialization; }
set { ext_atom_serialization = value; }
}
protected Type ItemType {
get { return item_type; }
}
public bool PreserveAttributeExtensions {
get { return preserve_att_ext; }
set { preserve_att_ext = value; }
}
public bool PreserveElementExtensions {
get { return preserve_elem_ext; }
set { preserve_elem_ext = value; }
}
public override string Version {
get { return "Rss20"; }
}
protected override SyndicationItem CreateItemInstance ()
{
return new SyndicationItem ();
}
public override bool CanRead (XmlReader reader)
{
if (reader == null)
throw new ArgumentNullException ("reader");
reader.MoveToContent ();
return reader.IsStartElement ("item", String.Empty);
}
public override void ReadFrom (XmlReader reader)
{
if (!CanRead (reader))
throw new XmlException (String.Format ("Element '{0}' in namespace '{1}' is not accepted by this syndication formatter", reader.LocalName, reader.NamespaceURI));
ReadXml (reader, true);
}
public override void WriteTo (XmlWriter writer)
{
WriteXml (writer, true);
}
void IXmlSerializable.ReadXml (XmlReader reader)
{
ReadXml (reader, false);
}
void IXmlSerializable.WriteXml (XmlWriter writer)
{
WriteXml (writer, false);
}
XmlSchema IXmlSerializable.GetSchema ()
{
return null;
}
// read
void ReadXml (XmlReader reader, bool fromSerializable)
{
if (reader == null)
throw new ArgumentNullException ("reader");
SetItem (CreateItemInstance ());
reader.MoveToContent ();
if (PreserveAttributeExtensions && reader.MoveToFirstAttribute ()) {
do {
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/")
continue;
if (!TryParseAttribute (reader.LocalName, reader.NamespaceURI, reader.Value, Item, Version))
Item.AttributeExtensions.Add (new XmlQualifiedName (reader.LocalName, reader.NamespaceURI), reader.Value);
} while (reader.MoveToNextAttribute ());
}
reader.ReadStartElement ();
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (reader.NodeType != XmlNodeType.Element)
throw new XmlException ("Only element node is expected under 'item' element");
if (reader.NamespaceURI == String.Empty)
switch (reader.LocalName) {
case "title":
Item.Title = ReadTextSyndicationContent (reader);
continue;
case "link":
SyndicationLink l = Item.CreateLink ();
ReadLink (reader, l);
Item.Links.Add (l);
continue;
case "description":
Item.Summary = ReadTextSyndicationContent (reader);
continue;
case "author":
SyndicationPerson p = Item.CreatePerson ();
ReadPerson (reader, p);
Item.Authors.Add (p);
continue;
case "category":
SyndicationCategory c = Item.CreateCategory ();
ReadCategory (reader, c);
Item.Categories.Add (c);
continue;
// case "comments": // treated as extension ...
case "enclosure":
l = Item.CreateLink ();
ReadEnclosure (reader, l);
Item.Links.Add (l);
continue;
case "guid":
Item.AddPermalink (CreateUri (reader.ReadElementContentAsString ()));
continue;
case "pubDate":
// FIXME: somehow DateTimeOffset causes the runtime crash.
reader.ReadElementContentAsString ();
// Item.PublishDate = FromRFC822DateString (reader.ReadElementContentAsString ());
continue;
case "source":
Item.SourceFeed = new SyndicationFeed ();
ReadSourceFeed (reader, Item.SourceFeed);
continue;
}
else if (SerializeExtensionsAsAtom && reader.NamespaceURI == AtomNamespace) {
switch (reader.LocalName) {
case "contributor":
SyndicationPerson p = Item.CreatePerson ();
ReadPersonAtom10 (reader, p);
Item.Contributors.Add (p);
continue;
case "updated":
// FIXME: somehow DateTimeOffset causes the runtime crash.
reader.ReadElementContentAsString ();
// Item.LastUpdatedTime = XmlConvert.ToDateTimeOffset (reader.ReadElementContentAsString ());
continue;
case "rights":
Item.Copyright = ReadTextSyndicationContent (reader);
continue;
case "content":
if (reader.GetAttribute ("src") != null) {
Item.Content = new UrlSyndicationContent (CreateUri (reader.GetAttribute ("src")), reader.GetAttribute ("type"));
reader.Skip ();
continue;
}
switch (reader.GetAttribute ("type")) {
case "text":
case "html":
case "xhtml":
Item.Content = ReadTextSyndicationContent (reader);
continue;
default:
SyndicationContent content;
if (!TryParseContent (reader, Item, reader.GetAttribute ("type"), Version, out content))
Item.Content = new XmlSyndicationContent (reader);
continue;
}
}
}
if (!TryParseElement (reader, Item, Version)) {
if (PreserveElementExtensions)
// FIXME: what to specify for maxExtensionSize
LoadElementExtensions (reader, Item, int.MaxValue);
else
reader.Skip ();
}
}
reader.ReadEndElement (); // </item>
}
TextSyndicationContent ReadTextSyndicationContent (XmlReader reader)
{
TextSyndicationContentKind kind = TextSyndicationContentKind.Plaintext;
switch (reader.GetAttribute ("type")) {
case "html":
kind = TextSyndicationContentKind.Html;
break;
case "xhtml":
kind = TextSyndicationContentKind.XHtml;
break;
}
string text = reader.ReadElementContentAsString ();
TextSyndicationContent t = new TextSyndicationContent (text, kind);
return t;
}
void ReadCategory (XmlReader reader, SyndicationCategory category)
{
if (reader.MoveToFirstAttribute ()) {
do {
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/")
continue;
if (reader.NamespaceURI == String.Empty) {
switch (reader.LocalName) {
case "domain":
category.Scheme = reader.Value;
continue;
}
}
if (PreserveAttributeExtensions)
if (!TryParseAttribute (reader.LocalName, reader.NamespaceURI, reader.Value, category, Version))
category.AttributeExtensions.Add (new XmlQualifiedName (reader.LocalName, reader.NamespaceURI), reader.Value);
} while (reader.MoveToNextAttribute ());
reader.MoveToElement ();
}
if (!reader.IsEmptyElement) {
reader.Read ();
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (reader.IsTextNode ())
category.Name += reader.Value;
else if (!TryParseElement (reader, category, Version)) {
if (PreserveElementExtensions)
// FIXME: what should be used for maxExtenswionSize
LoadElementExtensions (reader, category, int.MaxValue);
else
reader.Skip ();
}
reader.Read ();
}
}
reader.Read (); // </category> or <category ... />
}
// SyndicationLink.CreateMediaEnclosureLink() is almost
// useless here since it cannot handle extension attributes
// in straightforward way (it I use it, I have to iterate
// attributes twice just to read extensions).
void ReadEnclosure (XmlReader reader, SyndicationLink link)
{
link.RelationshipType = "enclosure";
if (PreserveAttributeExtensions && reader.MoveToFirstAttribute ()) {
do {
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/")
continue;
if (reader.NamespaceURI == String.Empty) {
switch (reader.LocalName) {
case "url":
link.Uri = CreateUri (reader.Value);
continue;
case "type":
link.MediaType = reader.Value;
continue;
case "length":
link.Length = XmlConvert.ToInt64 (reader.Value);
continue;
}
}
if (!TryParseAttribute (reader.LocalName, reader.NamespaceURI, reader.Value, link, Version))
link.AttributeExtensions.Add (new XmlQualifiedName (reader.LocalName, reader.NamespaceURI), reader.Value);
} while (reader.MoveToNextAttribute ());
reader.MoveToElement ();
}
// Actually .NET fails to read extension here.
if (!reader.IsEmptyElement) {
reader.Read ();
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (!TryParseElement (reader, link, Version)) {
if (PreserveElementExtensions)
// FIXME: what should be used for maxExtenswionSize
LoadElementExtensions (reader, link, int.MaxValue);
else
reader.Skip ();
}
}
}
reader.Read (); // </enclosure> or <enclosure ... />
}
void ReadLink (XmlReader reader, SyndicationLink link)
{
if (PreserveAttributeExtensions && reader.MoveToFirstAttribute ()) {
do {
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/")
continue;
if (!TryParseAttribute (reader.LocalName, reader.NamespaceURI, reader.Value, link, Version))
link.AttributeExtensions.Add (new XmlQualifiedName (reader.LocalName, reader.NamespaceURI), reader.Value);
} while (reader.MoveToNextAttribute ());
reader.MoveToElement ();
}
if (!reader.IsEmptyElement) {
string url = null;
reader.Read ();
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (reader.IsTextNode ())
url += reader.Value;
else if (!TryParseElement (reader, link, Version)) {
if (PreserveElementExtensions)
// FIXME: what should be used for maxExtenswionSize
LoadElementExtensions (reader, link, int.MaxValue);
else
reader.Skip ();
}
reader.Read ();
}
link.Uri = CreateUri (url);
}
reader.Read (); // </link> or <link ... />
}
void ReadPerson (XmlReader reader, SyndicationPerson person)
{
if (PreserveAttributeExtensions && reader.MoveToFirstAttribute ()) {
do {
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/")
continue;
if (!TryParseAttribute (reader.LocalName, reader.NamespaceURI, reader.Value, person, Version))
person.AttributeExtensions.Add (new XmlQualifiedName (reader.LocalName, reader.NamespaceURI), reader.Value);
} while (reader.MoveToNextAttribute ());
reader.MoveToElement ();
}
if (!reader.IsEmptyElement) {
reader.Read ();
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (reader.IsTextNode ())
person.Email += reader.Value;
else if (!TryParseElement (reader, person, Version)) {
if (PreserveElementExtensions)
// FIXME: what should be used for maxExtenswionSize
LoadElementExtensions (reader, person, int.MaxValue);
else
reader.Skip ();
}
reader.Read ();
}
}
reader.Read (); // end element or empty element
}
// copied from Atom10ItemFormatter
void ReadPersonAtom10 (XmlReader reader, SyndicationPerson person)
{
if (reader.MoveToFirstAttribute ()) {
do {
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/")
continue;
if (!TryParseAttribute (reader.LocalName, reader.NamespaceURI, reader.Value, person, Version) && PreserveAttributeExtensions)
person.AttributeExtensions.Add (new XmlQualifiedName (reader.LocalName, reader.NamespaceURI), reader.Value);
} while (reader.MoveToNextAttribute ());
reader.MoveToElement ();
}
if (!reader.IsEmptyElement) {
reader.Read ();
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (reader.NodeType == XmlNodeType.Element && reader.NamespaceURI == AtomNamespace) {
switch (reader.LocalName) {
case "name":
person.Name = reader.ReadElementContentAsString ();
continue;
case "uri":
person.Uri = reader.ReadElementContentAsString ();
continue;
case "email":
person.Email = reader.ReadElementContentAsString ();
continue;
}
}
if (!TryParseElement (reader, person, Version)) {
if (PreserveElementExtensions)
// FIXME: what should be used for maxExtenswionSize
LoadElementExtensions (reader, person, int.MaxValue);
else
reader.Skip ();
}
}
}
reader.Read (); // end element or empty element
}
void ReadSourceFeed (XmlReader reader, SyndicationFeed feed)
{
if (reader.MoveToFirstAttribute ()) {
do {
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/")
continue;
if (reader.NamespaceURI == String.Empty) {
switch (reader.LocalName) {
case "url":
feed.Links.Add (new SyndicationLink (CreateUri (reader.Value)));
continue;
}
}
} while (reader.MoveToNextAttribute ());
reader.MoveToElement ();
}
if (!reader.IsEmptyElement) {
reader.Read ();
string title = null;
while (reader.NodeType != XmlNodeType.EndElement) {
if (reader.IsTextNode ())
title += reader.Value;
reader.Skip ();
reader.MoveToContent ();
}
feed.Title = new TextSyndicationContent (title);
}
reader.Read (); // </source> or <source ... />
}
Uri CreateUri (string uri)
{
return new Uri (uri, UriKind.RelativeOrAbsolute);
}
// write
void WriteXml (XmlWriter writer, bool writeRoot)
{
if (writer == null)
throw new ArgumentNullException ("writer");
if (Item == null)
throw new InvalidOperationException ("Syndication item must be set before writing");
if (writeRoot)
writer.WriteStartElement ("item");
if (Item.BaseUri != null)
writer.WriteAttributeString ("xml:base", Item.BaseUri.ToString ());
WriteAttributeExtensions (writer, Item, Version);
if (Item.Id != null) {
writer.WriteStartElement ("guid");
writer.WriteAttributeString ("isPermaLink", "false");
writer.WriteString (Item.Id);
writer.WriteEndElement ();
}
if (Item.Title != null) {
writer.WriteStartElement ("title");
writer.WriteString (Item.Title.Text);
writer.WriteEndElement ();
}
foreach (SyndicationPerson author in Item.Authors)
if (author != null) {
writer.WriteStartElement ("author");
WriteAttributeExtensions (writer, author, Version);
writer.WriteString (author.Email);
WriteElementExtensions (writer, author, Version);
writer.WriteEndElement ();
}
foreach (SyndicationCategory category in Item.Categories)
if (category != null) {
writer.WriteStartElement ("category");
if (category.Scheme != null)
writer.WriteAttributeString ("domain", category.Scheme);
WriteAttributeExtensions (writer, category, Version);
writer.WriteString (category.Name);
WriteElementExtensions (writer, category, Version);
writer.WriteEndElement ();
}
if (Item.Content != null) {
Item.Content.WriteTo (writer, "description", String.Empty);
} else if (Item.Summary != null)
Item.Summary.WriteTo (writer, "description", String.Empty);
else if (Item.Title == null) { // according to the RSS 2.0 spec, either of title or description must exist.
writer.WriteStartElement ("description");
writer.WriteEndElement ();
}
foreach (SyndicationLink link in Item.Links)
switch (link.RelationshipType) {
case "enclosure":
writer.WriteStartElement ("enclosure");
if (link.Uri != null)
writer.WriteAttributeString ("uri", link.Uri.ToString ());
if (link.Length != 0)
writer.WriteAttributeString ("length", XmlConvert.ToString (link.Length));
if (link.MediaType != null)
writer.WriteAttributeString ("type", link.MediaType);
WriteAttributeExtensions (writer, link, Version);
WriteElementExtensions (writer, link, Version);
writer.WriteEndElement ();
break;
default:
writer.WriteStartElement ("link");
WriteAttributeExtensions (writer, link, Version);
writer.WriteString (link.Uri != null ? link.Uri.ToString () : String.Empty);
WriteElementExtensions (writer, link, Version);
writer.WriteEndElement ();
break;
}
if (Item.SourceFeed != null) {
writer.WriteStartElement ("source");
if (Item.SourceFeed.Links.Count > 0) {
Uri u = Item.SourceFeed.Links [0].Uri;
writer.WriteAttributeString ("url", u != null ? u.ToString () : String.Empty);
}
writer.WriteString (Item.SourceFeed.Title != null ? Item.SourceFeed.Title.Text : String.Empty);
writer.WriteEndElement ();
}
if (!Item.PublishDate.Equals (default (DateTimeOffset))) {
writer.WriteStartElement ("pubDate");
writer.WriteString (ToRFC822DateString (Item.PublishDate));
writer.WriteEndElement ();
}
if (SerializeExtensionsAsAtom) {
foreach (SyndicationPerson contributor in Item.Contributors) {
if (contributor != null) {
writer.WriteStartElement ("contributor", AtomNamespace);
WriteAttributeExtensions (writer, contributor, Version);
writer.WriteElementString ("name", AtomNamespace, contributor.Name);
writer.WriteElementString ("uri", AtomNamespace, contributor.Uri);
writer.WriteElementString ("email", AtomNamespace, contributor.Email);
WriteElementExtensions (writer, contributor, Version);
writer.WriteEndElement ();
}
}
if (!Item.LastUpdatedTime.Equals (default (DateTimeOffset))) {
writer.WriteStartElement ("updated", AtomNamespace);
// FIXME: how to handle offset part?
writer.WriteString (XmlConvert.ToString (Item.LastUpdatedTime.DateTime, XmlDateTimeSerializationMode.Local));
writer.WriteEndElement ();
}
if (Item.Copyright != null)
Item.Copyright.WriteTo (writer, "rights", AtomNamespace);
#if false
if (Item.Content != null)
Item.Content.WriteTo (writer, "content", AtomNamespace);
#endif
}
WriteElementExtensions (writer, Item, Version);
if (writeRoot)
writer.WriteEndElement ();
}
// FIXME: DateTimeOffset.ToString() needs another overload.
// When it is implemented, just remove ".DateTime" parts below.
string ToRFC822DateString (DateTimeOffset date)
{
switch (date.DateTime.Kind) {
case DateTimeKind.Utc:
return date.DateTime.ToString ("ddd, dd MMM yyyy HH:mm:ss 'Z'", DateTimeFormatInfo.InvariantInfo);
case DateTimeKind.Local:
StringBuilder sb = new StringBuilder (date.DateTime.ToString ("ddd, dd MMM yyyy HH:mm:ss zzz", DateTimeFormatInfo.InvariantInfo));
sb.Remove (sb.Length - 3, 1);
return sb.ToString (); // remove ':' from +hh:mm
default:
return date.DateTime.ToString ("ddd, dd MMM yyyy HH:mm:ss", DateTimeFormatInfo.InvariantInfo);
}
}
string [] rfc822formats = new string [] {
"ddd, dd MMM yyyy HH:mm:ss 'Z'",
"ddd, dd MMM yyyy HH:mm:ss zzz",
"ddd, dd MMM yyyy HH:mm:ss"};
// FIXME: DateTimeOffset is still incomplete. When it is done,
// simplify the code.
DateTimeOffset FromRFC822DateString (string s)
{
return XmlConvert.ToDateTimeOffset (s, rfc822formats);
}
}
}
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