//
// Rss20FeedFormatter.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.Runtime.Serialization;
using System.Text;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
namespace System.ServiceModel.Syndication{
[XmlRoot ("rss", Namespace = "")]
public class Rss20FeedFormatter : SyndicationFeedFormatter, IXmlSerializable
{
const string AtomNamespace ="http://www.w3.org/2005/Atom";
bool ext_atom_serialization, preserve_att_ext = true, preserve_elem_ext = true;
Type feed_type;
public Rss20FeedFormatter ()
{
ext_atom_serialization = true;
}
public Rss20FeedFormatter (SyndicationFeed feedToWrite)
: this (feedToWrite, true)
{
}
public Rss20FeedFormatter (SyndicationFeed feedToWrite, bool serializeExtensionsAsAtom)
: base (feedToWrite)
{
ext_atom_serialization = serializeExtensionsAsAtom;
}
public Rss20FeedFormatter (Type feedTypeToCreate)
{
if (feedTypeToCreate == null)
throw new ArgumentNullException ("feedTypeToCreate");
feed_type = feedTypeToCreate;
}
public bool SerializeExtensionsAsAtom {
get { return ext_atom_serialization; }
set { ext_atom_serialization = value; }
}
protected Type FeedType {
get { return feed_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 SyndicationFeed CreateFeedInstance ()
{
return new SyndicationFeed ();
}
// hmm, why is it overriden? probably failed API cleanup.
protected internal override void SetFeed (SyndicationFeed feed)
{
base.SetFeed (feed);
}
public override bool CanRead (XmlReader reader)
{
if (reader == null)
throw new ArgumentNullException ("reader");
reader.MoveToContent ();
return reader.IsStartElement ("rss", 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);
}
protected virtual SyndicationItem ReadItem (XmlReader reader, SyndicationFeed feed)
{
Rss20ItemFormatter formatter = new Rss20ItemFormatter();
formatter.ReadFrom (reader);
return formatter.Item;
}
protected virtual IEnumerable<SyndicationItem> ReadItems (XmlReader reader, SyndicationFeed feed, out bool areAllItemsRead)
{
Collection<SyndicationItem> c = new Collection<SyndicationItem> ();
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ())
if (reader.LocalName == "item" && reader.NamespaceURI == String.Empty)
c.Add (ReadItem (reader, feed));
areAllItemsRead = (reader.NodeType == XmlNodeType.EndElement);
return c;
}
protected virtual void WriteItem (XmlWriter writer, SyndicationItem item, Uri feedBaseUri)
{
item.SaveAsRss20 (writer);
}
protected virtual void WriteItems (XmlWriter writer, IEnumerable<SyndicationItem> items, Uri feedBaseUri)
{
if (items == null)
throw new ArgumentNullException ("items");
foreach (SyndicationItem item in items)
WriteItem (writer, item, feedBaseUri);
}
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");
SetFeed (CreateFeedInstance ());
reader.MoveToContent ();
string ver = reader.GetAttribute ("version");
if (ver != "2.0")
throw new NotSupportedException (String.Format ("RSS Version '{0}' is not supported", ver));
if (PreserveAttributeExtensions && reader.MoveToFirstAttribute ()) {
do {
if (reader.NamespaceURI == "http://www.w3.org/2000/xmlns/")
continue;
if (reader.NamespaceURI == String.Empty && reader.LocalName == "version")
continue;
if (!TryParseAttribute (reader.LocalName, reader.NamespaceURI, reader.Value, Feed, Version))
Feed.AttributeExtensions.Add (new XmlQualifiedName (reader.LocalName, reader.NamespaceURI), reader.Value);
} while (reader.MoveToNextAttribute ());
}
reader.ReadStartElement (); // <rss> => <channel>
reader.MoveToContent ();
reader.ReadStartElement ("channel", String.Empty); // <channel> => *
Collection<SyndicationItem> items = null;
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (reader.NodeType != XmlNodeType.Element)
throw new XmlException ("Only element node is expected under 'channel' element");
if (reader.NamespaceURI == String.Empty)
switch (reader.LocalName) {
case "title":
Feed.Title = ReadTextSyndicationContent (reader);
continue;
case "link":
SyndicationLink l = Feed.CreateLink ();
ReadLink (reader, l);
Feed.Links.Add (l);
continue;
case "description":
Feed.Description = ReadTextSyndicationContent (reader);
continue;
case "language":
Feed.Language = reader.ReadElementContentAsString ();
continue;
case "copyright":
Feed.Copyright = ReadTextSyndicationContent (reader);
continue;
case "managingEditor":
SyndicationPerson p = Feed.CreatePerson ();
ReadPerson (reader, p);
Feed.Authors.Add (p);
continue;
case "pubDate":
// FIXME: somehow DateTimeOffset causes the runtime crash.
reader.ReadElementContentAsString ();
// Feed.PublishDate = FromRFC822DateString (reader.ReadElementContentAsString ());
continue;
case "lastBuildDate":
// FIXME: somehow DateTimeOffset causes the runtime crash.
reader.ReadElementContentAsString ();
// Feed.LastUpdatedTime = FromRFC822DateString (reader.ReadElementContentAsString ());
continue;
case "category":
SyndicationCategory c = Feed.CreateCategory ();
ReadCategory (reader, c);
Feed.Categories.Add (c);
continue;
case "generator":
Feed.Generator = reader.ReadElementContentAsString ();
continue;
// "webMaster" "docs" "cloud" "ttl" "image" "rating" "textInput" "skipHours" "skipDays" are not handled.
case "item":
if (items == null) {
items = new Collection<SyndicationItem> ();
Feed.Items = items;
}
items.Add (ReadItem (reader, Feed));
continue;
}
if (!TryParseElement (reader, Feed, Version)) {
if (PreserveElementExtensions)
// FIXME: what to specify for maxExtensionSize
LoadElementExtensions (reader, Feed, int.MaxValue);
else
reader.Skip ();
}
}
reader.ReadEndElement (); // </channel>
reader.ReadEndElement (); // </rss>
}
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 ... />
}
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
}
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 (Feed == null)
throw new InvalidOperationException ("Syndication feed must be set before writing");
if (writeRoot)
writer.WriteStartElement ("rss");
if (SerializeExtensionsAsAtom)
writer.WriteAttributeString ("xmlns", "a10", "http://www.w3.org/2000/xmlns/", AtomNamespace);
writer.WriteAttributeString ("version", "2.0");
writer.WriteStartElement ("channel");
if (Feed.BaseUri != null)
writer.WriteAttributeString ("xml:base", Feed.BaseUri.ToString ());
writer.WriteElementString ("title", String.Empty, Feed.Title != null ? Feed.Title.Text : String.Empty);
writer.WriteElementString ("description", String.Empty, Feed.Description != null ? Feed.Description.Text : String.Empty);
if (Feed.Copyright != null)
writer.WriteElementString ("copyright", String.Empty, Feed.Copyright.Text);
if (!Feed.LastUpdatedTime.Equals (default (DateTimeOffset))) {
writer.WriteStartElement ("lastBuildDate");
writer.WriteString (ToRFC822DateString (Feed.LastUpdatedTime));
writer.WriteEndElement ();
}
if (Feed.Generator != null)
writer.WriteElementString ("generator", String.Empty, Feed.Generator);
if (Feed.ImageUrl != null) {
writer.WriteStartElement ("image");
writer.WriteElementString ("url", String.Empty, Feed.ImageUrl.ToString ());
// FIXME: are they really empty?
writer.WriteElementString ("title", String.Empty, String.Empty);
writer.WriteElementString ("link", String.Empty, String.Empty);
writer.WriteEndElement ();
}
if (Feed.Language != null)
writer.WriteElementString ("language", String.Empty, Feed.Language);
foreach (SyndicationPerson author in Feed.Authors)
if (author != null) {
writer.WriteStartElement ("managingEditor");
WriteAttributeExtensions (writer, author, Version);
writer.WriteString (author.Email);
WriteElementExtensions (writer, author, Version);
writer.WriteEndElement ();
}
foreach (SyndicationCategory category in Feed.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 ();
}
foreach (SyndicationLink link in Feed.Links)
if (link != null) {
writer.WriteStartElement ("link");
WriteAttributeExtensions (writer, link, Version);
writer.WriteString (link.Uri != null ? link.Uri.ToString () : String.Empty);
WriteElementExtensions (writer, link, Version);
writer.WriteEndElement ();
}
WriteItems (writer, Feed.Items, Feed.BaseUri);
if (SerializeExtensionsAsAtom) {
if (Feed.Id != null) {
writer.WriteStartElement ("a10", "id", AtomNamespace);
writer.WriteString (Feed.Id);
writer.WriteEndElement ();
}
foreach (SyndicationPerson contributor in Feed.Contributors) {
if (contributor != null) {
writer.WriteStartElement ("a10", "contributor", AtomNamespace);
WriteAttributeExtensions (writer, contributor, Version);
writer.WriteElementString ("a10", "name", AtomNamespace, contributor.Name);
writer.WriteElementString ("a10", "uri", AtomNamespace, contributor.Uri);
writer.WriteElementString ("a10", "email", AtomNamespace, contributor.Email);
WriteElementExtensions (writer, contributor, Version);
writer.WriteEndElement ();
}
}
}
writer.WriteEndElement (); // </channel>
if (writeRoot)
writer.WriteEndElement (); // </rss>
}
// 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);
}
}
}
}
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