/// <summary>Reads the next RssElement from the stream.</summary>
/// <returns>An RSS Element</returns>
/// <exception cref="InvalidOperationException">RssReader has been closed, and can not be read.</exception>
/// <exception cref="System.IO.FileNotFoundException">RSS file not found.</exception>
/// <exception cref="System.Xml.XmlException">Invalid XML syntax in RSS file.</exception>
/// <exception cref="System.IO.EndOfStreamException">Unable to read an RssElement. Reached the end of the stream.</exception>
public RssElement Read()
{
var readData = false;
var pushElement = true;
RssElement rssElement = null;
var lineNumber = -1;
var linePosition = -1;
if (reader == null)
{
throw new InvalidOperationException("RssReader has been closed, and can not be read.");
}
do
{
pushElement = true;
try
{
readData = reader.Read();
}
catch (EndOfStreamException e)
{
throw new EndOfStreamException("Unable to read an RssElement. Reached the end of the stream.", e);
}
catch (XmlException e)
{
if (lineNumber != -1 || linePosition != -1)
{
if (reader.LineNumber == lineNumber && reader.LinePosition == linePosition)
{
throw exceptions.LastException;
}
}
lineNumber = reader.LineNumber;
linePosition = reader.LinePosition;
exceptions.Add(e); // just add to list of exceptions and continue :)
}
if (readData)
{
var readerName = reader.Name.ToLower();
switch (reader.NodeType)
{
case XmlNodeType.Element:
{
if (reader.IsEmptyElement)
{
break;
}
elementText = new StringBuilder();
switch (readerName)
{
case "item":
// is this the end of the channel element? (absence of </channel> before <item>)
if (!wroteChannel)
{
wroteChannel = true;
rssElement = channel; // return RssChannel
readData = false;
}
item = new RssItem(); // create new RssItem
channel.Items.Add(item);
break;
case "source":
source = new RssSource();
item.Source = source;
for (var i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i);
switch (reader.Name.ToLower())
{
case "url":
try
{
source.Url = new Uri(reader.Value);
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
}
}
break;
case "enclosure":
enclosure = new RssEnclosure();
item.Enclosure = enclosure;
for (var i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i);
switch (reader.Name.ToLower())
{
case "url":
try
{
enclosure.Url = new Uri(reader.Value);
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "length":
try
{
enclosure.Length = int.Parse(reader.Value);
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "type":
enclosure.Type = reader.Value;
break;
}
}
break;
case "guid":
guid = new RssGuid();
item.Guid = guid;
for (var i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i);
switch (reader.Name.ToLower())
{
case "ispermalink":
try
{
guid.PermaLink = bool.Parse(reader.Value);
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
}
}
break;
case "category":
category = new RssCategory();
if ((string)xmlNodeStack.Peek() == "channel")
{
channel.Categories.Add(category);
}
else
{
item.Categories.Add(category);
}
for (var i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i);
switch (reader.Name.ToLower())
{
case "url":
goto case "domain";
case "domain":
category.Domain = reader.Value;
break;
}
}
break;
case "channel":
channel = new RssChannel();
textInput = null;
image = null;
cloud = null;
source = null;
enclosure = null;
category = null;
item = null;
break;
case "image":
image = new RssImage();
channel.Image = image;
break;
case "textinput":
textInput = new RssTextInput();
channel.TextInput = textInput;
break;
case "cloud":
pushElement = false;
cloud = new RssCloud();
channel.Cloud = cloud;
for (var i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i);
switch (reader.Name.ToLower())
{
case "domain":
cloud.Domain = reader.Value;
break;
case "port":
try
{
cloud.Port = ushort.Parse(reader.Value);
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "path":
cloud.Path = reader.Value;
break;
case "registerprocedure":
cloud.RegisterProcedure = reader.Value;
break;
case "protocol":
switch (reader.Value.ToLower())
{
case "xml-rpc":
cloud.Protocol = RssCloudProtocol.XmlRpc;
break;
case "soap":
cloud.Protocol = RssCloudProtocol.Soap;
break;
case "http-post":
cloud.Protocol = RssCloudProtocol.HttpPost;
break;
default:
cloud.Protocol = RssCloudProtocol.Empty;
break;
}
break;
}
}
break;
case "rss":
for (var i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i);
if (reader.Name.ToLower() == "version")
{
switch (reader.Value)
{
case "0.91":
rssVersion = RssVersion.RSS091;
break;
case "0.92":
rssVersion = RssVersion.RSS092;
break;
case "2.0":
rssVersion = RssVersion.RSS20;
break;
default:
rssVersion = RssVersion.NotSupported;
break;
}
}
}
break;
case "rdf":
for (var i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i);
if (reader.Name.ToLower() == "version")
{
switch (reader.Value)
{
case "0.90":
rssVersion = RssVersion.RSS090;
break;
case "1.0":
rssVersion = RssVersion.RSS10;
break;
default:
rssVersion = RssVersion.NotSupported;
break;
}
}
}
break;
}
if (pushElement)
{
xmlNodeStack.Push(readerName);
}
break;
}
case XmlNodeType.EndElement:
{
if (xmlNodeStack.Count == 1)
{
break;
}
var childElementName = (string)xmlNodeStack.Pop();
var parentElementName = (string)xmlNodeStack.Peek();
switch (childElementName) // current element
{
// item classes
case "item":
rssElement = item;
readData = false;
break;
case "source":
source.Name = elementText.ToString();
rssElement = source;
readData = false;
break;
case "enclosure":
rssElement = enclosure;
readData = false;
break;
case "guid":
guid.Name = elementText.ToString();
rssElement = guid;
readData = false;
break;
case "category": // parent is either item or channel
category.Name = elementText.ToString();
rssElement = category;
readData = false;
break;
// channel classes
case "channel":
if (wroteChannel)
{
wroteChannel = false;
}
else
{
wroteChannel = true;
rssElement = channel;
readData = false;
}
break;
case "textinput":
rssElement = textInput;
readData = false;
break;
case "image":
rssElement = image;
readData = false;
break;
case "cloud":
rssElement = cloud;
readData = false;
break;
}
switch (parentElementName) // parent element
{
case "item":
switch (childElementName)
{
case "title":
item.Title = elementText.ToString();
break;
case "link":
item.Link = new Uri(elementText.ToString());
break;
case "description":
item.Description = elementText.ToString();
break;
case "author":
item.Author = elementText.ToString();
break;
case "comments":
item.Comments = elementText.ToString();
break;
case "pubdate":
try
{
item.PubDate = DateTime.Parse(elementText.ToString());
}
catch (Exception e)
{
try {
var tmp = elementText.ToString();
tmp = tmp.Substring(0, tmp.Length - 5);
tmp += "GMT";
item.PubDate = DateTime.Parse(tmp);
}
catch
{
exceptions.Add(e);
}
}
break;
}
break;
case "channel":
switch (childElementName)
{
case "title":
channel.Title = elementText.ToString();
break;
case "link":
try
{
channel.Link = new Uri(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "description":
channel.Description = elementText.ToString();
break;
case "language":
channel.Language = elementText.ToString();
break;
case "copyright":
channel.Copyright = elementText.ToString();
break;
case "managingeditor":
channel.ManagingEditor = elementText.ToString();
break;
case "webmaster":
channel.WebMaster = elementText.ToString();
break;
case "rating":
channel.Rating = elementText.ToString();
break;
case "pubdate":
try
{
channel.PubDate = DateTime.Parse(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "lastbuilddate":
try
{
channel.LastBuildDate = DateTime.Parse(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "generator":
channel.Generator = elementText.ToString();
break;
case "docs":
channel.Docs = elementText.ToString();
break;
case "ttl":
try
{
channel.TimeToLive = int.Parse(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
}
break;
case "image":
switch (childElementName)
{
case "url":
try
{
image.Url = new Uri(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "title":
image.Title = elementText.ToString();
break;
case "link":
try
{
image.Link = new Uri(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "description":
image.Description = elementText.ToString();
break;
case "width":
try
{
image.Width = Byte.Parse(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
case "height":
try
{
image.Height = Byte.Parse(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
}
break;
case "textinput":
switch (childElementName)
{
case "title":
textInput.Title = elementText.ToString();
break;
case "description":
textInput.Description = elementText.ToString();
break;
case "name":
textInput.Name = elementText.ToString();
break;
case "link":
try
{
textInput.Link = new Uri(elementText.ToString());
}
catch (Exception e)
{
exceptions.Add(e);
}
break;
}
break;
case "skipdays":
if (childElementName == "day")
{
switch (elementText.ToString().ToLower())
{
case "monday":
channel.SkipDays[0] = true;
break;
case "tuesday":
channel.SkipDays[1] = true;
break;
case "wednesday":
channel.SkipDays[2] = true;
break;
case "thursday":
channel.SkipDays[3] = true;
break;
case "friday":
channel.SkipDays[4] = true;
break;
case "saturday":
channel.SkipDays[5] = true;
break;
case "sunday":
channel.SkipDays[6] = true;
break;
}
}
break;
case "skiphours":
if (childElementName == "hour")
{
channel.SkipHours[Byte.Parse(elementText.ToString().ToLower())] = true;
}
break;
}
break;
}
case XmlNodeType.Text:
elementText.Append(reader.Value);
break;
case XmlNodeType.CDATA:
elementText.Append(reader.Value);
break;
}
}
}while (readData);
return(rssElement);
}
private static RssFeed read(string url, HttpWebRequest request, RssFeed oldFeed)
{
// ***** Marked for substantial improvement
var feed = new RssFeed();
RssElement element = null;
Stream stream = null;
var uri = new Uri(url);
feed.url = url;
switch (uri.Scheme)
{
case "file":
feed.lastModified = File.GetLastWriteTime(url);
if ((oldFeed != null) && (feed.LastModified == oldFeed.LastModified))
{
oldFeed.cached = true;
return(oldFeed);
}
stream = new FileStream(url, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
break;
case "https":
goto case "http";
case "http":
if (request == null)
{
request = (HttpWebRequest)WebRequest.Create(uri);
}
if (oldFeed != null)
{
request.IfModifiedSince = oldFeed.LastModified;
request.Headers.Add("If-None-Match", oldFeed.ETag);
}
try
{
var response = (HttpWebResponse)request.GetResponse();
feed.lastModified = response.LastModified;
feed.etag = response.Headers["ETag"];
try
{
if (response.ContentEncoding != "")
{
feed.encoding = Encoding.GetEncoding(response.ContentEncoding);
}
}
catch {}
stream = response.GetResponseStream();
}
catch (WebException we)
{
if (oldFeed != null)
{
oldFeed.cached = true;
return(oldFeed);
}
else
{
throw we; // bad
}
}
break;
}
if (stream != null)
{
RssReader reader = null;
try
{
reader = new RssReader(stream);
do
{
element = reader.Read();
if (element is RssChannel)
{
feed.Channels.Add((RssChannel)element);
}
}while (element != null);
feed.rssVersion = reader.Version;
}
finally
{
feed.exceptions = reader.Exceptions;
reader.Close();
}
}
else
{
throw new ApplicationException("Not a valid Url");
}
return(feed);
}