RssChannelDom DownloadChannelDom(string url)
{
// look for disk cache first
RssChannelDom dom = TryLoadFromDisk(url);
if (dom != null)
{
return(dom);
}
// download the feed
byte[] feed = new WebClient().DownloadData(url);
// parse it as XML
XmlDocument doc = new XmlDocument();
doc.Load(new MemoryStream(feed));
// parse into DOM
dom = RssXmlHelper.ParseChannelXml(doc);
// set expiry
string ttlString = null;
dom.Channel.TryGetValue("ttl", out ttlString);
int ttlMinutes = GetTtlFromString(ttlString, _defaultTtlMinutes);
DateTime utcExpiry = DateTime.UtcNow.AddMinutes(ttlMinutes);
dom.SetExpiry(utcExpiry);
// save to disk
TrySaveToDisk(doc, url, utcExpiry);
return(dom);
}
protected void LoadFromXml(XmlDocument doc)
{
// parse XML
RssChannelDom dom = RssXmlHelper.ParseChannelXml(doc);
// create the channel
LoadFromDom(dom);
}
internal XmlDocument SaveAsXml()
{
XmlDocument doc = RssXmlHelper.CreateEmptyRssXml();
XmlNode channelNode = RssXmlHelper.SaveRssElementAsXml(doc.DocumentElement, this, "channel");
if (_image != null)
{
RssXmlHelper.SaveRssElementAsXml(channelNode, _image, "image");
}
foreach (RssItemType item in _items)
{
RssXmlHelper.SaveRssElementAsXml(channelNode, item, "item");
}
return(doc);
}
public static void Main(string[] args)
{
Console.WriteLine("Simple RSS Compiler v2.0");
Console.WriteLine();
// Process command line
if (args.Length != 2)
{
Console.WriteLine("usage: rssdl.exe url-or-file outputcode.cs");
return;
}
string url = args[0];
string codeFilename = args[1];
string classNamePrefix = Path.GetFileNameWithoutExtension(codeFilename);
// Load the channel data from supplied url
string codeString;
try
{
using (Stream feedStream = DownloadManager.GetFeed(url))
{
using (XmlTextReader reader = new XmlTextReader(feedStream))
{
codeString = RssXmlHelper.ConvertToRssXml(reader);
try
{
// Open the output code file
using (TextWriter codeWriter = new StreamWriter(codeFilename, false))
{
// Get the language from file extension
string lang = Path.GetExtension(codeFilename);
if (lang != null && lang.Length > 1 && lang.StartsWith("."))
{
lang = lang.Substring(1).ToUpperInvariant();
}
else
{
lang = "CS";
}
// Generate source
try
{
RssCodeGenerator.GenerateCode(codeString, url, lang, string.Empty, classNamePrefix, codeWriter, true);
Console.WriteLine("Done -- generated '{0}'.", codeFilename);
return;
}
catch (Exception e)
{
Console.WriteLine("*** Error generating '{0}' *** {1}: {2}", codeFilename, e.GetType().Name, e.Message);
}
}
File.Delete(codeFilename);
}
catch (Exception e)
{
Console.WriteLine("*** Failed to open '{0}' for writing *** {1}: {2}", codeFilename, e.GetType().Name, e.Message);
}
}
}
}
catch (Exception e)
{
Console.WriteLine("*** Failed to load '{0}' *** {1}: {2}", url, e.GetType().Name, e.Message);
}
}
RssChannelDom TryLoadFromDisk(string url)
{
if (_directoryOnDisk == null)
{
return(null); // no place to cache
}
// look for all files matching the prefix
// looking for the one matching url that is not expired
// removing expired (or invalid) ones
string pattern = GetTempFileNamePrefixFromUrl(url) + "_*.rss";
string[] files = Directory.GetFiles(_directoryOnDisk, pattern, SearchOption.TopDirectoryOnly);
foreach (string rssFilename in files)
{
XmlDocument rssDoc = null;
bool isRssFileValid = false;
DateTime utcExpiryFromRssFile = DateTime.MinValue;
string urlFromRssFile = null;
try {
rssDoc = new XmlDocument();
rssDoc.Load(rssFilename);
// look for special XML comment (before the root tag)'
// containing expiration and url
XmlComment comment = rssDoc.DocumentElement.PreviousSibling as XmlComment;
if (comment != null)
{
string c = comment.Value;
int i = c.IndexOf('@');
long expiry;
if (long.TryParse(c.Substring(0, i), out expiry))
{
utcExpiryFromRssFile = DateTime.FromBinary(expiry);
urlFromRssFile = c.Substring(i + 1);
isRssFileValid = true;
}
}
}
catch {
// error processing one file shouldn't stop processing other files
}
// remove invalid or expired file
if (!isRssFileValid || utcExpiryFromRssFile < DateTime.UtcNow)
{
try {
File.Delete(rssFilename);
}
catch {
}
// try next file
continue;
}
// match url
if (urlFromRssFile == url)
{
// found a good one - create DOM and set expiry (as found on disk)
RssChannelDom dom = RssXmlHelper.ParseChannelXml(rssDoc);
dom.SetExpiry(utcExpiryFromRssFile);
return(dom);
}
}
// not found
return(null);
}
