/// <summary> Check if a resource is a valid URL.
/// </summary>
/// <param name="resourceLocn">The resource to test.
/// </param>
/// <returns> <code>true</code> if the resource is a valid URL.
///
/// </returns>
public static bool IsURL(string resourceLocn)
{
System.Uri url;
bool ret;
try
{
url = SupportClass.CreateUri(resourceLocn);
ret = true;
}
catch (System.UriFormatException)
{
ret = false;
}
return(ret);
}
public virtual System.Uri ConstructUrl(string link, string baseURL)
{
string path;
bool modified;
bool absolute;
int index;
System.Uri url; // constructed URL combining relative link and base
url = new System.Uri(SupportClass.CreateUri(baseURL), link);
path = url.AbsolutePath;
modified = false;
absolute = link.StartsWith("/");
if (!absolute)
{
// we prefer to fix incorrect relative links
// this doesn't fix them all, just the ones at the start
while (path.StartsWith("/."))
{
if (path.StartsWith("/../"))
{
path = path.Substring(3);
modified = true;
}
else if (path.StartsWith("/./") || path.StartsWith("/."))
{
path = path.Substring(2);
modified = true;
}
else
{
break;
}
}
}
// fix backslashes
while (-1 != (index = path.IndexOf("/\\")))
{
path = path.Substring(0, (index + 1) - (0)) + path.Substring(index + 2);
modified = true;
}
if (modified)
{
url = SupportClass.CreateUri(url, path);
}
return(url);
}
/// <summary> Opens a connection based on a given string.
/// The string is either a file, in which case <code>file://localhost</code>
/// is prepended to a canonical path derived from the string, or a url that
/// begins with one of the known protocol strings, i.e. <code>http://</code>.
/// Embedded spaces are silently converted to %20 sequences.
/// </summary>
/// <param name="resource">The name of a file or a url.
/// </param>
/// <param name="feedback">The object to use for messages or <code>null</code> for no feedback.
/// </param>
/// <exception cref=""> ParserException if the string is not a valid url or file.
///
/// </exception>
public static WebRequest OpenConnection(string resource, ParserFeedback feedback)
{
System.Uri url;
WebRequest ret;
try
{
url = SupportClass.CreateUri(LinkProcessor.FixSpaces(resource));
ret = ParserHelper.OpenConnection(url, feedback);
}
catch (System.UriFormatException ufe)
{
string msg = "HTMLParser.OpenConnection() : Error in opening a connection to " + resource;
ParserException ex = new ParserException(msg, ufe);
if (null != feedback)
{
feedback.Error(msg, ex);
}
throw ex;
}
return(ret);
}
public int FindImageTagCount()
{
int imgTagCount = 0;
try
{
System.Uri url = SupportClass.CreateUri(UriToExamine);
System.IO.Stream responseStream = System.Net.WebRequest.Create(url).GetResponse().GetResponseStream();
System.IO.StreamReader reader;
reader = new System.IO.StreamReader(responseStream, System.Text.Encoding.UTF7);
imgTagCount = CountImageTagsWithoutHTMLParser(reader);
responseStream.Close();
}
catch (System.UriFormatException)
{
System.Console.Error.WriteLine("URL was malformed!");
}
catch (System.IO.IOException)
{
System.Console.Error.WriteLine("IO Exception occurred while trying to open stream");
}
return(imgTagCount);
}
