public ElementDescription GetElementDescriptionFromSiteUri(string siteUri)
{
try
{
var request = WebRequest.Create(siteUri);
request.Timeout = (int)Timeout.TotalMilliseconds;
var response = request.GetResponse();
var linksString = response.Headers["Link"];
var links = HttpWebLink.ParseLinks(linksString);
var link = links.FirstOrDefault(x => x.Relation == APIHttpHeaderRelation);
if (link == null)
{
return(null);
}
var uri = link.Uri;
var elementDescription = ElementDescription.ParseUri(uri);
return(elementDescription);
}
catch
{
return(null);
}
}
public static HttpWebLink ParseLink(string linkString)
{
var link = new HttpWebLink();
var leftAngledParenthesis = linkString.IndexOf('<');
var rightAngledParenthesis = linkString.IndexOf('>');
if (leftAngledParenthesis >= 0 && rightAngledParenthesis >= 0)
{
link.Uri = linkString.Substring(leftAngledParenthesis + 1, rightAngledParenthesis - leftAngledParenthesis - 1);
}
linkString = linkString.Substring(rightAngledParenthesis + 1);
var parameters = linkString.Split(new[] { "; " }, StringSplitOptions.RemoveEmptyEntries);
foreach (var parameter in parameters)
{
var splits = parameter.Split(new[] { '=' }, 2);
if (splits.Length == 2)
{
var parameterType = splits[0];
var parameterValue = splits[1].Trim('"');
switch (parameterType)
{
case "rel":
link.Relation = parameterValue;
break;
case "anchor":
link.Anchor = parameterValue;
break;
case "rev":
link.RelationTypes = parameterValue;
break;
case "hreflang":
link.Language = parameterValue;
break;
case "media":
link.Media = parameterValue;
break;
case "title":
link.Title = parameterValue;
break;
case "title*":
link.Titles = parameterValue;
break;
case "type":
link.Type = parameterValue;
break;
}
}
}
return link;
}
public static HttpWebLink ParseLink(string linkString)
{
var link = new HttpWebLink();
var leftAngledParenthesis = linkString.IndexOf('<');
var rightAngledParenthesis = linkString.IndexOf('>');
if (leftAngledParenthesis >= 0 && rightAngledParenthesis >= 0)
{
link.Uri = linkString.Substring(leftAngledParenthesis + 1, rightAngledParenthesis - leftAngledParenthesis - 1);
}
linkString = linkString.Substring(rightAngledParenthesis + 1);
var parameters = linkString.Split(new[] { "; " }, StringSplitOptions.RemoveEmptyEntries);
foreach (var parameter in parameters)
{
var splits = parameter.Split(new[] { '=' }, 2);
if (splits.Length == 2)
{
var parameterType = splits[0];
var parameterValue = splits[1].Trim('"');
switch (parameterType)
{
case "rel":
link.Relation = parameterValue;
break;
case "anchor":
link.Anchor = parameterValue;
break;
case "rev":
link.RelationTypes = parameterValue;
break;
case "hreflang":
link.Language = parameterValue;
break;
case "media":
link.Media = parameterValue;
break;
case "title":
link.Title = parameterValue;
break;
case "title*":
link.Titles = parameterValue;
break;
case "type":
link.Type = parameterValue;
break;
}
}
}
return(link);
}
