Get the Top Level Site URL (when given a subsite URL)

Question

I have been using this code to retrieve the URL of the top level site;

string result = String.Empty;
using (var service = GetSitesWebService())
{
    result = service.GetSite(mySubSiteURL);
}

if (!String.IsNullOrWhiteSpace(result))
{
    var doc = XDocument.Parse(result);
    rootUrl = (string)doc.Element("Site").Attribute("Url");
}

This works fine if the user has certain permissions (not sure what they are), but if the user only has "Contributor" access then the above call to GetSite fails with a 401 - Unauthorized.

Is there any alternative approach to getting the top-level site URL, given some arbitrary site URL? I would strongly prefer to be able to do this via the Web Services, but the Client Object Model might have to do if web services don't support this for low-privilege users.

Answer 1

So if you are inside of Sharepoint Context (web part, timer job, web service etc..) then simply use:

var topLevelSiteURL = Microsoft.SharePoint.SPContext.Current.Site.Url

Answer 2

excuse me for response with a question. But, how do you to connect to web services? You need the url to connect to WS, and then you have a url. In that case you can instantiate a SPSite class with the url. Yes you can get the site collection from any subsite. url = "server/sitecollection1/subsite1"

using(SPSite site = new SPSite(url))
{
  SPWeb web = site.RootWeb;  
}

In your sample, the users have acces to Site Collection?

Remember that you can to elevate privileges with

SPSecurity.RunWithElevatedPrivileges

Answer 3

The client app it's web? in this case http://antoniolanaro.blogspot.com/2011/03/ecmascript-get-site-collection-server.html