Get List Name from full url - file

Question

I have hundreds of different random URLs coming in, all documents in libs, without any other parameters from different farms and different site collections and sites, goal is to download a file as a binary array from SharePoint.
So e.g. incoming url = http://a.b.c.d.e/f.g/h.i/j/k/l/m.docx .
So how to get the (a) correct site collection root url (b) site root url (c) library root url from this? The only way I now think of is slowly stripping off each part of the url until e.g. .Rootfolder no longer gives an exception... or the other way around slowly adding bits by the first part of the url until rootfolder nog longers gives an exception then query for subwebs etc..

Answer 1

The point is that ClientContext constructor accepts the url of web/site only.
But if the url will be specified in the following format:
http://site/web/documents/file.docx
then the exception System.Net.WebException will occur.
The following example demonstrates how to resolve ClientContext from request Url:
public static class ClientContextUtilities
{
/// <summary>
/// Resolve client context
/// </summary>
/// <param name="requestUri"></param>
/// <param name="context"></param>
/// <param name="credentials"></param>
/// <returns></returns>
public static bool TryResolveClientContext(Uri requestUri, out ClientContext context, ICredentials credentials)
{
context = null;
var baseUrl = requestUri.GetLeftPart(UriPartial.Authority);
for (int i = requestUri.Segments.Length; i >= 0; i--)
{
var path = string.Join(string.Empty, requestUri.Segments.Take(i));
string url = string.Format("{0}{1}", baseUrl, path);
try
{
context = new ClientContext(url);
if (credentials != null)
context.Credentials = credentials;
context.ExecuteQuery();
return true;
}
catch (Exception ex) {}
}
return false;
}
}
Usage
ClientContext context;
if (ClientContextUtilities.TryResolveClientContext(requestUri, out context, null))
{
using (context)
{
var baseUrl = requestUri.GetLeftPart(UriPartial.Authority);
var fileServerRelativeUrl = requestUri.ToString().Replace(baseUrl, string.Empty);
var file = context.Web.GetFileByServerRelativeUrl(fileServerRelativeUrl);
context.Load(file);
context.Load(context.Web);
context.Load(context.Site);
context.ExecuteQuery();
}
}
Since your goal is to download a file, there is pretty straightforward way to accomplish it without parsing url parts.
For example, using WebClient.DownloadFile Method:
private static void DownloadFile(Uri fileUri, ICredentials credentials, string localFileName)
{
using(var client = new WebClient())
{
client.Credentials = credentials;
client.DownloadFile(fileUri, localFileName);
}
}

Answer 2

I have made a working method but it seems elaborate, so any suggestions for improvement are welcome just to "download file if one of the specific columns has value "yes":
public void getDocument(Document doc)
{
// get the filename
Uri uri = new Uri(doc.uri);
doc.filename = "";
doc.filename = System.IO.Path.GetFileName(uri.LocalPath);
//string fullPathWithoutFileName = docUri.Replace(filename, "");
// would also include ?a&b so:
string[] splitDocUri = doc.uri.Split('/');
string fullPathWithoutFileName = "";
for (int i = 0; i < splitDocUri.Length -1; i++)
{
fullPathWithoutFileName += (splitDocUri[i] + '/');
}
// get via "_api/contextinfo" the context info
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(fullPathWithoutFileName + "_api/contextinfo");
req.Method = "POST";
req.Accept = "application/json; odata=verbose";
req.Credentials = new NetworkCredential(doc.username, doc.password, doc.domain);
req.Headers.Add("X-FORMS_BASED_AUTH_ACCEPTED","f");
req.ContentLength = 0;
BypassCertificateError();
HttpWebResponse rp = (HttpWebResponse)req.GetResponse();
Stream postStream = rp.GetResponseStream();
StreamReader postReader = new StreamReader(postStream);
string results = postReader.ReadToEnd();
// Now parse out some values needs system.web.extensions
JavaScriptSerializer jss = new JavaScriptSerializer();
var d = jss.Deserialize<dynamic>(results);
string formDigestValue = d["d"]["GetContextWebInformation"]["FormDigestValue"];
// the full url to the website e.g. "http://server:7777/level1/level 2"
string webFullUrl = d["d"]["GetContextWebInformation"]["WebFullUrl"];
// the full url to the site collection e.g. "http://server:7777"
string siteFullUrl = d["d"]["GetContextWebInformation"]["SiteFullUrl"];
// now we can create a context
ClientContext ctx = new ClientContext(webFullUrl);
ctx.ExecutingWebRequest +=
new EventHandler<WebRequestEventArgs>(ctx_MixedAuthRequest);
BypassCertificateError();
ctx.AuthenticationMode = ClientAuthenticationMode.Default;
ctx.Credentials = new NetworkCredential(doc.username, doc.password, doc.domain);
// Get the List
Microsoft.SharePoint.Client.File file = ctx.Web.GetFileByServerRelativeUrl(uri.AbsolutePath);
List list = file.ListItemAllFields.ParentList;
ctx.Load(list);
ctx.ExecuteQuery();
// execute a CAML query against it
CamlQuery camlQuery = new CamlQuery();
camlQuery.ViewXml =
"<View><Query><Where><Eq><FieldRef Name='FileLeafRef'/>" +
"<Value Type='Text'>" + doc.filename + "</Value></Eq></Where>" +
"<RowLimit>1</RowLimit></Query></View>";
ListItemCollection listItems = list.GetItems(camlQuery);
ctx.Load(listItems);
try {
ctx.ExecuteQuery();
}
catch
{
// e.g. : no access or the listname as incorrectly deduced
throw;
}
// and now retrieve the items needed
if (listItems.Count == 1)
{
ListItem item = listItems[0];
// some more checking from testColumn to decide if to download yes/no
string testColumn;
if (item.IsPropertyAvailable("testColumn")) {
testColumn = (string)item["testColumn"];
}
FileInformation fileInformation =
Microsoft.SharePoint.Client.File.OpenBinaryDirect(ctx,
(string)item["FileRef"]);
doc.bytes = ReadFully(fileInformation.Stream);
}
else
{
doc.errormessage = "Error: No document found";
}
}