SharePoint REST API returns 404 for document library but is working for lists

Question

I am using C# HttpClient to query odata from Sharepoint. This works wonderfully if I am accessing a list.

I generate the SharePointOnlineCredentials to get authentication cookie and then I pass the full URL to this method:

HttpResponseMessage response = client.GetAsync(fullUrl).Result;

For lists, I always get the proper response back as json that I then parse out. For Document Libraries, this doesn't work... everything I read indicates that it should, but I always get a 404 response.

My actual Sharepoint api url looks like this:

https://<site>/<subsite>/_api/web/lists/getbytitle('<listName>')/items

If I run that URL in a chrome browser, it works for both lists and document libraries, but when I run that same exact URL in the C# HttpClient, it only works for lists... for some reason I get 404 for document library...

On a somewhat related note, I get "Bad Request" errors if I attempt to use any ODATA filters on a list or document library... but again, the filters work great in the browser... just not the C# HttpClient code...

Does anyone have ideas for what I can try? I'm at my wits end...

Answer 1

I found the answer... it comes down to a design decision by Microsoft and honestly it is rather stupid.

I was seeing 404 on the Document Library because the account I was using didn't have permissions for the Library. What confused me was the 404 response... normally if I don't have permissions I get a 403 "Forbidden" error... so I expected that a permissions issue would yield that same result for this Doc Library. I forgot I was using a different account for accessing the site than the one I was using in C# for testing.

So the answer comes down to this: Microsoft SharePoint hides sites if you don't have permissions to view them... so when you hit the URL in C# you get a 404 "Not Found" error... but when you hit them in a browser you get told you have to request permissions... that's extremely misleading... a 404 and 403 are NOT the same thing.

Answer 2

The following C# code for your reference.

static void Main(string[] args)
{
    //Creating Password
    string webUrl = "https://lz.sharepoint.com/sites/lz";
    string USER = "[email protected]";
    string PWD = "password";
    string listName = "Documents";
    string RESTURL = "{0}/_api/web/lists/getbytitle('{1}')/items";

    Task<string> result = getListItems(webUrl,listName,USER,PWD,RESTURL);
    result.Wait();

    Console.WriteLine(result.Result);
    Console.ReadLine();           
}
private static async Task<string> getListItems(string webUrl, string listName,string USER, string PWD,string RESTURL)
{  
    //Creating Credentials
    var passWord = new SecureString();
    foreach (var c in PWD) passWord.AppendChar(c);
    var credential = new SharePointOnlineCredentials(USER, passWord);

    //Creating Handler to allows the client to use credentials and cookie
    using (var handler = new HttpClientHandler() { Credentials = credential })
    {
        //Getting authentication cookies
        Uri uri = new Uri(webUrl);
        handler.CookieContainer.SetCookies(uri, credential.GetAuthenticationCookie(uri));

        //Invoking REST API
        using (var client = new HttpClient(handler))
        {
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

            HttpResponseMessage response = await client.GetAsync(string.Format(RESTURL, webUrl,listName)).ConfigureAwait(false);
            response.EnsureSuccessStatusCode();

            string jsonData = await response.Content.ReadAsStringAsync();

            return jsonData;
        }
    }
}