(.NET Core C#) SharePoint -- Download Newer Files

See more SharePoint Examples

Demonstrates how to download all files from a SharePoint folder that are newer than the local files.

Chilkat .NET Downloads Chilkat .NET Assemblies Chilkat for .NET Core Chilkat for Mono

// This requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// -------------------------------------------------------------------------
// The following comments apply to SharePoint Windows classic authentication.
// -------------------------------------------------------------------------
// For example, imagine our SharePoint endpoint is https://xyzoffice.mycompany.com/
// The SHAREPOINT_NTLM_DOMAIN would be "mycompany.com"
// The SHAREPOINT_HTTPS_DOMAIN would be "xyzoffice.mycompany.com"
// Also, the SHAREPOINT_USERNAME would be just the name, not a full email address.
// for example, "chilkat" instead of "chilkat@mycompany.com"

Chilkat.Http http = new Chilkat.Http();

// If SharePoint Windows classic authentication is used, then set the 
// Login, Password, LoginDomain, and NtlmAuth properties.
http.Login = "SHAREPOINT_USERNAME";
http.Password = "SHAREPOINT_PASSWORD";
http.LoginDomain = "SHAREPOINT_NTLM_DOMAIN";
http.NtlmAuth = true;

// -------------------------------------------------------------------------
// The more common case is to use SharePoint Online authentication (via the SPOIDCRL cookie).
// If so, do not set Login, Password, LoginDomain, and NtlmAuth, and instead
// establish the cookie as shown at SharePoint Online Authentication
// -------------------------------------------------------------------------

// First we'll download a list of all the files in the /Documents folder.
// This provides the names and last-modified date/times of the files located
// on the SharePoint server.
http.Accept = "application/json;odata=verbose";
http.AcceptCharset = "utf-8";

Chilkat.StringBuilder sbJson = new Chilkat.StringBuilder();
bool success = http.QuickGetSb("https://SHAREPOINT_HTTPS_DOMAIN/_api/web/GetFolderByServerRelativeUrl('/Documents')/Files",sbJson);
if (success != true) {
    Debug.WriteLine(http.LastErrorText);
    return;
}

// Before proceeding, make sure the local directory where we'll be downloading files exists.
Chilkat.FileAccess fac = new Chilkat.FileAccess();
fac.DirEnsureExists("qa_output/sharepoint/Documents");

// OK.. load the JSON and iterate over each file
Chilkat.JsonObject json = new Chilkat.JsonObject();
json.LoadSb(sbJson);

int numFiles = json.SizeOfArray("d.results");
Debug.WriteLine("Number of Files in the SharePoint /Documents folder = " + Convert.ToString(numFiles));

Chilkat.CkDateTime lastModRemote = new Chilkat.CkDateTime();
Chilkat.CkDateTime lastModLocal = null;

Chilkat.StringBuilder localPath = new Chilkat.StringBuilder();
Chilkat.StringBuilder fileUrl = new Chilkat.StringBuilder();

int i = 0;
while (i < numFiles) {
    json.I = i;

    string filename = json.StringOf("d.results[i].Name");
    string sLastModified = json.StringOf("d.results[i].TimeLastModified");

    Debug.WriteLine(Convert.ToString(i + 1) + ": " + filename + " (" + sLastModified + ")");

    lastModRemote.SetFromTimestamp(sLastModified);

    bool bDownload = false;
    // Check to see if the local file exists.  If not, then download.
    localPath.SetString("qa_output/sharepoint/Documents/");
    localPath.Append(filename);
    if (fac.FileExists(localPath.GetAsString()) != true) {
        Debug.WriteLine("This file does not exist locally.");
        bDownload = true;
    }
    else {
        // Get the local file's date time and compare with the remote file date/time.
        lastModLocal = fac.GetLastModified(localPath.GetAsString());
        if (fac.LastMethodSuccess == true) {
            // Get the difference in seconds between the local and remote last-modified times.
            // if the return value is negative, then the caller's time is 
            // older than the argument.  (in this case, a negative return value means
            // the local file is older than the remote file.

            // Note: The DiffSeconds method was found to be missing in the Chilkat .NET build
            // (and possibly in other builds). It will be present in the v9.5.0.67 release and later.
            int numSeconds = lastModLocal.DiffSeconds(lastModRemote);
            if (numSeconds < 0) {
                Debug.WriteLine("The local file is older than the remote file.");
                bDownload = true;
            }

        }
        else {
            Debug.WriteLine("Unable to get the local file's last-modified date/time.");
            Debug.WriteLine(fac.LastErrorText);
        }

    }

    if (bDownload == true) {
        fileUrl.SetString("https://SHAREPOINT_HTTPS_DOMAIN/_api/web/GetFolderByServerRelativeUrl('/Documents')/Files('");
        fileUrl.Append(filename);
        fileUrl.Append("')/$value");

        Debug.WriteLine("Downloading " + filename);

        success = http.Download(fileUrl.GetAsString(),localPath.GetAsString());
        if (success != true) {
            Debug.WriteLine(http.LastErrorText);
            return;
        }

        // Set the local file's last-modified date/time to that of the server's.
        fac.SetLastModified(localPath.GetAsString(),lastModRemote);

    }

    i = i + 1;
}

Debug.WriteLine("All finished.");