(MFC) SharePoint -- Download Newer Files

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

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkHttp.h>
#include <CkStringBuilder.h>
#include <CkFileAccess.h>
#include <CkJsonObject.h>
#include <CkDateTime.h>

void ChilkatSample(void)
    {
    CkString strOut;

    //  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"

    CkHttp http;

    //  If SharePoint Windows classic authentication is used, then set the
    //  Login, Password, LoginDomain, and NtlmAuth properties.
    http.put_Login("SHAREPOINT_USERNAME");
    http.put_Password("SHAREPOINT_PASSWORD");
    http.put_LoginDomain("SHAREPOINT_NTLM_DOMAIN");
    http.put_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.put_Accept("application/json;odata=verbose");

    CkStringBuilder sbJson;
    bool success = http.QuickGetSb("https://SHAREPOINT_HTTPS_DOMAIN/_api/web/GetFolderByServerRelativeUrl('/Documents')/Files",sbJson);
    if (success != true) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

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

    //  OK.. load the JSON and iterate over each file
    CkJsonObject json;
    json.LoadSb(sbJson);

    int numFiles = json.SizeOfArray("d.results");
    strOut.append("Number of Files in the SharePoint /Documents folder = ");
    strOut.appendInt(numFiles);
    strOut.append("\r\n");

    CkDateTime lastModRemote;
    CkDateTime *lastModLocal = 0;

    CkStringBuilder localPath;
    CkStringBuilder fileUrl;

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

        const char *filename = json.stringOf("d.results[i].Name");
        const char *sLastModified = json.stringOf("d.results[i].TimeLastModified");

        strOut.appendInt(i + 1);
        strOut.append(": ");
        strOut.append(filename);
        strOut.append(" (");
        strOut.append(sLastModified);
        strOut.append(")");
        strOut.append("\r\n");

        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) {
            strOut.append("This file does not exist locally.");
            strOut.append("\r\n");
            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.get_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) {
                    strOut.append("The local file is older than the remote file.");
                    strOut.append("\r\n");
                    bDownload = true;
                }

                delete lastModLocal;
            }
            else {
                strOut.append("Unable to get the local file's last-modified date/time.");
                strOut.append("\r\n");
                strOut.append(fac.lastErrorText());
                strOut.append("\r\n");
            }

        }

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

            strOut.append("Downloading ");
            strOut.append(filename);
            strOut.append("\r\n");

            success = http.Download(fileUrl.getAsString(),localPath.getAsString());
            if (success != true) {
                strOut.append(http.lastErrorText());
                strOut.append("\r\n");
                SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
                return;
            }

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

        }

        i = i + 1;
    }

    strOut.append("All finished.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }