(MFC) OneDrive -- List Large Directory

Demonstrates how to get the entire collection of DriveItem children when the collection is large and multiple pages need to be requested. To test this example, I created a DriveItem with 450 children.

Note: This example requires Chilkat v9.5.0.68 or greater.

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

See Also: Using MFC CString in Chilkat

#include <CkHttp.h>
#include <CkJsonObject.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    CkHttp http;

    // Use your previously obtained access token here:
    // See the following examples for getting an access token:
    //    Get Microsoft Graph OAuth2 Access Token (Azure AD v2.0 Endpoint).
    //    Get Microsoft Graph OAuth2 Access Token (Azure AD Endpoint).
    //    Refresh Access Token (Azure AD v2.0 Endpoint).
    //    Refresh Access Token (Azure AD Endpoint).

    // (Make sure your token was obtained with the FilesRead or Files.ReadWrite scope.)
    http.put_AuthToken("MICROSOFT_GRAPH_ACCESS_TOKEN");

    // This example will get the DriveItems in /lots-of-files, which has 450 children..
    http.SetUrlVar("item_path","/lots-of-files");

    const char *resp = 0;
    int i;
    int numItems;

    CkJsonObject json;
    json.put_EmitCompact(false);

    // This loop will download DriveItems in sets of 50 until no more exist.
    bool bGetMore = true;
    // (Add the $top query parameter to define the page size, i.e. the max number of results to return).
    const char *nextLink = "https://graph.microsoft.com/v1.0/me/drive/root:{$item_path}:/children?$top=50";

    while ((bGetMore == true)) {

        // Get the next chunk of DriveItems
        resp = http.quickGetStr(nextLink);
        if (http.get_LastMethodSuccess() != true) {
            strOut.append(http.lastErrorText());
            strOut.append("\r\n");
            SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
            return;
        }

        // The response should be JSON.
        json.Load(resp);

        // A successful response should return a status code of 200.
        if (http.get_LastStatus() != 200) {
            strOut.append(json.emit());
            strOut.append("\r\n");
            strOut.append("Response status = ");
            strOut.appendInt(http.get_LastStatus());
            strOut.append("\r\n");
            SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
            return;
        }

        // Iterate over the DriveItems in the JSON response:
        i = 0;
        numItems = json.SizeOfArray("value");
        while (i < numItems) {
            json.put_I(i);
            strOut.append("name: ");
            strOut.append(json.stringOf("value[i].name"));
            strOut.append("\r\n");
            i = i + 1;
        }

        // If a nextLink was included in the JSON, use it to get the next set of 50 DriveItems.
        // Otherwise, exit the loop.
        if (json.HasMember("\"@odata.nextLink\"") == true) {
            nextLink = json.stringOf("\"@odata.nextLink\"");
            strOut.append("nextLink: ");
            strOut.append(nextLink);
            strOut.append("\r\n");
        }
        else {
            bGetMore = false;
        }

    }



    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }