(Delphi DLL) OneDrive -- Upload Large Files with an Upload Session

See more OneDrive Examples

Demonstrates how to upload large files with an upload session. See OneDrive Upload Session for more general information.

Note: This example requires Chilkat v9.5.0.97 or greater.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Url, HttpRequest, HttpResponse, FileAccess, JsonObject, StringBuilder, Http;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
json: HCkJsonObject;
http: HCkHttp;
url: PWideChar;
resp: HCkHttpResponse;
jsonSession: HCkJsonObject;
fragSize: Integer;
localFilePath: PWideChar;
fac: HCkFileAccess;
fileSize: Integer;
numFragments: Integer;
i: Integer;
uploadUrl: HCkUrl;
req: HCkHttpRequest;
sbOffset: HCkStringBuilder;
sbNumBytes: HCkStringBuilder;
sbRange: HCkStringBuilder;
bytesRemaining: Integer;
chunkSize: Integer;
expectedStatusCode: Integer;
numReplaced: Integer;

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

// This example uses the OAuth client credentials flow.
// See How to Create an Azure App Registration for OAuth 2.0 Client Credentials

// Use your client ID, client secret, and tenant ID in the following lines
json := CkJsonObject_Create();
CkJsonObject_UpdateString(json,'client_id','2871da2c-8176-4b7f-869b-2311aa82e743');
CkJsonObject_UpdateString(json,'client_secret','2hu9Q~r5QuryUcEkNbg1btLtnfU1VUXzhSCG6brH');
CkJsonObject_UpdateString(json,'scope','https://graph.microsoft.com/.default');
CkJsonObject_UpdateString(json,'token_endpoint','https://login.microsoftonline.com/114d7ed6-71bf-4dbe-a866-748364121bf2/oauth2/v2.0/token');

http := CkHttp_Create();
CkHttp_putAuthToken(http,CkJsonObject__emit(json));

// ----------------------------------------------------------------------------
// Step 1: Create an upload session

// To begin a large file upload, your app must first request a new upload session. This creates a 
// temporary storage location where the bytes of the file will be saved until the complete file is uploaded. 
// Once the last byte of the file has been uploaded the upload session is completed and the final file is shown 
// in the destination folder.

// Send the following POST to create an upload session:
// If not using "me", then the path should be /v1.0/users/{id | userPrincipalName}/...
// POST /v1.0/users/{user_id}/drive/root:/{path_to_item}:/createUploadSession

CkHttp_SetUrlVar(http,'path_to_item','/somefolder/big.zip');
CkHttp_SetUrlVar(http,'user_id','4fe732c3-322e-4a6b-b729-2fd1eb5c6104');
url := 'https://graph.microsoft.com/v1.0/users/{$user_id}/drive/root:/{$path_to_item}:/createUploadSession';
resp := CkHttp_PostJson2(http,url,'application/json','{}');
if (CkHttp_getLastMethodSuccess(http) <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

// If successful, a 200 status code is returned, with the session details (in JSON format).
jsonSession := CkJsonObject_Create();
CkJsonObject_putEmitCompact(jsonSession,False);
CkJsonObject_Load(jsonSession,CkHttpResponse__bodyStr(resp));

if (CkHttpResponse_getStatusCode(resp) <> 200) then
  begin

    Memo1.Lines.Add(CkJsonObject__emit(jsonSession));
    Memo1.Lines.Add('Response status = ' + IntToStr(CkHttpResponse_getStatusCode(resp)));
    CkHttpResponse_Dispose(resp);
    Exit;
  end;

CkHttpResponse_Dispose(resp);

Memo1.Lines.Add(CkJsonObject__emit(jsonSession));

// A sample response:

// 	{
// 	  "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#microsoft.graph.uploadSession",
// 	  "uploadUrl": "https://api.onedrive.com/rup/3a33fceb9b74cc15/eyJSZXNvdXJjZUlEI ... 65yDYUiS3JTDnnhqCHxw",
// 	  "expirationDateTime": "2017-06-11T12:40:23.239Z",
// 	  "nextExpectedRanges": [
// 	    "0-"
// 	  ]
// 	}
// 

// ----------------------------------------------------------------------------
// Step 2: Upload Data in Segments (a.k.a. Fragments or Chunks)

// Microsoft states this requirement: Use a fragment size that is a multiple of 320 KiB (320 * 1024 bytes). 
// Failing to use a fragment size that is a multiple of 320 KiB can result in large file transfers failing after the 
// last fragment is uploaded.  (Note: This is a detail imposed by Microsoft's OneDrive server-side implementation.)

fragSize := 320 * 1024;
localFilePath := 'qa_data/zips/big.zip';

// Upload the file big.zip in 320KiB segments.
// Note: The FileSize method returns a signed 32-bit integer.  If the file is potentially larger than 2GB, call FileSizeStr instead to return
// the size of the file as a string, then convert to an integer value.
fac := CkFileAccess_Create();
fileSize := CkFileAccess_FileSize(fac,localFilePath);

// Open the file to get the number of fragments.
success := CkFileAccess_OpenForRead(fac,localFilePath);
if (success = False) then
  begin
    Memo1.Lines.Add(CkFileAccess__lastErrorText(fac));
    Exit;
  end;
numFragments := CkFileAccess_GetNumBlocks(fac,fragSize);
CkFileAccess_FileClose(fac);

i := 0;

Memo1.Lines.Add('fileSize = ' + IntToStr(fileSize));
Memo1.Lines.Add('numFragments = ' + IntToStr(numFragments));

uploadUrl := CkUrl_Create();
CkUrl_ParseUrl(uploadUrl,CkJsonObject__stringOf(jsonSession,'uploadUrl'));

CkJsonObject_putEmitCompact(json,False);

req := CkHttpRequest_Create();
CkHttpRequest_putHttpVerb(req,'PUT');
CkHttpRequest_putPath(req,CkUrl__pathWithQueryParams(uploadUrl));
CkHttpRequest_putContentType(req,'application/octet-stream');

sbOffset := CkStringBuilder_Create();
sbNumBytes := CkStringBuilder_Create();
sbRange := CkStringBuilder_Create();

// IMPORTANT: The uploadUrl is a temporary URL to be used to upload the fragment.
// It requires no authentication (because the URL itself could only have been obtained from an authenticated
// request to start the upload session).  Therefore, do not allow the upload URL to be publicly seen,
// otherwise anybody could upload to your OneDrive.
CkHttp_putAuthToken(http,'');

bytesRemaining := fileSize;
while i < numFragments do
  begin

    // The success response code for intermediate chunks is 202,
    // whereas the final chunk will have a 201 success response where
    // the response body is the JSON DriveItem.
    chunkSize := fragSize;
    expectedStatusCode := 202;
    if (bytesRemaining < chunkSize) then
      begin
        chunkSize := bytesRemaining;
        expectedStatusCode := 201;
      end;
    Memo1.Lines.Add('  this chunkSize = ' + IntToStr(chunkSize));

    // Indicate the fragment in the local file to be streamed in the upload.
    CkStringBuilder_Clear(sbOffset);
    CkStringBuilder_AppendInt(sbOffset,i * fragSize);
    CkStringBuilder_Clear(sbNumBytes);
    CkStringBuilder_AppendInt(sbNumBytes,chunkSize);
    CkHttpRequest_StreamChunkFromFile(req,localFilePath,CkStringBuilder__getAsString(sbOffset),CkStringBuilder__getAsString(sbNumBytes));

    // The Content-Range header field must be set for this fragment.  For example:
    // Content-Range: bytes 0-25/128
    CkStringBuilder_SetString(sbRange,'bytes start-end/fileSize');
    numReplaced := CkStringBuilder_ReplaceI(sbRange,'start',i * fragSize);
    numReplaced := CkStringBuilder_ReplaceI(sbRange,'end',i * fragSize + chunkSize - 1);
    numReplaced := CkStringBuilder_ReplaceI(sbRange,'fileSize',fileSize);
    CkHttpRequest_AddHeader(req,'Content-Range',CkStringBuilder__getAsString(sbRange));
    Memo1.Lines.Add('  this content-range: ' + CkStringBuilder__getAsString(sbRange));

    resp := CkHttp_SynchronousRequest(http,CkUrl__host(uploadUrl),443,True,req);
    if (CkHttp_getLastMethodSuccess(http) <> True) then
      begin
        Memo1.Lines.Add(CkHttp__lastErrorText(http));
        Exit;
      end;

    CkJsonObject_Load(json,CkHttpResponse__bodyStr(resp));
    // A 202 response status code indicates success.
    if (CkHttpResponse_getStatusCode(resp) <> expectedStatusCode) then
      begin

        Memo1.Lines.Add(CkJsonObject__emit(json));
        Memo1.Lines.Add('Response status = ' + IntToStr(CkHttpResponse_getStatusCode(resp)));
        CkHttpResponse_Dispose(resp);
        Exit;
      end;
    CkHttpResponse_Dispose(resp);
    Memo1.Lines.Add(CkJsonObject__emit(json));
    Memo1.Lines.Add('---- Chunk ' + IntToStr(i) + ' uploaded ----');

    bytesRemaining := bytesRemaining - chunkSize;
    i := i + 1;
  end;

Memo1.Lines.Add('data uploaded.');

// ----------------------------------------------------------------------------
// Sample output for the above session:

// {
//   "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#microsoft.graph.uploadSession",
//   "uploadUrl": "https://api.onedrive.com/rup/3a33fceb9b74cc15/eyJSZXNvd ... QoKK2iuh1A",
//   "expirationDateTime": "2017-06-11T14:04:45.438Z",
//   "nextExpectedRanges": [
//     "0-"
//   ]
// }
// 
// fileSize = 1366807
// numFragments = 5
//   this chunkSize = 327680
//   this content-range: bytes 0-327679/1366807
// {
//   "expirationDateTime": "2017-06-11T14:04:45.438Z",
//   "nextExpectedRanges": [
//     "327680-1366806"
//   ]
// }
// 
// ---- Chunk 0 uploaded ----
//   this chunkSize = 327680
//   this content-range: bytes 327680-655359/1366807
// {
//   "expirationDateTime": "2017-06-11T14:04:45.438Z",
//   "nextExpectedRanges": [
//     "655360-1366806"
//   ]
// }
// 
// ---- Chunk 1 uploaded ----
//   this chunkSize = 327680
//   this content-range: bytes 655360-983039/1366807
// {
//   "expirationDateTime": "2017-06-11T14:04:45.438Z",
//   "nextExpectedRanges": [
//     "983040-1366806"
//   ]
// }
// 
// ---- Chunk 2 uploaded ----
//   this chunkSize = 327680
//   this content-range: bytes 983040-1310719/1366807
// {
//   "expirationDateTime": "2017-06-11T14:04:45.438Z",
//   "nextExpectedRanges": [
//     "1310720-1366806"
//   ]
// }
// 
// ---- Chunk 3 uploaded ----
//   this chunkSize = 56087
//   this content-range: bytes 1310720-1366806/1366807
// {
//   "createdBy": {
//     "application": {
//       "displayName": "Chilkat",
//       "id": "441c9990"
//     },
//     "user": {
//       "id": "3a33fceb9b74cc15"
//     }
//   },
//   "createdDateTime": "2017-06-04T14:04:47.247Z",
//   "cTag": "aYzozQTMzRkNFQjlCNzRDQzE1ITQ4NjguMjU3",
//   "eTag": "aM0EzM0ZDRUI5Qjc0Q0MxNSE0ODY4LjA",
//   "id": "3A33FCEB9B74CC15!4868",
//   "lastModifiedBy": {
//     "application": {
//       "displayName": "Chilkat",
//       "id": "441c9990"
//     },
//     "user": {
//       "id": "3a33fceb9b74cc15"
//     }
//   },
//   "lastModifiedDateTime": "2017-06-04T14:04:47.247Z",
//   "name": "big.zip",
//   "parentReference": {
//     "driveId": "3a33fceb9b74cc15",
//     "id": "3A33FCEB9B74CC15!4862",
//     "name": "someFolder",
//     "path": "/drive/root:/someFolder"
//   },
//   "size": 1366807,
//   "webUrl": "https://1drv.ms/u/s!ABXMdJvr_DM6pgQ",
//   "file": {
//     "hashes": {
//       "sha1Hash": "252059AA13004220DB912B97D4D3FF9599CCD8D9"
//     },
//     "mimeType": "application/zip"
//   },
//   "fileSystemInfo": {
//     "createdDateTime": "2017-06-04T14:04:47.246Z",
//     "lastModifiedDateTime": "2017-06-04T14:04:47.246Z"
//   },
//   "tags": [
//   ],
//   "lenses": [
//   ]
// }
// 
// Response status = 201

CkJsonObject_Dispose(json);
CkHttp_Dispose(http);
CkJsonObject_Dispose(jsonSession);
CkFileAccess_Dispose(fac);
CkUrl_Dispose(uploadUrl);
CkHttpRequest_Dispose(req);
CkStringBuilder_Dispose(sbOffset);
CkStringBuilder_Dispose(sbNumBytes);
CkStringBuilder_Dispose(sbRange);

end;