Delphi DLL Requires Chilkat v11.7.0+
Delphi DLL
Box: Upload a Large File in Parts and Commit the Session
See more Box Examples
Run the reusable setup once per HttpCurl object, then select names and execute the operation. The setup is repeated here only to make this published example independently runnable. Resolve documents by name, then perform the explicit chunked-upload session, part, and commit loop. Supports 20 MB through 2 GB using int. Saves recovery information and honors bounded commit Retry-After.
See the Box API guide for setup and the complete workflow.
Chilkat Delphi DLL Downloads
var
success: Boolean;
curl: HCkHttpCurl;
setupCommand: HCkStringBuilder;
setupReplacements: Integer;
parentName: PWideChar;
folderName: PWideChar;
authorizedCommand1: HCkStringBuilder;
headerReplacement1: Integer;
localPath: PWideChar;
file: HCkFileAccess;
sizeString: PWideChar;
sizeText: HCkStringBuilder;
sizeMatch: HCkJsonObject;
fileSize: Integer;
http: HCkHttp;
response: HCkHttpResponse;
request: HCkJsonObject;
session: HCkJsonObject;
partSize: Integer;
uploadUrl: PWideChar;
commitUrl: PWideChar;
hash: HCkCrypt2;
fileDigest: PWideChar;
commit: HCkJsonObject;
partResponse: HCkJsonObject;
chunk: HCkBinData;
range: HCkStringBuilder;
digestHeader: HCkStringBuilder;
offset: Integer;
partIndex: Integer;
partLength: Integer;
lastByte: Integer;
partDigest: PWideChar;
attempts: Integer;
waitSeconds: Integer;
retryHeader: HCkStringBuilder;
retryMatch: HCkJsonObject;
completed: Boolean;
begin
success := False;
// Requires Chilkat 11.7.0 or later and a previously unlocked Chilkat bundle.
// See Global Unlock Sample.
// Guide: Box API Guide.
success := False;
// BEGIN ONE-TIME SETUP
// This block is repeated so each published example can run on its own.
// In an application, run the setup example once and pass the SAME curl object
// to operation code below. Do not recreate it for every operation.
// See Reusable Box HttpCurl Setup.
curl := CkHttpCurl_Create();
CkHttpCurl_SetVar(curl,'access_token','BOX_ACCESS_TOKEN');
CkHttpCurl_SetVar(curl,'parent_name','/');
// Box's fixed root ID is an implementation detail; callers supply names.
CkHttpCurl_SetVar(curl,'parent_id','0');
setupCommand := CkStringBuilder_Create();
// Register findParent; registration sends no request.
CkStringBuilder_SetString(setupCommand,'curl -X GET "https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := CkStringBuilder_Replace(setupCommand,'ACCESS_TOKEN',CkHttpCurl__getVar(curl,'access_token'));
success := CkHttpCurl_AddFunction(curl,'findParent',CkStringBuilder__getAsString(setupCommand));
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
// Register findFolder; registration sends no request.
CkStringBuilder_SetString(setupCommand,'curl -X GET "https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := CkStringBuilder_Replace(setupCommand,'ACCESS_TOKEN',CkHttpCurl__getVar(curl,'access_token'));
success := CkHttpCurl_AddFunction(curl,'findFolder',CkStringBuilder__getAsString(setupCommand));
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
// Register findFile; registration sends no request.
CkStringBuilder_SetString(setupCommand,'curl -X GET "https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := CkStringBuilder_Replace(setupCommand,'ACCESS_TOKEN',CkHttpCurl__getVar(curl,'access_token'));
success := CkHttpCurl_AddFunction(curl,'findFile',CkStringBuilder__getAsString(setupCommand));
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
// Register findDestination; registration sends no request.
CkStringBuilder_SetString(setupCommand,'curl -X GET "https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := CkStringBuilder_Replace(setupCommand,'ACCESS_TOKEN',CkHttpCurl__getVar(curl,'access_token'));
success := CkHttpCurl_AddFunction(curl,'findDestination',CkStringBuilder__getAsString(setupCommand));
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
// Register getFileDetails; registration sends no request.
CkStringBuilder_SetString(setupCommand,'curl -X GET "https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := CkStringBuilder_Replace(setupCommand,'ACCESS_TOKEN',CkHttpCurl__getVar(curl,'access_token'));
success := CkHttpCurl_AddFunction(curl,'getFileDetails',CkStringBuilder__getAsString(setupCommand));
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
// Register getEnterprise; registration sends no request.
CkStringBuilder_SetString(setupCommand,'curl -X GET "https://api.box.com/2.0/users/me?fields=enterprise" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := CkStringBuilder_Replace(setupCommand,'ACCESS_TOKEN',CkHttpCurl__getVar(curl,'access_token'));
success := CkHttpCurl_AddFunction(curl,'getEnterprise',CkStringBuilder__getAsString(setupCommand));
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
// Register output rules once. Chilkat 11.7.0 evaluates {{name}} variables
// when extracting each output, using the current value at that time.
success := CkHttpCurl_AddOutput2(curl,'findParent','entries','name','{{parent_name}}',True,'id','parent_id');
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
success := CkHttpCurl_AddOutput2(curl,'findFolder','entries','name','{{folder_name}}',True,'id','folder_id');
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
success := CkHttpCurl_AddOutput2(curl,'findFile','entries','name','{{file_name}}',True,'id','file_id');
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
success := CkHttpCurl_AddOutput2(curl,'findDestination','entries','name','{{destination_name}}',True,'id','destination_id');
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
success := CkHttpCurl_AddOutput(curl,'getFileDetails','file_version.id','file_version_id');
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
success := CkHttpCurl_AddOutput(curl,'getFileDetails','sha1','file_sha1');
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
success := CkHttpCurl_AddOutput(curl,'getEnterprise','enterprise.id','enterprise_id');
if (success <> True) then
begin
Memo1.Lines.Add(CkHttpCurl__lastErrorText(curl));
Exit;
end;
// END ONE-TIME SETUP
// The name lookups below assume each listing fits in one page (1000 items).
// Parent and destination names select root children; folder_name selects a child
// of parent_name. "/" selects the root parent. These are not arbitrary paths.
// BEGIN OPERATION -- keep the configured object when reusing it.
// Inputs are names. Retain cached IDs when the selected names have not changed.
parentName := '/';
folderName := 'documents';
if ((CkHttpCurl__getVar(curl,'parent_name') <> parentName) or ((parentName = '/') and (CkHttpCurl_VarDefined(curl,'parent_id') = False))) then
begin
CkHttpCurl_SetVar(curl,'parent_name',parentName);
CkHttpCurl_ClearVar(curl,'parent_id');
CkHttpCurl_ClearVar(curl,'folder_id');
CkHttpCurl_ClearVar(curl,'file_id');
CkHttpCurl_ClearVar(curl,'file_version_id');
CkHttpCurl_ClearVar(curl,'file_sha1');
if (parentName = '/') then
begin
CkHttpCurl_SetVar(curl,'parent_id','0');
end;
end;
if (CkHttpCurl__getVar(curl,'folder_name') <> folderName) then
begin
CkHttpCurl_SetVar(curl,'folder_name',folderName);
CkHttpCurl_ClearVar(curl,'folder_id');
CkHttpCurl_ClearVar(curl,'file_id');
CkHttpCurl_ClearVar(curl,'file_version_id');
CkHttpCurl_ClearVar(curl,'file_sha1');
end;
// Resolve the named destination first. HttpCurl does not expand variables
// inside multipart -F attributes in the tested build, so this upload is two phases.
CkHttpCurl_ClearTargetOutput(curl,'*');
authorizedCommand1 := CkStringBuilder_Create();
CkStringBuilder_SetString(authorizedCommand1,'curl -X GET "https://api.box.com/2.0/folders/{{folder_id}}?fields=id" -H "Authorization: Bearer {{access_token}}"');
headerReplacement1 := CkStringBuilder_Replace(authorizedCommand1,'{{access_token}}',CkHttpCurl__getVar(curl,'access_token'));
success := CkHttpCurl_DoYourThing(curl,CkStringBuilder__getAsString(authorizedCommand1));
if ((success <> True) or (CkHttpCurl_getStatusCode(curl) <> 200)) then
begin
Memo1.Lines.Add('Box request failed. HTTP status: ' + IntToStr(CkHttpCurl_getStatusCode(curl)));
Memo1.Lines.Add('Failure reason: ' + IntToStr(CkHttpCurl_getFailReason(curl)));
Memo1.Lines.Add(CkHttpCurl__responseBodyStr(curl));
Exit;
end;
// This example limits size to 2 GB so offsets fit all generated languages' integers.
// The source must not change during hashing or upload. Create qa_output first.
localPath := 'qa_data/large-document.zip';
file := CkFileAccess_Create();
// Check the decimal size before converting so an oversized file cannot overflow int.
sizeString := CkFileAccess__fileSizeStr(file,localPath);
if (CkFileAccess_getLastMethodSuccess(file) <> True) then
begin
Memo1.Lines.Add(CkFileAccess__lastErrorText(file));
Exit;
end;
sizeText := CkStringBuilder_Create();
CkStringBuilder_SetString(sizeText,sizeString);
sizeMatch := CkJsonObject_Create();
if (CkStringBuilder_RegexMatch(sizeText,'^([0-9]{1,9}|1[0-9]{9}|2000000000)$',sizeMatch,100) <> 1) then
begin
Memo1.Lines.Add('Choose an input between 20 MB and 2 GB for this example.');
Exit;
end;
fileSize := StrToInt(sizeString);
if (fileSize < 20971520) then
begin
Memo1.Lines.Add('Choose an input between 20 MB and 2 GB for this example.');
Exit;
end;
http := CkHttp_Create();
CkHttp_putAuthToken(http,CkHttpCurl__getVar(curl,'access_token'));
response := CkHttpResponse_Create();
request := CkJsonObject_Create();
CkJsonObject_UpdateString(request,'folder_id',CkHttpCurl__getVar(curl,'folder_id'));
CkJsonObject_UpdateString(request,'file_name','large-document.zip');
CkJsonObject_UpdateInt(request,'file_size',fileSize);
success := CkHttp_HttpJson(http,'POST','https://upload.box.com/api/2.0/files/upload_sessions',request,'application/json',response);
if (success <> True) then
begin
Memo1.Lines.Add(CkHttp__lastErrorText(http));
Exit;
end;
if (CkHttpResponse_getStatusCode(response) <> 201) then
begin
Memo1.Lines.Add(CkHttpResponse__bodyStr(response));
Exit;
end;
session := CkJsonObject_Create();
success := CkJsonObject_Load(session,CkHttpResponse__bodyStr(response));
if (success <> True) then
begin
Memo1.Lines.Add(CkJsonObject__lastErrorText(session));
Exit;
end;
success := CkJsonObject_WriteFile(session,'qa_output/box_upload_session.json');
if (success <> True) then
begin
Memo1.Lines.Add(CkJsonObject__lastErrorText(session));
Exit;
end;
partSize := CkJsonObject_IntOf(session,'part_size');
uploadUrl := CkJsonObject__stringOf(session,'session_endpoints.upload_part');
commitUrl := CkJsonObject__stringOf(session,'session_endpoints.commit');
if ((partSize <= 0) or (uploadUrl = '') or (commitUrl = '')) then
begin
Memo1.Lines.Add('Invalid session response.');
Exit;
end;
hash := CkCrypt2_Create();
CkCrypt2_putHashAlgorithm(hash,'sha1');
CkCrypt2_putEncodingMode(hash,'base64');
fileDigest := CkCrypt2__hashFileENC(hash,localPath);
if (CkCrypt2_getLastMethodSuccess(hash) <> True) then
begin
Memo1.Lines.Add(CkCrypt2__lastErrorText(hash));
Exit;
end;
success := CkFileAccess_FileOpen(file,localPath,2147483648,1,3,0);
if (success <> True) then
begin
Memo1.Lines.Add(CkFileAccess__lastErrorText(file));
Exit;
end;
commit := CkJsonObject_Create();
partResponse := CkJsonObject_Create();
chunk := CkBinData_Create();
range := CkStringBuilder_Create();
digestHeader := CkStringBuilder_Create();
offset := 0;
partIndex := 0;
while offset < fileSize do
begin
CkBinData_Clear(chunk);
success := CkFileAccess_FileReadBd(file,partSize,chunk);
if (success <> True) then
begin
Memo1.Lines.Add(CkFileAccess__lastErrorText(file));
CkFileAccess_FileClose(file);
Exit;
end;
partLength := CkBinData_getNumBytes(chunk);
if (partLength <= 0) then
begin
Memo1.Lines.Add('Unexpected end of file.');
CkFileAccess_FileClose(file);
Exit;
end;
lastByte := offset + (partLength - 1);
CkStringBuilder_Clear(range);
CkStringBuilder_Append(range,'bytes ');
CkStringBuilder_AppendInt(range,offset);
CkStringBuilder_Append(range,'-');
CkStringBuilder_AppendInt(range,lastByte);
CkStringBuilder_Append(range,'/');
CkStringBuilder_AppendInt(range,fileSize);
partDigest := CkCrypt2__hashBdENC(hash,chunk);
if (CkCrypt2_getLastMethodSuccess(hash) <> True) then
begin
Memo1.Lines.Add(CkCrypt2__lastErrorText(hash));
CkFileAccess_FileClose(file);
Exit;
end;
CkStringBuilder_SetString(digestHeader,'sha=');
CkStringBuilder_Append(digestHeader,partDigest);
CkHttp_SetRequestHeader(http,'Digest',CkStringBuilder__getAsString(digestHeader));
CkHttp_SetRequestHeader(http,'Content-Range',CkStringBuilder__getAsString(range));
success := CkHttp_HttpBd(http,'PUT',uploadUrl,chunk,'application/octet-stream',response);
if ((success <> True) or (CkHttpResponse_getStatusCode(response) <> 200)) then
begin
Memo1.Lines.Add('Part failed. HTTP status: ' + IntToStr(CkHttpResponse_getStatusCode(response)));
Memo1.Lines.Add(CkHttpResponse__bodyStr(response));
Memo1.Lines.Add('Inspect the saved session and server list_parts before retrying this part.');
CkFileAccess_FileClose(file);
Exit;
end;
success := CkJsonObject_Load(partResponse,CkHttpResponse__bodyStr(response));
if (success <> True) then
begin
CkFileAccess_FileClose(file);
Exit;
end;
CkJsonObject_putI(commit,partIndex);
// Copy the server's acknowledged part fields into the commit manifest.
CkJsonObject_UpdateString(commit,'parts[i].part_id',CkJsonObject__stringOf(partResponse,'part.part_id'));
CkJsonObject_UpdateInt(commit,'parts[i].offset',CkJsonObject_IntOf(partResponse,'part.offset'));
CkJsonObject_UpdateInt(commit,'parts[i].size',CkJsonObject_IntOf(partResponse,'part.size'));
CkJsonObject_UpdateString(commit,'parts[i].sha1',CkJsonObject__stringOf(partResponse,'part.sha1'));
success := CkJsonObject_WriteFile(commit,'qa_output/box_upload_parts.json');
if (success <> True) then
begin
Memo1.Lines.Add(CkJsonObject__lastErrorText(commit));
CkFileAccess_FileClose(file);
Exit;
end;
offset := offset + partLength;
partIndex := partIndex + 1;
end;
CkFileAccess_FileClose(file);
CkHttp_RemoveRequestHeader(http,'Content-Range');
CkStringBuilder_SetString(digestHeader,'sha=');
CkStringBuilder_Append(digestHeader,fileDigest);
CkHttp_SetRequestHeader(http,'Digest',CkStringBuilder__getAsString(digestHeader));
attempts := 0;
retryHeader := CkStringBuilder_Create();
retryMatch := CkJsonObject_Create();
completed := False;
while (attempts < 10) and (completed = False) do
begin
success := CkHttp_HttpJson(http,'POST',commitUrl,commit,'application/json',response);
if (success <> True) then
begin
Memo1.Lines.Add('Commit failed: ' + IntToStr(CkHttpResponse_getStatusCode(response)));
Memo1.Lines.Add(CkHttpResponse__bodyStr(response));
Exit;
end;
if (CkHttpResponse_getStatusCode(response) = 201) then
begin
completed := True;
end
else
begin
if (CkHttpResponse_getStatusCode(response) <> 202) then
begin
Memo1.Lines.Add('Unexpected commit status: ' + IntToStr(CkHttpResponse_getStatusCode(response)));
Exit;
end;
// Box's asynchronous commit response supplies Retry-After in seconds.
CkStringBuilder_SetString(retryHeader,CkHttpResponse__getHeaderField(response,'Retry-After'));
if (CkStringBuilder_RegexMatch(retryHeader,'^[0-9]{1,2}$',retryMatch,100) <> 1) then
begin
Memo1.Lines.Add('Commit pending. Preserve the session and inspect Retry-After before resuming: ' + CkStringBuilder__getAsString(retryHeader));
Exit;
end;
waitSeconds := StrToInt(CkStringBuilder__getAsString(retryHeader));
if ((waitSeconds < 1) or (waitSeconds > 60)) then
begin
Memo1.Lines.Add('Commit pending. Resume commit after Retry-After: ' + CkHttpResponse__getHeaderField(response,'Retry-After'));
Exit;
end;
CkHttp_SleepMs(http,waitSeconds * 1000);
end;
attempts := attempts + 1;
end;
if (completed = False) then
begin
Memo1.Lines.Add('Commit still pending; retain session and part manifests to resume commit later.');
Exit;
end;
Memo1.Lines.Add('Upload committed: ' + CkHttpResponse__bodyStr(response));
CkHttpCurl_Dispose(curl);
CkStringBuilder_Dispose(setupCommand);
CkStringBuilder_Dispose(authorizedCommand1);
CkFileAccess_Dispose(file);
CkStringBuilder_Dispose(sizeText);
CkJsonObject_Dispose(sizeMatch);
CkHttp_Dispose(http);
CkHttpResponse_Dispose(response);
CkJsonObject_Dispose(request);
CkJsonObject_Dispose(session);
CkCrypt2_Dispose(hash);
CkJsonObject_Dispose(commit);
CkJsonObject_Dispose(partResponse);
CkBinData_Dispose(chunk);
CkStringBuilder_Dispose(range);
CkStringBuilder_Dispose(digestHeader);
CkStringBuilder_Dispose(retryHeader);
CkJsonObject_Dispose(retryMatch);