B4X Requires Chilkat v11.7.0+
B4X
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 B4X Downloads
Dim success As Boolean = 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.
Dim curl As ChilkatHttpCurl
curl.Initialize("curl")
curl.SetVar("access_token", "BOX_ACCESS_TOKEN")
curl.SetVar("parent_name", "/")
' Box's fixed root ID is an implementation detail; callers supply names.
curl.SetVar("parent_id", "0")
Dim setupCommand As ChilkatStringBuilder
setupCommand.Initialize
Dim setupReplacements As Int
' Register findParent; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("findParent", setupCommand.GetAsString)
If success <> True Then
Log(curl.LastErrorText)
Return
End If
' Register findFolder; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("findFolder", setupCommand.GetAsString)
If success <> True Then
Log(curl.LastErrorText)
Return
End If
' Register findFile; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("findFile", setupCommand.GetAsString)
If success <> True Then
Log(curl.LastErrorText)
Return
End If
' Register findDestination; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("findDestination", setupCommand.GetAsString)
If success <> True Then
Log(curl.LastErrorText)
Return
End If
' Register getFileDetails; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("getFileDetails", setupCommand.GetAsString)
If success <> True Then
Log(curl.LastErrorText)
Return
End If
' Register getEnterprise; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/users/me?fields=enterprise" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("getEnterprise", setupCommand.GetAsString)
If success <> True Then
Log(curl.LastErrorText)
Return
End If
' Register output rules once. Chilkat 11.7.0 evaluates {{name}} variables
' when extracting each output, using the current value at that time.
success = curl.AddOutput2("findParent", "entries", "name", "{{parent_name}}", True, "id", "parent_id")
If success <> True Then
Log(curl.LastErrorText)
Return
End If
success = curl.AddOutput2("findFolder", "entries", "name", "{{folder_name}}", True, "id", "folder_id")
If success <> True Then
Log(curl.LastErrorText)
Return
End If
success = curl.AddOutput2("findFile", "entries", "name", "{{file_name}}", True, "id", "file_id")
If success <> True Then
Log(curl.LastErrorText)
Return
End If
success = curl.AddOutput2("findDestination", "entries", "name", "{{destination_name}}", True, "id", "destination_id")
If success <> True Then
Log(curl.LastErrorText)
Return
End If
success = curl.AddOutput("getFileDetails", "file_version.id", "file_version_id")
If success <> True Then
Log(curl.LastErrorText)
Return
End If
success = curl.AddOutput("getFileDetails", "sha1", "file_sha1")
If success <> True Then
Log(curl.LastErrorText)
Return
End If
success = curl.AddOutput("getEnterprise", "enterprise.id", "enterprise_id")
If success <> True Then
Log(curl.LastErrorText)
Return
End If
' 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.
Dim parentName As String = "/"
Dim folderName As String = "documents"
If (curl.GetVar("parent_name") <> parentName) Or ((parentName = "/") And (curl.VarDefined("parent_id") = False)) Then
curl.SetVar("parent_name", parentName)
curl.ClearVar("parent_id")
curl.ClearVar("folder_id")
curl.ClearVar("file_id")
curl.ClearVar("file_version_id")
curl.ClearVar("file_sha1")
If parentName = "/" Then
curl.SetVar("parent_id", "0")
End If
End If
If curl.GetVar("folder_name") <> folderName Then
curl.SetVar("folder_name", folderName)
curl.ClearVar("folder_id")
curl.ClearVar("file_id")
curl.ClearVar("file_version_id")
curl.ClearVar("file_sha1")
End If
' Resolve the named destination first. HttpCurl does not expand variables
' inside multipart -F attributes in the tested build, so this upload is two phases.
curl.ClearTargetOutput("*")
Dim authorizedCommand1 As ChilkatStringBuilder
authorizedCommand1.Initialize
authorizedCommand1.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/{{folder_id}}?fields=id" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer {{access_token}}" & Chr(34))
Dim headerReplacement1 As Int = authorizedCommand1.Replace("{{access_token}}", curl.GetVar("access_token"))
success = curl.DoYourThing(authorizedCommand1.GetAsString)
If (success <> True) Or (curl.StatusCode <> 200) Then
Log("Box request failed. HTTP status: " & curl.StatusCode)
Log("Failure reason: " & curl.FailReason)
Log(curl.ResponseBodyStr)
Return
End If
' 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.
Dim localPath As String = "qa_data/large-document.zip"
Dim file As ChilkatFileAccess
file.Initialize
' Check the decimal size before converting so an oversized file cannot overflow int.
Dim sizeString As String = file.FileSizeStr(localPath)
If file.LastMethodSuccess <> True Then
Log(file.LastErrorText)
Return
End If
Dim sizeText As ChilkatStringBuilder
sizeText.Initialize
sizeText.SetString(sizeString)
Dim sizeMatch As ChilkatJsonObject
sizeMatch.Initialize
If sizeText.RegexMatch("^([0-9]{1,9}|1[0-9]{9}|2000000000)$", sizeMatch, 100) <> 1 Then
Log("Choose an input between 20 MB and 2 GB for this example.")
Return
End If
Dim fileSize As Int = sizeString
If fileSize < 20971520 Then
Log("Choose an input between 20 MB and 2 GB for this example.")
Return
End If
Dim http As ChilkatHttp
http.Initialize("http")
http.AuthToken = curl.GetVar("access_token")
Dim response As ChilkatHttpResponse
response.Initialize
Dim request As ChilkatJsonObject
request.Initialize
request.UpdateString("folder_id", curl.GetVar("folder_id"))
request.UpdateString("file_name", "large-document.zip")
request.UpdateInt("file_size", fileSize)
success = http.HttpJson("POST", "https://upload.box.com/api/2.0/files/upload_sessions", request, "application/json", response)
If success <> True Then
Log(http.LastErrorText)
Return
End If
If response.StatusCode <> 201 Then
Log(response.BodyStr)
Return
End If
Dim session As ChilkatJsonObject
session.Initialize
success = session.Load(response.BodyStr)
If success <> True Then
Log(session.LastErrorText)
Return
End If
success = session.WriteFile("qa_output/box_upload_session.json")
If success <> True Then
Log(session.LastErrorText)
Return
End If
Dim partSize As Int = session.IntOf("part_size")
Dim uploadUrl As String = session.StringOf("session_endpoints.upload_part")
Dim commitUrl As String = session.StringOf("session_endpoints.commit")
If (partSize <= 0) Or (uploadUrl = "") Or (commitUrl = "") Then
Log("Invalid session response.")
Return
End If
Dim hash As ChilkatCrypt2
hash.Initialize("hash")
hash.HashAlgorithm = "sha1"
hash.EncodingMode = "base64"
Dim fileDigest As String = hash.HashFileENC(localPath)
If hash.LastMethodSuccess <> True Then
Log(hash.LastErrorText)
Return
End If
success = file.FileOpen(localPath, 2147483648, 1, 3, 0)
If success <> True Then
Log(file.LastErrorText)
Return
End If
Dim commit As ChilkatJsonObject
commit.Initialize
Dim partResponse As ChilkatJsonObject
partResponse.Initialize
Dim chunk As ChilkatBinData
chunk.Initialize
Dim range As ChilkatStringBuilder
range.Initialize
Dim digestHeader As ChilkatStringBuilder
digestHeader.Initialize
Dim offset As Int = 0
Dim partIndex As Int = 0
Dim partLength As Int
Dim lastByte As Int
Dim partDigest As String
Do While offset < fileSize
chunk.Clear
success = file.FileReadBd(partSize, chunk)
If success <> True Then
Log(file.LastErrorText)
file.FileClose
Return
End If
partLength = chunk.NumBytes
If partLength <= 0 Then
Log("Unexpected end of file.")
file.FileClose
Return
End If
lastByte = offset + (partLength - 1)
range.Clear
range.Append("bytes ")
range.AppendInt(offset)
range.Append("-")
range.AppendInt(lastByte)
range.Append("/")
range.AppendInt(fileSize)
partDigest = hash.HashBdENC(chunk)
If hash.LastMethodSuccess <> True Then
Log(hash.LastErrorText)
file.FileClose
Return
End If
digestHeader.SetString("sha=")
digestHeader.Append(partDigest)
http.SetRequestHeader("Digest", digestHeader.GetAsString)
http.SetRequestHeader("Content-Range", range.GetAsString)
success = http.HttpBd("PUT", uploadUrl, chunk, "application/octet-stream", response)
If (success <> True) Or (response.StatusCode <> 200) Then
Log("Part failed. HTTP status: " & response.StatusCode)
Log(response.BodyStr)
Log("Inspect the saved session and server list_parts before retrying this part.")
file.FileClose
Return
End If
success = partResponse.Load(response.BodyStr)
If success <> True Then
file.FileClose
Return
End If
commit.I = partIndex
' Copy the server's acknowledged part fields into the commit manifest.
commit.UpdateString("parts[i].part_id", partResponse.StringOf("part.part_id"))
commit.UpdateInt("parts[i].offset", partResponse.IntOf("part.offset"))
commit.UpdateInt("parts[i].size", partResponse.IntOf("part.size"))
commit.UpdateString("parts[i].sha1", partResponse.StringOf("part.sha1"))
success = commit.WriteFile("qa_output/box_upload_parts.json")
If success <> True Then
Log(commit.LastErrorText)
file.FileClose
Return
End If
offset = offset + partLength
partIndex = partIndex + 1
Loop
file.FileClose
http.RemoveRequestHeader("Content-Range")
digestHeader.SetString("sha=")
digestHeader.Append(fileDigest)
http.SetRequestHeader("Digest", digestHeader.GetAsString)
Dim attempts As Int = 0
Dim waitSeconds As Int
Dim retryHeader As ChilkatStringBuilder
retryHeader.Initialize
Dim retryMatch As ChilkatJsonObject
retryMatch.Initialize
Dim completed As Boolean = False
Do While (attempts < 10) And (completed = False)
success = http.HttpJson("POST", commitUrl, commit, "application/json", response)
If success <> True Then
Log("Commit failed: " & response.StatusCode)
Log(response.BodyStr)
Return
End If
If response.StatusCode = 201 Then
completed = True
Else
If response.StatusCode <> 202 Then
Log("Unexpected commit status: " & response.StatusCode)
Return
End If
' Box's asynchronous commit response supplies Retry-After in seconds.
retryHeader.SetString(response.GetHeaderField("Retry-After"))
If retryHeader.RegexMatch("^[0-9]{1,2}$", retryMatch, 100) <> 1 Then
Log("Commit pending. Preserve the session and inspect Retry-After before resuming: " & retryHeader.GetAsString)
Return
End If
waitSeconds = retryHeader.GetAsString
If (waitSeconds < 1) Or (waitSeconds > 60) Then
Log("Commit pending. Resume commit after Retry-After: " & response.GetHeaderField("Retry-After"))
Return
End If
http.SleepMs(waitSeconds * 1000)
End If
attempts = attempts + 1
Loop
If completed = False Then
Log("Commit still pending; retain session and part manifests to resume commit later.")
Return
End If
Log("Upload committed: " & response.BodyStr)