Xojo Plugin Requires Chilkat v11.7.0+

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.

Xojo Plugin

Dim success As Boolean
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.
Dim curl As New Chilkat.HttpCurl
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 New Chilkat.StringBuilder
Dim setupReplacements As Int32

//  Register findParent; registration sends no request.
success = setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("findParent",setupCommand.GetAsString())
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

//  Register findFolder; registration sends no request.
success = setupCommand.SetString("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 = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("findFolder",setupCommand.GetAsString())
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

//  Register findFile; registration sends no request.
success = setupCommand.SetString("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 = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("findFile",setupCommand.GetAsString())
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

//  Register findDestination; registration sends no request.
success = setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("findDestination",setupCommand.GetAsString())
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

//  Register getFileDetails; registration sends no request.
success = setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("getFileDetails",setupCommand.GetAsString())
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

//  Register getEnterprise; registration sends no request.
success = setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/users/me?fields=enterprise"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("getEnterprise",setupCommand.GetAsString())
If (success <> True) Then
    System.DebugLog(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
    System.DebugLog(curl.LastErrorText)
    Return
End If

success = curl.AddOutput2("findFolder","entries","name","{{folder_name}}",True,"id","folder_id")
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

success = curl.AddOutput2("findFile","entries","name","{{file_name}}",True,"id","file_id")
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

success = curl.AddOutput2("findDestination","entries","name","{{destination_name}}",True,"id","destination_id")
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

success = curl.AddOutput("getFileDetails","file_version.id","file_version_id")
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

success = curl.AddOutput("getFileDetails","sha1","file_sha1")
If (success <> True) Then
    System.DebugLog(curl.LastErrorText)
    Return
End If

success = curl.AddOutput("getEnterprise","enterprise.id","enterprise_id")
If (success <> True) Then
    System.DebugLog(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
parentName = "/"
Dim folderName As String
folderName = "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 New Chilkat.StringBuilder
success = authorizedCommand1.SetString("curl -X GET ""https://api.box.com/2.0/folders/{{folder_id}}?fields=id"" -H ""Authorization: Bearer {{access_token}}""")
Dim headerReplacement1 As Int32
headerReplacement1 = authorizedCommand1.Replace("{{access_token}}",curl.GetVar("access_token"))
success = curl.DoYourThing(authorizedCommand1.GetAsString())
If ((success <> True) Or (curl.StatusCode <> 200)) Then
    System.DebugLog("Box request failed. HTTP status: " + Str(curl.StatusCode))
    System.DebugLog("Failure reason: " + Str(curl.FailReason))
    System.DebugLog(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
localPath = "qa_data/large-document.zip"
Dim file As New Chilkat.FileAccess
//  Check the decimal size before converting so an oversized file cannot overflow int.
Dim sizeString As String
sizeString = file.FileSizeStr(localPath)
If (file.LastMethodSuccess <> True) Then
    System.DebugLog(file.LastErrorText)
    Return
End If

Dim sizeText As New Chilkat.StringBuilder
success = sizeText.SetString(sizeString)
Dim sizeMatch As New Chilkat.JsonObject
If (sizeText.RegexMatch("^([0-9]{1,9}|1[0-9]{9}|2000000000)$",sizeMatch,100) <> 1) Then
    System.DebugLog("Choose an input between 20 MB and 2 GB for this example.")
    Return
End If

Dim fileSize As Int32
fileSize = Val(sizeString)
If (fileSize < 20971520) Then
    System.DebugLog("Choose an input between 20 MB and 2 GB for this example.")
    Return
End If

Dim http As New Chilkat.Http
http.AuthToken = curl.GetVar("access_token")
Dim response As New Chilkat.HttpResponse
Dim request As New Chilkat.JsonObject
success = request.UpdateString("folder_id",curl.GetVar("folder_id"))
success = request.UpdateString("file_name","large-document.zip")
success = 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
    System.DebugLog(http.LastErrorText)
    Return
End If

If (response.StatusCode <> 201) Then
    System.DebugLog(response.BodyStr)
    Return
End If

Dim session As New Chilkat.JsonObject
success = session.Load(response.BodyStr)
If (success <> True) Then
    System.DebugLog(session.LastErrorText)
    Return
End If

success = session.WriteFile("qa_output/box_upload_session.json")
If (success <> True) Then
    System.DebugLog(session.LastErrorText)
    Return
End If

Dim partSize As Int32
partSize = session.IntOf("part_size")
Dim uploadUrl As String
uploadUrl = session.StringOf("session_endpoints.upload_part")
Dim commitUrl As String
commitUrl = session.StringOf("session_endpoints.commit")
If ((partSize <= 0) Or (uploadUrl = "") Or (commitUrl = "")) Then
    System.DebugLog("Invalid session response.")
    Return
End If

Dim hash As New Chilkat.Crypt2
hash.HashAlgorithm = "sha1"
hash.EncodingMode = "base64"
Dim fileDigest As String
fileDigest = hash.HashFileENC(localPath)
If (hash.LastMethodSuccess <> True) Then
    System.DebugLog(hash.LastErrorText)
    Return
End If

success = file.FileOpen(localPath,2147483648,1,3,0)
If (success <> True) Then
    System.DebugLog(file.LastErrorText)
    Return
End If

Dim commit As New Chilkat.JsonObject
Dim partResponse As New Chilkat.JsonObject
Dim chunk As New Chilkat.BinData
Dim range As New Chilkat.StringBuilder
Dim digestHeader As New Chilkat.StringBuilder
Dim offset As Int32
offset = 0
Dim partIndex As Int32
partIndex = 0
Dim partLength As Int32
Dim lastByte As Int32
Dim partDigest As String
While offset < fileSize
    success = chunk.Clear()
    success = file.FileReadBd(partSize,chunk)
    If (success <> True) Then
        System.DebugLog(file.LastErrorText)
        file.FileClose 
        Return
    End If

    partLength = chunk.NumBytes
    If (partLength <= 0) Then
        System.DebugLog("Unexpected end of file.")
        file.FileClose 
        Return
    End If

    lastByte = offset + (partLength - 1)
    range.Clear 
    success = range.Append("bytes ")
    success = range.AppendInt(offset)
    success = range.Append("-")
    success = range.AppendInt(lastByte)
    success = range.Append("/")
    success = range.AppendInt(fileSize)
    partDigest = hash.HashBdENC(chunk)
    If (hash.LastMethodSuccess <> True) Then
        System.DebugLog(hash.LastErrorText)
        file.FileClose 
        Return
    End If

    success = digestHeader.SetString("sha=")
    success = 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
        System.DebugLog("Part failed. HTTP status: " + Str(response.StatusCode))
        System.DebugLog(response.BodyStr)
        System.DebugLog("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.
    success = commit.UpdateString("parts[i].part_id",partResponse.StringOf("part.part_id"))
    success = commit.UpdateInt("parts[i].offset",partResponse.IntOf("part.offset"))
    success = commit.UpdateInt("parts[i].size",partResponse.IntOf("part.size"))
    success = commit.UpdateString("parts[i].sha1",partResponse.StringOf("part.sha1"))
    success = commit.WriteFile("qa_output/box_upload_parts.json")
    If (success <> True) Then
        System.DebugLog(commit.LastErrorText)
        file.FileClose 
        Return
    End If

    offset = offset + partLength
    partIndex = partIndex + 1
Wend
file.FileClose 
http.RemoveRequestHeader "Content-Range"
success = digestHeader.SetString("sha=")
success = digestHeader.Append(fileDigest)
http.SetRequestHeader "Digest",digestHeader.GetAsString()
Dim attempts As Int32
attempts = 0
Dim waitSeconds As Int32
Dim retryHeader As New Chilkat.StringBuilder
Dim retryMatch As New Chilkat.JsonObject
Dim completed As Boolean
completed = False
While (attempts < 10) And (completed = False)
    success = http.HttpJson("POST",commitUrl,commit,"application/json",response)
    If (success <> True) Then
        System.DebugLog("Commit failed: " + Str(response.StatusCode))
        System.DebugLog(response.BodyStr)
        Return
    End If

    If (response.StatusCode = 201) Then
        completed = True
    Else
        If (response.StatusCode <> 202) Then
            System.DebugLog("Unexpected commit status: " + Str(response.StatusCode))
            Return
        End If

        //  Box's asynchronous commit response supplies Retry-After in seconds.
        success = retryHeader.SetString(response.GetHeaderField("Retry-After"))
        If (retryHeader.RegexMatch("^[0-9]{1,2}$",retryMatch,100) <> 1) Then
            System.DebugLog("Commit pending. Preserve the session and inspect Retry-After before resuming: " + retryHeader.GetAsString())
            Return
        End If

        waitSeconds = Val(retryHeader.GetAsString())
        If ((waitSeconds < 1) Or (waitSeconds > 60)) Then
            System.DebugLog("Commit pending. Resume commit after Retry-After: " + response.GetHeaderField("Retry-After"))
            Return
        End If

        http.SleepMs waitSeconds * 1000
    End If

    attempts = attempts + 1
Wend
If (completed = False) Then
    System.DebugLog("Commit still pending; retain session and part manifests to resume commit later.")
    Return
End If

System.DebugLog("Upload committed: " + response.BodyStr)