Async file upload and async PDF to CSV | VB.NET | PDF To CSV APIByteScout PDF Extractor SDK

Async file upload and async PDF to CSV | VB.NET | PDF To CSV API

Module1.vb:

VB
Imports System.IO
Imports System.Net
Imports System.Threading
Imports Newtonsoft.Json
Imports Newtonsoft.Json.Linq

Module Module1

    ' The authentication key (API Key).
    ' Get your own by registering at https://app.pdf.co/documentation/api
    Const API_KEY As String = "***********************************"

    ' Source PDF file
    Const SourceFile As String = ".\sample.pdf"
    ' Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'.
    Const Pages As String = ""
    ' PDF document password. Leave empty for unprotected documents.
    Const Password As String = ""
    ' Destination CSV file name
    Const DestinationFile As String = ".\result.csv"
    ' (!) Make asynchronous job
    Const Async As Boolean = True

    Sub Main()

        ' Create standard .NET web client instance
        Dim webClient As WebClient = New WebClient()

        ' Set API Key
        webClient.Headers.Add("x-api-key", API_KEY)

        ' 1. RETRIEVE THE PRESIGNED URL TO UPLOAD THE FILE.
        ' * If you already have a direct file URL, skip to the step 3.

        ' Prepare URL for `Get Presigned URL` API call
        Dim query As String = Uri.EscapeUriString(String.Format(
            "https://api.pdf.co/v1/file/upload/get-presigned-url?contenttype=application/octet-stream&name={0}",
            Path.GetFileName(SourceFile)))

        Try
            ' Execute request
            Dim response As String = webClient.DownloadString(query)

            ' Parse JSON response
            Dim json As JObject = JObject.Parse(response)

            If json("error").ToObject(Of Boolean) = False Then
                ' Get URL to use for the file upload
                Dim uploadUrl As String = json("presignedUrl").ToString()
                ' Get URL of uploaded file to use with later API calls
                Dim uploadedFileUrl As String = json("url").ToString()

                ' 2. UPLOAD THE FILE TO CLOUD.

                webClient.Headers.Add("content-type", "application/octet-stream")
                webClient.UploadFile(uploadUrl, "PUT", SourceFile) ' You can use UploadData() instead if your file is byte array or Stream

                ' Set JSON content type
                webClient.Headers.Add("Content-Type", "application/json")

                ' 3. CONVERT UPLOADED PDF FILE TO CSV

                ' Prepare URL for `PDF To CSV` API call
                Dim url As String = "https://api.pdf.co/v1/pdf/convert/to/csv"

                ' Prepare requests params as JSON
                ' See documentation: https : //apidocs.pdf.co
                Dim parameters As New Dictionary(Of String, Object)
                parameters.Add("name", Path.GetFileName(DestinationFile))
                parameters.Add("password", Password)
                parameters.Add("pages", Pages)
                parameters.Add("url", uploadedFileUrl)
                parameters.Add("async", Async)

                ' Convert dictionary of params to JSON
                Dim jsonPayload As String = JsonConvert.SerializeObject(parameters)

                Try
                    ' Execute POST request with JSON payload
                    response = webClient.UploadString(url, jsonPayload)

                    ' Parse JSON response
                    json = JObject.Parse(response)

                    If json("error").ToObject(Of Boolean) = False Then

                        ' Asynchronous job ID
                        Dim jobId As String = json("jobId").ToString()
                        ' URL of generated CSV file that will available after the job completion
                        Dim resultFileUrl As String = json("url").ToString()

                        ' Check the job status in a loop. 
                        ' If you don't want to pause the main thread you can rework the code 
                        ' to use a separate thread for the status checking and completion.
                        Do
                            Dim status As String = CheckJobStatus(jobId) ' Possible statuses: "working", "failed", "aborted", "success".

                            ' Display timestamp and status (for demo purposes)
                            Console.WriteLine(DateTime.Now.ToLongTimeString() + ": " + status)

                            If status = "success" Then

                                ' Download CSV file
                                webClient.DownloadFile(resultFileUrl, DestinationFile)

                                Console.WriteLine("Generated CSV file saved as ""{0}"" file.", DestinationFile)
                                Exit Do

                            ElseIf status = "working" Then

                                ' Pause for a few seconds
                                Thread.Sleep(3000)

                            Else

                                Console.WriteLine(status)
                                Exit Do

                            End If

                        Loop

                    Else
                        Console.WriteLine(json("message").ToString())
                    End If

                Catch ex As WebException
                    Console.WriteLine(ex.ToString())
                End Try

            End If

        Catch ex As WebException
            Console.WriteLine(ex.ToString())
        End Try

        webClient.Dispose()


        Console.WriteLine()
        Console.WriteLine("Press any key...")
        Console.ReadKey()

    End Sub

    ''' <summary>
    ''' Check job status
    ''' </summary>
    Function CheckJobStatus(jobId As String) As String

        Using webClient As WebClient = New WebClient()

            ' Set API Key
            webClient.Headers.Add("x-api-key", API_KEY)

            Dim url As String = "https://api.pdf.co/v1/job/check?jobid=" + jobId

            Dim response As String = webClient.DownloadString(url)
            Dim json As JObject = JObject.Parse(response)

            Return Convert.ToString(json("status"))

        End Using

    End Function


End Module