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PDF Table Search from URL Asynchronously - VB.NET

PDF Find Table sample in VB.NET demonstrating ‘PDF Table Search from URL Asynchronously’

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
    Const API_KEY As String = "***********************************"

    ' Direct URL of source PDF file.
    ' You can also upload your own file into and use it as url. Check "Upload File" samples for code snippets:   
    Const SourceFileUrl As String = ""

    ' 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 = ""

    '(!) 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)

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

        ' Prepare URL for PDF Table Search API call.
        ' See documentation: https : //
		Dim url As String = ""

        ' Prepare requests params as JSON
        ' See documentation: https : //
        Dim parameters As New Dictionary(Of String, Object)
		parameters.Add("password", Password)
		parameters.Add("pages", Pages)
		parameters.Add("url", SourceFileUrl)
		parameters.Add("async", Async)

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

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

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

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

                ' Asynchronous job ID
                Dim jobId As String = json("jobId").ToString()

                ' URL of generated json 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.
                    Dim status = CheckJobStatus(jobId) ' Possible statuses: "working", "failed", "aborted", "success".

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

                    If (status = "success") Then
                        ' Execute request
                        Dim respFileJson As String = webClient.DownloadString(resultFileUrl)

                        ' Print JSON response

                        Exit Do
                    ElseIf (status = "working") Then
                        ' Pause for a few seconds
                        Exit Do
                    End If
            End If

        Catch ex As WebException
        End Try


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

    End Sub

    Function CheckJobStatus(ByVal jobId As String)

        Using webClient As New WebClient

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

            Dim url As String = "" & 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 Web API: the Web API with a set of tools for documents manipulation, data conversion, data extraction, splitting and merging of documents. Includes image recognition, built-in OCR, barcode generation and barcode decoders to decode bar codes from scans, pictures and pdf.

Get your API key here!

Download Source Code (.zip)

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