I am trying to send parameters via the internal Datatables Ajax call to a VB.Net WebMethod

SportsavvyDev

So at this point I have searched the web to my best extent to find a solution to this problem but can't seem to find any that replicates it.

I have not been able to get a parameter to pass to a VB.Net WebMethod via the internal ajax call inside the DataTable() function. I originally was getting the Invalid JSON primitive: firstName error, however I learned that just required a JSON.stringify call to remedy. However when I did that stringify call, instead of it working it threw the same error with this now in place of the original error, "Invalid JSON primitive: %7B&1=%22&2=f&3=i&4=r&5=s&6=t&7=N&8=a&9=m&10=e&11=%22&12=%3A&13=%22&14=d&15=a&16=n&17=%22&18=%7D&reverse=&strReverse=.". At this point I am at a loss at what is happening, I will post my code below so maybe someone else might catch something I am missing.

AJAX:

    $(document).ready(function () {

        var params = { "firstName": "dan" };

        $("#invoicesTable").DataTable(
            {
                processing: true,
                ajax: {
                    type: "POST",
                    url: "Reports/DemoReport.aspx/GetReport",
                    data: JSON.stringify(params),
                    contentType: "Application/json; charset=utf-8",
                    responseType: "json",

                    //manipulate the returned data from the ajax call
                    dataSrc: function (json) {
                        //access d value from JSON since that contains the array of data
                        return json.d;
                    }
                },
                "language": {
                    processing: '<i class="fa fa-spinner fa-spin fa-3x fa-fw"></i><span style="color:red;">Loading...</span> '
                },
                //columns are always lowercase first letters
                columns: [
                    { "data": "checkboxes" },
                    { "data": "registrationKey" },
                    { "data": "registrationDate" },
                    { "data": "amountPaid" },
                ],

                dom: 'Bfrtip', //Required for setup

                //defines all of the header buttons
                buttons: [
                    //page length for render
                    'pageLength',
                    //excel export (customized for visable column export)
                    {
                        extend: 'excelHtml5',
                        exportOptions: {
                            columns: ':visible'
                        }
                    },
                    //csv export (customized for visable column export)
                    {
                        extend: 'csvHtml5',
                        exportOptions: {
                            columns: ':visible'
                        }
                    },
                    //pdf export (customized for visable column export)
                    {
                        extend: 'pdfHtml5',
                        exportOptions: {
                            columns: ':visible'
                        }
                    },
                    //column visabilty
                    'colvis'
                ],
                //add a checkbox to the first column
                columnDefs: [{
                   orderable: false,
                    className: 'select-checkbox',
                    targets: 0
                }
                ],
                //selection option general settings
                select: {
                    style: 'multi'
                },
                order: [[1, 'desc']] //have an order set at the start
            }
        )

    });

VB.NET:

<ScriptService()> _
Partial Class Reports_DemoReport
    Inherits System.Web.UI.Page


'Make a web method of this function so Ajax calls can reach it
<ScriptMethod(ResponseFormat:=ResponseFormat.Json)> _
<WebMethod()> _ 
Public Shared Function GetReport(ByVal firstName As String) As List(Of RegistrationReportLine)
    Try

             Dim constr As String = ConfigurationManager.ConnectionStrings("soaDB").ConnectionString
            Using con As New SqlConnection(constr)
                Using cmd As New SqlCommand("SELECT RegistrationKey, RegistrationDate, AmountPaid " & _
                                " FROM Registration")
                    cmd.Connection = con
                    Dim registrations As New List(Of RegistrationReportLine)()
                    con.Open()
                    Using sdr As SqlDataReader = cmd.ExecuteReader()
                        While sdr.Read()
                            registrations.Add(New RegistrationReportLine() With { _
                             .amountPaid = sdr("AmountPaid").ToString(), _
                             .registrationDate = sdr("RegistrationDate").ToString(), _
                             .registrationKey = sdr("RegistrationKey").ToString() _
                            })
                        End While
                    End Using
                    con.Close()
                    Return registrations
                End Using
            End Using

    Catch ex As Exception
        LogError(ex.Message)
    End Try
End Function
End Class

Model(Also VB.NET):

'Model to pass data back upon    
Public Class RegistrationReportLine
    'checkboxes
    Public Readonly Property checkboxes() As String
        Get
            Return ""
        End Get
    End Property

    'registration keys
    Private _registrationKey As String
    Public Property registrationKey() As String
        Get
            Return _registrationKey
        End Get
        Set(ByVal value As String)
            _registrationKey = value
        End Set
    End Property

    'registration dates
    Private _registrationDate As String
    Public Property registrationDate() As String
        Get
            Return _registrationDate
        End Get
        Set(ByVal value As String)
            _registrationDate = value
        End Set
    End Property

    'amount Paid
    Private _amountPaid As String
    Public Property amountPaid() As String
        Get
            Return _amountPaid
        End Get
        Set(ByVal value As String)
            _amountPaid = value
        End Set
    End Property
End Class

allan

You'd need to ask on SO or a VB.NET specific forum for help with the VB aspect. The client-side javascript looks okay - but to check, have a look in the Network tab of your browser's inspector and check the "Headers" for the data submitted to the server. What does it show?

Allan

SportsavvyDev

Hey Allan,

It was an internal server error so very likely it is a VB.Net issue.

SportsavvyDev

Hey Allan,

It was an internal server error so very likely it is a VB.Net issue.