Call server-side page function from client-side button click

I have an existing ASP application that I am migrating to ASP.net. In the ASP app I was using the Microsoft.XMLHTTP on a the client-side of a ASP page to retrieve data from another asp page using the Microsoft.XMLDOM object. The client page passes 3 tags columns, table and Criteria. The receiving page builds the SQL statement executes the query and returns the row with all the column data.  I am trying to convert it over to ASP.NET and I am getting errors on the xmlDOM.Load(Request.InputStream) on DLookup.aspx,  the code is listed below.


Someone suggested to use System.Net HTTP classes such as WebClient or WebRequest.


I have been searching Google and have not found any examples of client-side script.  Can someone give my some help in finding a solution?


*//Asp.net Client-Side Code Code//*


Set xmlHTTP = CreateObject("Microsoft.XMLHTTP")


xmlHTTP.open "POST", "/XMLFunctions/DLookup.aspx", False


               


strColumns = "CLIENT_NAME, REGION_DESC, LOGO, PHONE, ACCT_MGR, AFFILIATION, COORDINATOR_NAME, EXT, DESCRIPTION, COORD_CAS_ID"


' Send the columns, table and where clause


               


xmlHTTP.send("<REQUEST><sColumn>" & strColumns & "</sColumn><sTable>SIMBBA.V_WEB_HEADER_PLUS_ARCHIVE</sTable><sCriteria>PROFILE_NUM = " & ReqProfile &"</sCriteria></REQUEST>")


                         


Set xmlDOM = CreateObject("Microsoft.XMLDOM")


xmlDOM.loadXML(xmlHTTP.ResponseText)


     


If  xmlDOM.parseError <> 0 Then


Call msgbox ("Error :" & xmlDOM.ParseError.reason)


Exit Function


End If


                         


'Create the XML root that will contain all the tag elements     


Set xmlRoot = xmlDOM.getElementsByTagName("*")


               


'Loop through the collection of returned tags from the XML Function     


'If you are selecting more then one column you must increment the index and subtract from the length


'For i = 1 To (xmlRoot.length-1) for 2 columns, -2 for 3 columns, -3 for 4 columns etc...


For i = 1 To (xmlRoot.length-9)


'strResults = (xmlRoot.item(i+1).text for 2 columns), (+2 for 3 columns), (+ 3 for 4 columns) etc...


ReqClientName = xmlRoot.item(i).text 


ReqRegion  = xmlRoot.item(i+1).text 


ReqLogo  =xmlRoot.item(i+2).text 


ReqAcctMgrPhone  = xmlRoot.item(i+3).text 


ReqAcctMgr = xmlRoot.item(i+4).text 


ReqAffiliation = xmlRoot.item(i+5).text 


ReqProfileCoordinatorName = xmlRoot.item(i+6).text 


ReqCoordExt = xmlRoot.item(i+7).text 


ReqProfileDesc =xmlRoot.item(i+8).text 


ReqCoordCasID = xmlRoot.item(i+9).text 


i = i+9


'(i = i +2 for 3 columns), (+ 3 for 4 columns), (+ 4 for 5 columns)


Next 


Set xmlHTTP = Nothing


Set xmlDOM = Nothing


Set xmlRoot = Nothing     


*// End Client-Side Code //*


*// Start Server-Side Code//*


<%@ Page  Language="vb"Debug="true" EnableSessionState=true %>


<%@ Import Namespace="System.Data" %>


<%@ Import Namespace="System.Data.OracleClient"%>


<%@ Import Namespace="System.Web" %>


<%@ Import Namespace="System.Xml" %>


<script  Language="vb" runat="server">


  Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


  


     Dim oOracleConn As OracleConnection = New OracleConnection


        Dim xmlDOM As XmlDocument


        Dim strXML As String


        Dim sColumn As String


        Dim sTable As String


        Dim sCriteria As String


        Dim strSQL As String


        Dim dt As DataTable


        Dim dtCol As DataColumn


        Dim dtRow As DataRow


        Dim oCommand As OracleCommand


        Dim da As OracleDataAdapter


        Try


            strXML = "<RESPONSE>"


            xmlDOM.Load(Request.InputStream)


            sColumn = xmlDOM.DocumentElement.GetElementsByTagName("sColumn")(0).FirstChild.Value


            sTable = xmlDOM.DocumentElement.GetElementsByTagName("sTable")(0).FirstChild.Value


            sCriteria = xmlDOM.DocumentElement.GetElementsByTagName("sCriteria")(0).FirstChild.Value


            'Specify our SQL statement


            strSQL = "SELECT " & sColumn & " FROM " & sTable & " Where " & sCriteria


            oOracleConn.ConnectionString = Session("ConnectionString")


            oOracleConn.Open()


            oCommand = New OracleCommand(strSQL, oOracleConn)


            da = New OracleDataAdapter(strSQL, oOracleConn)


            da.Fill(dt)


            If dt.Rows.Count < 1 Then


                strXML = strXML & "<RESULTS>NOTFOUND</RESULTS>"


            Else


                For Each dtCol In dt.Columns


                    sColumn = dtCol.ColumnName


                    strXML = strXML & "<" & sColumn & ">" & Replace(dtRow(dtCol).ToString(), "&", "chr(38)") & "</" & sColumn & ">"


                Next


            End If


        Catch exp As Exception


            strXML = strXML & "Error Occured: " & exp.ToString


        Finally


            da = Nothing


            da.Dispose()


            oCommand.Dispose()


            oOracleConn.Close()


            oOracleConn.Dispose()


        End Try


        strXML = strXML & "</RESPONSE>"


        Response.Write(strXML)


        Response.End()


End Sub     


</script>


*// End Server-Side Code//*

The type of stuff you are doing looks better to be done on server-side, i think. The pointers you got regarding that is right, use System.Net to get the other pages, process it and send back to the user.


You could either use post-back (using form or javascript) or use a asp:button (?) control with a server-side on_click handler. both results in the same thing. Leave the details to you...


System.Net usage is like this...

        Dim Request As System.Net.HttpWebRequest


        Dim Response As System.Net.HttpWebResponse


        Dim StreamHandler As System.IO.StreamReader


        ' Send the request to the server


        Try


            Request = System.Net.WebRequest.Create(URL)


            'Request.Expect = "text/html"


            Response = CType(Request.GetResponse, System.Net.WebResponse)


            If Request.HaveResponse Then


                If Response.StatusCode = Net.HttpStatusCode.OK Then


                    StreamHandler = New System.IO.StreamReader(Response.GetResponseStream())


                    GetPage = StreamHandler.ReadToEnd


                End If


            End If


        Catch e As System.Net.WebException


            'Handle...


            Exit Try


        Finally


        End Try

:: Fozylet