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'
' File: Payment_success.aspx.vb
'
' Facility: The unit contains the Payment_success class
'
' Abstract: This class is intended for processing of requests that come
' from the PayPal server during testing. Besides, this class
' creates payment reports and records the process of interaction
' with the PayPal server.
'
' Environment: VC 8.0
'
' Author: KB_Soft Group Ltd.
'
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Imports System.Net
Imports System.IO
Imports System.Globalization
Imports System.Configuration.ConfigurationManager
Imports System.Data
Imports System.Xml
Partial Class Payment_success
Inherits System.Web.UI.Page
' the parameters to be checked
Private business As String = AppSettings("BusinessEmail")
Private currency_code As String = AppSettings("CurrencyCode")
Shared requests As DataSet = New DataSet()
Shared responses As DataSet = New DataSet()
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
' The code of this procedure should be used only to test requests processing,
' since this code is needed only when the request sent to PayPal has rm <> 1;
' otherwise the code can be deleted.
Dim ci As CultureInfo = New CultureInfo("en-us")
Dim requestsFile As String = Server.MapPath("~/App_Data/PaymentRequests.xml")
requests.Clear()
If File.Exists(requestsFile) Then
requests.ReadXml(requestsFile)
Else
KBSoft.Carts.CreateXml(requestsFile, "Requests")
requests.ReadXml(requestsFile)
End If
Dim responseFile As String = Server.MapPath("~/App_Data/PaymentResponses.xml")
responses.Clear()
If File.Exists(responseFile) Then
responses.ReadXml(responseFile)
Else
KBSoft.Carts.CreateXml(responseFile, "Responses")
responses.ReadXml(responseFile)
End If
Dim strFormValues As String = Encoding.ASCII.GetString(Request.BinaryRead(Request.ContentLength))
Dim strNewValue
' getting the URL to work with
Dim URL As String
If AppSettings("UseSandbox").ToString = "true" Then
URL = "https://www.sandbox.paypal.com/cgi-bin/webscr"
Else
URL = "https://www.paypal.com/cgi-bin/webscr"
End If
' Create the request back
Dim req As HttpWebRequest = CType(WebRequest.Create(URL), HttpWebRequest)
' Set values for the request back
req.Method = "POST"
req.ContentType = "application/x-www-form-urlencoded"
strNewValue = strFormValues + "&cmd=_notify-validate"
req.ContentLength = strNewValue.Length
' Write the request back IPN strings
Dim stOut As StreamWriter = New StreamWriter(req.GetRequestStream(), _
Encoding.ASCII)
stOut.Write(strNewValue)
stOut.Close()
'send the request, read the response
Dim strResponse As HttpWebResponse = CType(req.GetResponse(), HttpWebResponse)
Dim IPNResponseStream As Stream = strResponse.GetResponseStream
Dim encode As Encoding = System.Text.Encoding.GetEncoding("utf-8")
Dim readStream As New StreamReader(IPNResponseStream, encode)
Dim read(256) As [Char]
' Reads 256 characters at a time.
Dim count As Integer = readStream.Read(read, 0, 256)
While count > 0
' Dumps the 256 characters to a string
Dim IPNResponse As New [String](read, 0, count)
count = readStream.Read(read, 0, 256)
Dim amount As String
Try
' getting the total cost of goods in the cart for a request identified stored in the "custom" variable
amount = GetRequestPrice(Request("custom").ToString)
If amount = "" Then
KBSoft.Carts.WriteFile("Error in payment_success: amount = """)
readStream.Close()
strResponse.Close()
Return
End If
Catch ex As Exception
KBSoft.Carts.WriteFile("Error in payment_success: " + ex.Message)
readStream.Close()
strResponse.Close()
Return
End Try
Dim provider As NumberFormatInfo = New NumberFormatInfo()
provider.NumberDecimalSeparator = "."
provider.NumberGroupSeparator = ","
provider.NumberGroupSizes = New Integer() {3}
' if the request is verified
If IPNResponse = "VERIFIED" Then
' check the receiver's e-mail (login is user's identifier in PayPal) and the transaction type
If Request("receiver_email") <> business Or Request("txn_type") <> "web_accept" Then
Try
' parameters are not correct. Write a response from PayPal and create a record in the Log file.
CreatePaymentResponses(Request("txn_id"), Convert.ToDecimal(Request("mc_gross"), provider), Request("payer_email"), Request("first_name"), Request("last_name"), Request("address_street"), Request("address_city"), Request("address_state"), Request("address_zip"), Request("address_country"), Convert.ToInt32(Request("custom")), False, "INVALID paymetn's parameters (receiver_email or txn_type)")
KBSoft.Carts.WriteFile("Error in payment_success: INVALID paymetn's parameters (receiver_email or txn_type)")
Catch ex As Exception
KBSoft.Carts.WriteFile("Error in payment_success: " + ex.Message)
readStream.Close()
strResponse.Close()
End Try
Return
End If
' check whether this request was received earlier for its identifier
If IsDuplicateID(Request("txn_id")) Then
' the current request has been already processed. Write a response from PayPal and create a record in the Log file.
CreatePaymentResponses(Request("txn_id"), Convert.ToDecimal(Request("mc_gross"), provider), Request("payer_email"), Request("first_name"), Request("last_name"), Request("address_street"), Request("address_city"), Request("address_state"), Request("address_zip"), Request("address_country"), Convert.ToInt32(Request("custom")), False, "Duplicate txn_id found")
KBSoft.Carts.WriteFile("Error in payment_success: Duplicate txn_id found")
readStream.Close()
strResponse.Close()
Return
End If
' the amount of payment, the status of the payment, amd a possible reason of delay
' The fact that Getting txn_type=web_accept or txn_type=subscr_payment are got odes not mean that seller will receive the payment.
' That's why we check payment_status=completed. The single exception is when the seller's account in not American and pending_reason=intl
If Request("mc_gross").ToString(ci) <> amount Or Request("mc_currency") <> currency_code Or (Request("payment_status") <> "Completed" And Request("pending_reason") <> "intl") Then
' parameters are incorrect or the payment was delayed. A response from PayPal should not be written to DB of an XML file
' because it may lead to a failure of uniqueness check of the request identifier.
' Create a record in the Log file with information about the request.
KBSoft.Carts.WriteFile("Error in payment_success: INVALID paymetn's parameters. Request: " + strFormValues)
readStream.Close()
strResponse.Close()
Return
End If
Try
' write a response from PayPal
CreatePaymentResponses(Request("txn_id"), Convert.ToDecimal(Request("mc_gross"), provider), Request("payer_email"), Request("first_name"), Request("last_name"), Request("address_street"), Request("address_city"), Request("address_state"), Request("address_zip"), Request("address_country"), Convert.ToInt32(Request("custom")), True, "")
KBSoft.Carts.WriteFile("Success in payment_success: PaymentResponses created")
'''''''''''''
' Here we notify the person responsible for goods delivery that
' the payment was performed and providing him with all needed information about
' the payment. Some flags informing that user paid for a services can be also set here.
' For example, if user paid for registartion on the site, then the flag should be set
' allowing the user who paid to access the site
'''''''''''''
Catch ex As Exception
KBSoft.Carts.WriteFile("Error in payment_success: " + ex.Message)
End Try
Else
KBSoft.Carts.WriteFile("Error in payment_success. IPNResponse = 'INVALID'")
End If
End While
readStream.Close()
strResponse.Close()
End Sub
''' <summary>
''' creating a record about the response to the payment request
''' </summary>
''' <param name="txn_id">A unique transaction number</param>
''' <param name="payment_price">The total cost of the cart</param>
''' <param name="email">buyer's email</param>
''' <param name="first_name">buyer's name</param>
''' <param name="last_name">buyer's last name</param>
''' <param name="street">buyer's street</param>
''' <param name="city">buyer's city</param>
''' <param name="state">buyer's state</param>
''' <param name="zip">buyer's ZIP</param>
''' <param name="country">buyer's country</param>
''' <param name="request_id">an identifier of the payment request</param>
''' <param name="is_success">a flag indicating whether the payment was successfully performed</param>
''' <param name="reason_fault">a possible reason of the payment failure</param>
Public Sub CreatePaymentResponses(ByVal txn_id As String, ByVal payment_price As Decimal, ByVal email As String, ByVal first_name As String, ByVal last_name As String, ByVal street As String, ByVal city As String, ByVal state As String, ByVal zip As String, ByVal country As String, ByVal request_id As Integer, ByVal is_success As Boolean, ByVal reason_fault As String)
Try
Dim ci As CultureInfo = New CultureInfo("en-us")
Dim xmlFile As String = Server.MapPath("~/App_Data/PaymentResponses.xml")
Dim doc As New XmlDocument()
Dim payment_id As Integer
Dim reader As XmlTextReader
If File.Exists(xmlFile) Then
reader = New XmlTextReader(xmlFile)
reader.Read()
Else
KBSoft.Carts.CreateXml(xmlFile, "Responses")
reader = New XmlTextReader(xmlFile)
reader.Read()
End If
doc.Load(reader)
reader.Close()
' getting a unique identifier of the payment_id payment
Dim nodes As XmlNodeList = doc.GetElementsByTagName("Request")
If nodes.Count <> 0 Then
payment_id = KBSoft.Carts.GetIdentity(nodes, "payment_id")
Else
payment_id = 0
End If
' creating a new element containing information about the payment
Dim myresponse As XmlElement = doc.CreateElement("Request")
myresponse.SetAttribute("payment_id", payment_id)
myresponse.SetAttribute("txn_id", txn_id)
myresponse.SetAttribute("payment_date", DateTime.Now.ToString(ci))
myresponse.SetAttribute("payment_price", payment_price.ToString(ci))
myresponse.SetAttribute("email", email)
myresponse.SetAttribute("first_name", first_name)
myresponse.SetAttribute("last_name", last_name)
myresponse.SetAttribute("street", street)
myresponse.SetAttribute("city", city)
myresponse.SetAttribute("state", state)
myresponse.SetAttribute("zip", zip)
myresponse.SetAttribute("country", country)
myresponse.SetAttribute("request_id", request_id)
myresponse.SetAttribute("is_success", is_success)
myresponse.SetAttribute("reason_fault", reason_fault)
doc.DocumentElement.AppendChild(myresponse)
doc.Save(xmlFile)
Catch ex As Exception
KBSoft.Carts.WriteFile("Error in payment_success.CreatePaymentResponses(): " + ex.Message)
End Try
End Sub
''' <summary>
''' getting a cart identifier for the identifier of the current request_id request
''' </summary>
''' <param name="request_id">the request identifier</param>
''' <returns>the identifier of the cart for the current request</returns>
Public Shared Function GetIDCart(ByVal request_id As String) As String
Try
Dim expression As String
expression = "request_id = '" + request_id + "'"
Dim tempRow As DataRow() = requests.Tables(0).Select(expression)
If tempRow.Length = 1 Then
Return tempRow(0).Item("cart_id").ToString
End If
Catch ex As Exception
KBSoft.Carts.WriteFile("Error in payment_success.GetIDCart(): " + ex.Message)
End Try
Return ""
End Function
''' <summary>
''' getting the total cost for an identifier of the current request_id request
''' </summary>
''' <param name="request_id">the request identifier</param>
''' <returns>the total cost of the identifier</returns>
Public Shared Function GetRequestPrice(ByVal request_id As String) As String
Try
Dim expression As String
expression = "request_id = '" + request_id + "'"
Dim tempRow As DataRow() = requests.Tables(0).Select(expression)
If tempRow.Length = 1 Then
Return tempRow(0).Item("price").ToString
End If
Catch ex As Exception
KBSoft.Carts.WriteFile("Error in payment_success.GetRequestPrice(): " + ex.Message)
End Try
Return ""
End Function
''' <summary>
''' checking whether the current request is duplicated for the unique number of the txn_id transaction
''' </summary>
''' <param name="txn_id">the unique transaction number</param>
''' <returns>true if the current request has already been processed</returns>
Public Function IsDuplicateID(ByVal txn_id As String) As Boolean
Try
Dim expression As String
expression = "txn_id = '" + txn_id + "'"
Dim tempRow As DataRow() = responses.Tables(0).Select(expression)
If tempRow.Length = 0 Then
Return False
End If
Return True
Catch ex As Exception
KBSoft.Carts.WriteFile("Error in payment_success.IsDuplicateID(): " + ex.Message)
Return False
End Try
End Function
End Class
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