Posting Data to Another URL

[PedroDePacos]

Hello,

I am developing an ASP.NET shopping cart that uses PayPal for payment processing. I would like to find a way to post the shopping cart variables to PayPal without displaying them in the URL.

I have been searching for hours without being able to find a solution to this question. It works fine when I pass the variables through the URL, but I don't want my customers to be able to see the variables that I'm passing to PayPal. I'd appreciate any help or advice.

[Arc]

Doesnt the Session object persist even when navigating out of the site you developed?

I would just store the values in the session.

[PedroDePacos]

Then how do I pass the session variables to PayPal, and how will PayPal process them?

[Arc]

I have no idea. How exactly do you expect paypal to take your variables? What exactly are you trying to do? I dont really understand. I assumed you were trying to fill in some fields on a paypal page or something...

[hellswraith]

Are you doing this in your form tag?
method="post"

Also, maybe paypal doesn't support this method. Maybe they only support querystring values (which is what you see in the address bar). You should check with them.

[PedroDePacos]

Sorry, if I wasn't clear earlier. I am just trying to send PayPal the information pertaining the my customer's shopping cart (such as item ID, name, quantity, price, etc.)

I can do it through the URL, but I don't want my customers to be able to see the variables (I don't want anyone trying to change the price or the quantities). I just need to know how to POST the variables without actually putting them in the URL.

[PedroDePacos]

PayPal does support the POST method as I have seen sites that do not use the querystring method to pass shopping cart variables to PayPal.

Can you explain using the Session variable method. I know what they are and how to implement them, but I don't get how storing my customer's shopping cart in session variables allows PayPal to use and process them.

[PedroDePacos]

Well,

I have figured out how to post the data to PayPal (without using the querystring method), but now how do I open the PayPal page for my customers?

Here is my code

            Dim strURL As String = "https://www.paypal.com/xclick/?"""

            Dim strRedirect As String = "cmd=_cart"
            strRedirect += "&business=" + Server.UrlEncode("[email protected]")
            strRedirect += "&invoice=" + Server.UrlEncode(10000) + "&item_name=AME Magazine&item_number=10003"

            Dim myWriter As StreamWriter
            Dim objRequest As HttpWebRequest = CType(WebRequest.Create(strURL), HttpWebRequest)
            objRequest.Method = "POST"
            objRequest.ContentLength = strRedirect.Length
            objRequest.ContentType = "application/x-www-form-urlencoded"
            Try

                myWriter = New StreamWriter(objRequest.GetRequestStream())
                myWriter.Write(strRedirect)
            Catch
                'error message
                Console.WriteLine(e.ToString)
            Finally
                myWriter.Close()
            End Try

            Dim objResponse As HttpWebResponse = CType(objRequest.GetResponse(), HttpWebResponse)
            Dim newsr As New StreamReader(objResponse.GetResponseStream())
            Dim respText As String = newsr.ReadToEnd()

respText returns the html of the PayPal page but I can't just response.write(respText) because the customer actually has to be redirected to the PayPal page in order for it to work properly.

[hellswraith]

Response.Redirect(respText)

[PedroDePacos]

response.redirect(respText) does not work because respText is not a URL, it is the HTML code from the PayPal page.

[hellswraith]

Try something like this. (it is from memory, may not be exact)

Dim myLitControl As New LiteralControl()
myLitControl.Text = respText
Me.Controls.Add(myLitControl)


You can also use a placeholder on your page, then add the literalcontrol tot hat placeholder I believe.

[robdotnet00]

Doesnt paypal have a webservice?

[PedroDePacos]

Thanks Hellswraith, but I know how to display the html string I get from PayPal, I wanted to know if there was a way that I could, not just display the page, but actually redirect my customers to the PayPal page after I POST the values.

As far as I know, robdotnet00, PayPal does not have a webservice.

Anyways, I solved this problem by developing another page that creates a custom form based on the customer's current shopping cart. This is just a regular html form that Posts the hidden variables to the PayPal site.

It's one more page that my customers will have to click through, but at least it works.