PayPal and MVC

Recently i had an opportunity to implement paypal. At first it was way too overwhelming to read about it and implement it in a day or two. However, this video link  by Rob Conery cleared up lot of my confusion. I recommend seeing this video if you have any plans to implement paypal. So, PayPal SandBox  is the development site where you can test your code. All the code i have implemented is either in documentation or from the video.

//Controller

public class PayPalController : Controller
{
private const string Server_URL = "https://www.sandbox.paypal.com/cgi-bin/webscr?";


public PayPalController()
{

}

public ActionResult Index()
{
MovieModel movieModel = new MovieModel();
movieModel.MovieDate = new List() {
new DateTime(2011,9,15).ToLongDateString()
};
movieModel.MovieTime = new List()
{
"12:00 PM","3:00 PM","7:00 PM","10:00 PM"
};
movieModel.NoOfTickets = new List() {1,2,3,4,5,6};
movieModel.Price = 15;
return View(movieModel);
}

public RedirectResult PostToPayPal(MovieModel movieModel)
{
string custom = GetTransactionFromDB(movieModel);
string cmd = "_xclick";
string business = "SELLEREMAIL";
string notify_url = "Localhost/PayPal/IPN";
int amount = movieModel.Price;
string item_name = "Ticket";
string redirect = string.Format("{0}&cmd={1}¬ify_url={2}&amount={3}&item_name={4}&custom={5}&business={6}",Server_URL,cmd,notify_url,amount,item_name,custom,business);
return Redirect(redirect);  
}

private string GetTransactionFromDB(MovieModel movieModel)
{
//store from model in DB and return transactionID
//store amount also,need to verify later.
return "123-234-5678";
}


public void IPN()
{
var formVals = new Dictionary();
formVals.Add("cmd", "_notify-validate");
string response = GetPayPalResponse(formVals, true);
if (response == "VERIFIED")
{
string sAmountPaid = Request["mc_gross"];
string paymentStatus = Request["payment_status"];
string customField = Request["custom"];
if (sAmountPaid == GetPriceFromDatabase(id) && paymentStatus == "Completed")
{
string buyerEmail = Request["payer_email"];
string transactionID = Request["txn_id"];//PayPal Transaction ID(Store It)
string firstName = Request["first_name"];
string lastName = Request["last_name"];
//Call to SP saying Payment Processed
}
else
{
//Call to SP Saying Payment Corrupt or Invalid
}
}
else if (response == "INVALID")
{
//Call to SP Saying Payment Failed;
}
else
{
//Send Email to Admin with response details
}
}

private string GetPriceFromDatabase(string id)
{
return "15";
}



public string GetPayPalResponse(Dictionary formVals, bool useSandbox)
{

string paypalUrl = useSandbox ? "https://www.sandbox.paypal.com/cgi-bin/webscr"
: "https://www.paypal.com/cgi-bin/webscr";


HttpWebRequest req = (HttpWebRequest)WebRequest.Create(paypalUrl);

// Set values for the request back

req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";

byte[] param = Request.BinaryRead(Request.ContentLength);
string strRequest = Encoding.ASCII.GetString(param);

StringBuilder sb = new StringBuilder();
sb.Append(strRequest);

foreach (string key in formVals.Keys)
{
sb.AppendFormat("&{0}={1}", key, formVals[key]);
}
strRequest += sb.ToString();
req.ContentLength = strRequest.Length;

string response = "";
using (StreamWriter streamOut = new StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII))
{

streamOut.Write(strRequest);
streamOut.Close();
using (StreamReader streamIn = new StreamReader(req.GetResponse().GetResponseStream()))
{
response = streamIn.ReadToEnd();
}
}

return response;
}


}
}

//View

<% using (Html.BeginForm("PostToPayPal", "PayPal", new { id= "Form" }))
   { %>
(Theatre Name)
Date: <%= Html.DropDownListFor(model => model.MovieDate,new SelectList(Model.MovieDate,Model.MovieDate.First())) %> 
<%= Html.HiddenFor(model => model.Price, new { id = "Price" })%>
<%= Html.HiddenFor(model => model.TheatreName, new { id = "TheatreName"}) %>




   
Time
   
Tickets
         
Price
         
Buy With PayPal
  
   
<%= Html.DropDownListFor(model => model.MovieTime, new SelectList(Model.MovieTime, "3:00 PM"))%>
   


<%= Html.DropDownListFor(model => model.NoOfTickets, new SelectList(Model.NoOfTickets, 1), new { id = "Tickets" })%>
         


15$
 






 
 
<%} %>

Email me if you have questions. But like i said, the video has most of the explanation.