Can I Use Braintree.js With A .NET Web Application

Question

So I've been looking into Braintree Payments for a couple of days now. I love the architecture, concept, etc. After looking through the documentation and the .NET walk-throughs I've noticed that all of the examples for .NET are in MVC3. I am trying to integrate Braintree into my current .NET Web Application using regular web forms.

My goal is to have a normal web form post back to the payment page with both customer data and card data. The card data should be encrypted using their Braintree.js. That way I can send everything over to Braintree for processing including the encrypted card data.

The form would look something like this:

<p>
  <label>Card Number</label>
  <asp:TextBox ID="number" AutoCompleteType="Disabled" MaxLength="20" Width="150" data-encrypted-name="number" runat="server" />        
</p>
<p>
  <label>CVV</label>
  <asp:TextBox ID="cvv" AutoCompleteType="Disabled" MaxLength="4" Width="50" data-encrypted-name="cvv" runat="server" />
</p>
<p>
  <label>Expiration (MM/YYYY)</label>
  <asp:TextBox ID="month" AutoCompleteType="Disabled" MaxLength="2" data-encrypted-name="month" runat="server" />
 /
  <asp:TextBox ID="year" AutoCompleteType="Disabled" MaxLength="4" data-encrypted-name="year" runat="server" />
</p>
<asp:Button ID="btnSubmit" Text="SUBMIT" runat="server" />

<script type="text/javascript" src="https://js.braintreegateway.com/v1/braintree.js"></script>
<script type="text/javascript">
  var braintree = Braintree.create("MyClientSideKey");
  braintree.onSubmitEncryptForm('braintree-payment-form');
</script>

Then in the code-behind I would set the Form.Action, Form.Method and Form.ID as follows:

protected void Page_Load(object sender, EventArgs e)
{
  Form.Action = "CreateTransaction()";
  Form.Method = "POST";
  Form.ID = "braintree-payment-form";  
}

So then hopefully when the user submits the form it hits the "CreateTransaction()" member along with the encrypted card data in the "collection" parameter like this:

[HttpPost]
public ActionResult CreateTransaction(FormCollection collection)
{
  TransactionRequest request = new TransactionRequest
  {
    Amount = 1000.0M,
    CreditCard = new TransactionCreditCardRequest
  {
  Number = collection["number"],
  CVV = collection["cvv"],
  ExpirationMonth = collection["month"],
  ExpirationYear = collection["year"]
  },
  Options = new TransactionOptionsRequest
  {
    SubmitForSettlement = true
  }
};

Result<Transaction> result = Constants.Gateway.Transaction.Sale(request);

return null;
}

When I take this approach the form never posts back to the "CreateTransaction()" member. What am I missing? Can this be done using regular old web forms?

Answer 1

OK, so after LOTS of experimenting and shooting in the dark for a bit I was able to get this the Braintree.js to encrypt the data before passing it to my server. From there I am able to us the code behind to handle the payment processing.

Here is the ASP.NET web form that I'm using:

Card Number

    <p>
        <label>CVV</label>
        <asp:TextBox ID="txtCVV" AutoCompleteType="Disabled" MaxLength="4" Width="50" data-encrypted-name="cvv" runat="server" />
    </p>
    <p>
        <label>Expiration (MM/YYYY)</label>
        <asp:TextBox ID="txtMonth" AutoCompleteType="Disabled" MaxLength="2" data-encrypted-name="month" runat="server" />
        /
        <asp:TextBox ID="txtYear" AutoCompleteType="Disabled" MaxLength="4" data-encrypted-name="year" runat="server" />
    </p>
    <asp:Button ID="btnSubmit" Text="SUBMIT" runat="server" />

    <script type="text/javascript" src="https://js.braintreegateway.com/v1/braintree.js"></script>
    <script type="text/javascript">
        var braintree = Braintree.create("YOURKEYHERE");
            braintree.onSubmitEncryptForm('braintree-payment-form');
    </script>

Please take note of a few key details here:

• I am using server controls. Not simple HTML tags.

• braintree.js will encrypt any field that has the "data-encrypted-name" attribute.

• The "data-encrypted-name" attribute does NOT need to be the same as the control's ID attribute.

• The braintree.js script is posting to the "braintree-payment-form" form.

So when I click Submit button this form will naturally post back. The particular form that I'm using has a master page, so I need to alter the Form.ID in the Page_Load:

protected void Page_Load(object sender, EventArgs e)
{
  //Adjust the properties of the form itself as this
  //form has a master page.         
  Form.ID = "braintree-payment-form";

  //Wire up the click event
  btnSubmit.Click += btnSubmit_Click;
}

In the click event handler I am then able to extract the encrypted values from the Request.Form object and then submit the transaction request to the Braintree Gateway:

void btnSubmit_Click(object sender, EventArgs e)
{
  //--------------------------------------------------------------------------------------------------
  //Extract encrypted values from the Request.Form object
  //braintree.js has encrypted these values before placing them in
  //the Request object.
  //--------------------------------------------------------------------------------------------------
  string number = Request.Form["number"].ToString();
  string cvv = Request.Form["cvv"].ToString();
  string month = Request.Form["month"].ToString();
  string year = Request.Form["year"].ToString();

  //--------------------------------------------------------------------------------------------------
  //Gateway
  //This is the Braintree Gateway that we will use to post the transaction
  //to.  This is included here in the example but should be extracted out
  //into some static class somewhere.  Possibly in another layer.
  //--------------------------------------------------------------------------------------------------
  BraintreeGateway Gateway = new BraintreeGateway
  {
    Environment = Braintree.Environment.SANDBOX,
    PublicKey = "YOURPUBLICKEYHERE",
    PrivateKey = "YOURPRIVATEKEYHERE",
    MerchantId = "YOURMERCHANTIDHERE"
  };

  //--------------------------------------------------------------------------------------------------
  //Transaction Request
  //This is the actual transaction request that we are posting to the 
  //Braintree gateway.  The values for number, cvv, month and year have 
  //been encrypted above using the braintree.js.  If you were to put a 
  //watch on the actual server controls their ".Text" property is blank
  //at this point in the process.
  //--------------------------------------------------------------------------------------------------
  TransactionRequest transactionRequest = new TransactionRequest
  {
    Amount = 100.00M,
    CreditCard = new TransactionCreditCardRequest
    {
      Number = number,
      CVV = cvv,
      ExpirationMonth = month,
      ExpirationYear = year,
    }
  };

  //--------------------------------------------------------------------------------------------------
  //Transaction Result
  //Here we are going to post our information, including the encrypted
  //values to Braintree.  
  //--------------------------------------------------------------------------------------------------
  Result<Transaction> result = Gateway.Transaction.Sale(transactionRequest);
}

OK, so this is a very basic example of how to post a transaction to Braintree. However it solves the first big hurdle that I have with getting the card data to be encrypted before it gets to my server. Hope this helps...