X-Cart forums

[Ed B.]

Hi, I am making a new thread not to mess up the other one, but they are related.

So, I have been trying to build on the model of Tony's demo payment module.
We need to pass more information from the cart to gateway, notably the first, last name, the e-mail of the client, as well as the amount of payment. If I understand correctly, it should boil down to rewriting
the function.

getFormFields()

All my trials failed, and as a desperate attempt, I tried to put

  protected function getFormFields()
    {
        return array(
            'transactionID' => $this->transaction->getPublicTxnId(),
            'returnURL' => $this->getReturnURL('transactionID'),
      'x_first_name'    => $this->getProfile()->getBillingAddress()->getFirstname(),
    'x_last_name'     => $this->getProfile()->getBillingAddress()->getLastname(),
    'amount'=>300,
   );
    }

and, to my surprise, I discovered that I couldn't redeploy
the store

I thought it was forbidden to pass a "constant" value from x-cart to gateway this way because there were better ways to do it, but it still
intrigued me, and I changed the line

    'amount'=>300,

to

 'useless_variable'=>300,

and then the cart passes correctly 'useless_variable' to the gateway

Thus, here is my question. Are there forbidden key name for the array that getFormFields() return? Is there a list of such key names?