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<!DOCTYPE html>
<html>
<head>
<title>Taler's "Demo" Shop: Choose payment method</title>
<script>
/*
@licstart The following is the entire license notice for the
JavaScript code in this page.
Copyright (C) 2014,2015 GNUnet e.V.
The JavaScript code in this page is free software: you can
redistribute it and/or modify it under the terms of the GNU
Lesser General Public License (GNU LGPL) as published by the
Free Software
Foundation, either version 3 of the License, or (at your option)
any later version. The code is distributed WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU LGPL for more details.
As additional permission under GNU LGPL version 3 section 7, you
may distribute non-source (e.g., minimized or compacted) forms of
that code without the copy of the GNU LGPL normally required by
section 4, provided you include this license notice and a URL
through which recipients can access the Corresponding Source.
@licend The above is the entire license notice
for the JavaScript code in this page.
*/
</script>
</head>
<body onload="signal_me()">
<!--
This page's main aim is to show to the customer all the accepted
payments methods and actually implementing just Taler; technically
the steps are:
1. retrieve the information about the donation from the
form and remember it in a PHP session
2. show a menu with all the required payments system options,
only showing "Taler" if the wallet is present
3. (JavaScript) implement the "checkout" button for Taler,
for the demo we ignore the other payment options.
-->
<?php
// get the donation information from form
$donation_receiver = $_POST['donation_receiver'];
$donation_amount = $_POST['donation_amount'];
$donation_currency = $_POST['donation_currency'];
// get frational part
list ($donation_value, $donation_fraction) = split ("\.", $donation_amount, 2);
// create PHP session and store donation information in session
$donation_fraction = (float) ("0." . $donation_fraction);
session_start();
$_SESSION['receiver'] = $donation_receiver;
$_SESSION['amount_value'] = (int) $donation_amount;
$_SESSION['amount_fraction'] = (int) ($donation_fraction * 1000000);
$_SESSION['currency'] = $donation_currency;
?>
<h2>Select your payment option</h2>
<div>
This is an example for a "checkout" page of a Web shop.
On the previous page, you have created the shopping cart
and decided which product to buy (i.e. which project to
donate KUDOS to). Now in this page, you are asked to
select a payment option. As Taler is not yet universally
used, we expect merchants will offer various payment options.
<p>
The page also demonstrates how to only enable (or show) the Taler
option if Taler is actually supported by the browser. For example,
if you disable the Taler extension now, the Taler payment option
will be disabled in the page. Naturally, you could also trivially
hide the Taler option entirely by changing the visibility instead.
<p>
Note that you MUST select Taler here for the demo to continue,
as the other payment options are just placeholders and not
really working in the demonstration. Also, it is of course
possible to ask the user to make this choice already on the
previous page (with the shopping cart), we just separated the
two steps to keep each step as simple as possible.
</div>
<form name="tform" action="" method="POST">
<div id="opt-form" align="left"><br>
<input type="radio" name="payment_system" value="lisa"
id="lisa-radio-button-id">Lisa</input>
<br>
<input type="radio" name="payment_system" value="ycard">You Card</input>
<br>
<input type="radio" name="payment_system" value="cardme">Card Me</input>
<br>
<input type="radio" name="payment_system" value="taler"
id="taler-radio-button-id" disabled="true">Taler</input>
<br>
<input type="button" onclick="pay(this.form)" value="Ok">
</div>
</form>
<script type="text/javascript">
/* This function is called from "taler_pay" after
we downloaded the JSON contract from the merchant.
We now need to pass it to the extension. */
function handle_contract(json_contract)
{
var cEvent = new CustomEvent('taler-contract', { detail: json_contract });
document.body.dispatchEvent(cEvent);
};
/* Trigger Taler contract generation on the server, and pass the
contract to the extension once we got it. */
function taler_pay(form)
{
var contract_request = new XMLHttpRequest();
/* Note that the URL we give here is specific to the Demo-shop
and not required by the protocol: each web shop can
have its own way of generating and transmitting the
contract, there just must be a way to get the contract
and to pass it to the wallet when the user selects 'Pay'. */
contract_request.open("GET", "/generate_taler_contract.php", true);
contract_request.onload = function (e)
{
if (contract_request.readyState == 4)
{
if (contract_request.status == 200)
{
/* display contract_requestificate (i.e. it sends the JSON string
to the extension) alert (contract_request.responseText); */
handle_contract(contract_request.responseText);
}
else
{
/* There was an error obtaining the contract from the merchant,
obviously this should not happen. To keep it simple, we just
alert the user to the error. */
alert("Failure to download contract from merchant " +
"(" + contract_request.status + "):\n" +
contract_request.responseText);
}
}
};
contract_request.onerror = function (e)
{
/* There was an error obtaining the contract from the merchant,
obviously this should not happen. To keep it simple, we just
alert the user to the error. */
alert("Failure requesting the contract:\n" + contract_request.statusText);
};
contract_request.send(null);
}
/* This function is called when the user presses the
'Ok' button. We are now supposed to trigger the
"corret" payment system logic. For this demo, we
only handle "taler". */
function pay(form)
{
for (var cnt=0; cnt < form.payment_system.length; cnt++)
{
var choice = form.payment_system[cnt];
if (choice.checked)
{
if (choice.value == "taler")
{
taler_pay(form);
}
else
{
alert(choice.value + ": NOT available in this demo!");
}
}
}
};
/* The following event gets fired whenever a customer has a Taler
wallet installed in his browser. In that case, the webmaster can decide
whether or not to display/enable Taler as a payment option in the dialog. */
function has_taler_wallet_cb(aEvent)
{
// enable the Taler payment option from the form
var tbutton = document.getElementById("taler-radio-button-id");
tbutton.removeAttribute("disabled");
tbutton.setAttribute("checked", "true");
};
/* Function called when the Taler extension was unloaded;
here we disable the Taler option and check "Lisa", as
some "valid" option should always be selected. */
function taler_wallet_unload_cb(aEvent)
{
var tbutton = document.getElementById("taler-radio-button-id");
tbutton.setAttribute("disabled", "true");
var lbutton = document.getElementById("lisa-radio-button-id");
lbutton.setAttribute("checked", "true");
};
/* The merchant signals its taler-friendlyness to the wallet,
thereby causing the wallet to make itself more visible in the menu. */
function signal_me()
{
var eve = new Event('taler-checkout-probe');
document.body.dispatchEvent(eve);
};
// function included to be run to test the page despite a
// wallet not being present in the browser. Enables the
// Taler option. NOT needed in real deployments.
function test_without_wallet(){
var tbutton = document.getElementById("taler-radio-button-id");
tbutton.removeAttribute("disabled");
};
// /////////////// Main logic run on load ////////////////////////
// Register event to be triggered by the wallet as a response to our
// first event
document.body.addEventListener("taler-wallet-present",
has_taler_wallet_cb,
false);
// event awaited by the wallet to change its button's color
// var eve = new Event('taler-payment-mfirst');
// document.body.dispatchEvent(eve);
// Register event to be triggered by the wallet when it gets enabled while
// the user is on the payment page
document.body.addEventListener("taler-load",
signal_me,
false);
// Register event to be triggered by the wallet when it is unloaded
document.body.addEventListener("taler-unload",
taler_wallet_unload_cb,
false);
</script>
</body>
</html>
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