NWJS Version : 0.30.2
Operating System : MacOS
Dialog for PaymentRequest API should show up when calling request.show() for the supported browser - in this case, latest Chromium version (request is an PaymentRequest object)
Error in console: DOMException: Request cancelled
Sample code:
<!DOCTYPE html>
<html>
<head>
<title>Payment app</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<pre id="output"></pre>
<script>
var methodData = [
{
supportedMethods: ['basic-card'],
data: {
supportedNetworks: ['visa', 'mastercard', 'amex'],
supportedTypes: ['credit']
}
}
];
var details = {
displayItems: [
{
label: "Sub-total",
amount: { currency: "USD", value : "100.00" }, // US$100.00
}
],
total: {
label: "Total due",
amount: { currency: "USD", value : "100.00" }, // US$109.00
}
};
var options = {
requestShipping: false
};
var request=new PaymentRequest(methodData, details, options);
request.show().then(console.log).catch(console.err);
</script>
</body>
</html>
Error:

I can reproduce this issue on Linux/Windows/Mac with nwjs-sdk-v0.30.2. The dialog doesn't popup, and DOMException: Request cancelled is displayed in the console.
This is fixed in git and will be available in the next nightly build.