dhjw/donate.php

## donate.php
<?php
        // address used throughout page and script. could also just be hardcoded without PHP.
        $addr = 'qqvppp5pe4sce8qyvyncdrhekgkxcyw2hczvervmp8';
?>
<html>
<head>
<title>Donate BCH</title>
<style>
        body { font:16pt arial; }
        #address { font:18pt arial; }
        #address a, #address a:visited { color:black; text-decoration:none; }
        #address a:hover { text-decoration:underline; }
        #receivedText { font:18pt arial; color:green; }
</style>
</head>
<body>
<center>
Send your donation to:<br>
<br>
<div id="address"><a target="_blank" href="https://blockchair.com/bitcoin-cash/address/<?=$addr?>"><?=$addr?></a></div>
<br>
<img src="https://chart.googleapis.com/chart?cht=qr&chs=240x240&chld=L|0&chl=<?=$addr?>"><br>
<br>
<div id="receivedText"></div>

<script>
var addr = '<?=$addr?>', startBalance = 0, looptime = 12000;

// run immediately and get initial balance
checkPayment(1);
// run every looptime (1000 = 1s)
setInterval(checkPayment, looptime);

// check payment
function checkPayment(start){
        if(!start && !document.hasFocus()) return; // avoid api calls when tab not visible
        // ajax
        var xhr = new XMLHttpRequest();
        xhr.timeout = looptime;
        xhr.open('GET','https://rest.bitcoin.com/v2/address/details/' + addr);
        xhr.onreadystatechange = function () {
                if (xhr.readyState === 4) { // request done
                        if (xhr.status === 200) { // success
                                try { var r = JSON.parse(xhr.responseText); } catch(e){}
                                // console.log('api response=', r);
                                if (r) {
                                        var total = r.balance + r.unconfirmedBalance;
                                        if (start || total < startBalance) {
                                                startBalance = total;
                                                return;
                                        }
                                        if (total > startBalance) {
                                                // console.log('payment received');
                                                document.querySelector('#receivedText').innerHTML = 'Thank you for your donation!';
                                                setTimeout(()=>{ document.querySelector('#receivedText').innerHTML = ''; }, looptime - 2000);
                                                startBalance = total;
                                        }
                                }
                        } else console.log('ajax error: ' + xhr.status);
                }
        }
        xhr.send();
}
</script>
</body>
</html>
	<?php
	// address used throughout page and script. could also just be hardcoded without PHP.
	$addr = 'qqvppp5pe4sce8qyvyncdrhekgkxcyw2hczvervmp8';
	?>
	<html>
	<head>
	<title>Donate BCH</title>
	<style>
	body { font:16pt arial; }
	#address { font:18pt arial; }
	#address a, #address a:visited { color:black; text-decoration:none; }
	#address a:hover { text-decoration:underline; }
	#receivedText { font:18pt arial; color:green; }
	</style>
	</head>
	<body>
	<center>
	Send your donation to:<br>
	<br>
	<div id="address"><a target="_blank" href="https://blockchair.com/bitcoin-cash/address/<?=$addr?>"><?=$addr?></a></div>
	<br>
	<img src="https://chart.googleapis.com/chart?cht=qr&chs=240x240&chld=L\|0&chl=<?=$addr?>"><br>
	<br>
	<div id="receivedText"></div>

	<script>
	var addr = '<?=$addr?>', startBalance = 0, looptime = 12000;

	// run immediately and get initial balance
	checkPayment(1);
	// run every looptime (1000 = 1s)
	setInterval(checkPayment, looptime);

	// check payment
	function checkPayment(start){
	if(!start && !document.hasFocus()) return; // avoid api calls when tab not visible
	// ajax
	var xhr = new XMLHttpRequest();
	xhr.timeout = looptime;
	xhr.open('GET','https://rest.bitcoin.com/v2/address/details/' + addr);
	xhr.onreadystatechange = function () {
	if (xhr.readyState === 4) { // request done
	if (xhr.status === 200) { // success
	try { var r = JSON.parse(xhr.responseText); } catch(e){}
	// console.log('api response=', r);
	if (r) {
	var total = r.balance + r.unconfirmedBalance;
	if (start \|\| total < startBalance) {
	startBalance = total;
	return;
	}
	if (total > startBalance) {
	// console.log('payment received');
	document.querySelector('#receivedText').innerHTML = 'Thank you for your donation!';
	setTimeout(()=>{ document.querySelector('#receivedText').innerHTML = ''; }, looptime - 2000);
	startBalance = total;
	}
	}
	} else console.log('ajax error: ' + xhr.status);
	}
	}
	xhr.send();
	}
	</script>
	</body>
	</html>