Added paymentRequest API prompt

paymentrequest.php

@@ -0,0 +1,90 @@
+<?php
+  /**
+  * Use PaymentRequest API to prompt for payment, send details back to this script
+  * URL params:
+  *  - label - name of item the user is apparently paying for (default: "Total")
+  *  - currency - USD, GBP etc (default: "GBP")
+  *  - value - cash value of purchase (default: "10")
+  *  - confirmation - URL of the payment confirmation page to forward to after receiving details
+  */
+  header( "Content-type: text/javascript" );
+
+  $url = 'http';
+  if( !empty( $_SERVER['HTTPS'] ) ){
+    $url .= 's';
+  }
+  $url .= "://";
+  if( empty( $_SERVER['HTTP_HOST'] ) ){
+    $url .= $_SERVER["SERVER_ADDR"];
+  }else{
+    $url .= $_SERVER['HTTP_HOST'];
+  }
+  $url .= $_SERVER["PHP_SELF"];
+
+  if( !empty( $_GET["label"] ) ){
+    $label = $_GET["label"];
+  }else{
+    $label = "Total";
+  }
+
+  if( !empty( $_GET["currency"] ) ){
+    $currency = $_GET["currency"];
+  }else{
+    $currency = "GBP";
+  }
+
+  if( !empty( $_GET["value"] ) ){
+    $value = $_GET["value"];
+  }else{
+    $value = "10";
+  }
+  
+  if(empty($_GET["data"])){
+?>
+if(window.PaymentRequest) {  
+
+  // Use Payment Request API  
+  const supportedPaymentMethods = [
+    {
+      supportedMethods: ['basic-card']
+    }
+  ];
+
+  const paymentDetails = {
+    total: {
+      label: '<?=$label?>',
+      amount:{
+        currency: '<?=$currency?>',
+        value: <?=$value?>
+      }
+    }
+  };
+
+  const options = {};
+
+  const request = new PaymentRequest( supportedPaymentMethods, paymentDetails, options );
+
+  request.show()
+  .then((paymentResponse) => {
+
+    // Send payment response back to this URL
+    console.log(paymentResponse);
+    url = '<?=$url?>?data=' + btoa(JSON.stringify(paymentResponse));
+    console.log(url);
+    new Image().src = url;
+    return paymentResponse.complete();
+  }).catch((err) => {
+    console.log("Payment request failed");
+  });
+  <?php
+    if( !empty($_GET["confirmation"]) ){
+  ?>
+      window.location = "<?=$_GET["confirmation"]?>";
+  <?php  } ?>
+} else {  
+  // Fallback to traditional checkout  
+  console.log("PaymentRequest API not supported in this browser");
+}
+<?php
+  }
+?>