Show Express Checkout button previews in editor

changelog/fix-show-preview-for-express-checkout-buttons-in-editor

@@ -0,0 +1,4 @@
+Significance: minor
+Type: fix
+
+Show Express Checkout button previews in template editor

client/tokenized-express-checkout/blocks/components/express-checkout-button-preview.js

@@ -0,0 +1,137 @@
+/**
+ * External dependencies
+ */
+import { useEffect, useRef } from 'react';
+
+/**
+ * Internal dependencies
+ */
+import { getExpressCheckoutButtonAppearance } from '../../utils';
+
+export const SUPPORTED_PREVIEW_PAYMENT_METHODS = [ 'googlePay', 'applePay' ];
+
+const GooglePayButtonPreview = ( { options, buttonAttributes, theme } ) => {
+	const googlePlayContainerRef = useRef( null );
+	const hasStartedLoadingGooglePlayButton = useRef( null );
+	const appearance = getExpressCheckoutButtonAppearance( buttonAttributes );
+	const borderRadius = appearance.variables.borderRadius;
+
+	useEffect( () => {
+		if (
+			googlePlayContainerRef.current &&
+			! hasStartedLoadingGooglePlayButton.current
+		) {
+			hasStartedLoadingGooglePlayButton.current = true;
+			( async () => {
+				// The container may be inside an iframe, so we need to retrieve a reference to the document and window objects.
+				const targetDocument =
+					googlePlayContainerRef.current.ownerDocument;
+				const targetWindow = targetDocument.defaultView;
+				if ( ! targetWindow.google?.payments?.api?.PaymentsClient ) {
+					await new Promise( ( resolve ) => {
+						const script = document.createElement( 'script' );
+						script.src = 'https://pay.google.com/gp/p/js/pay.js';
+						script.onload = resolve;
+						targetDocument.head.appendChild( script );
+					} );
+				}
+
+				const googlePayClient = new targetWindow.google.payments.api.PaymentsClient(
+					{
+						environment: 'TEST',
+					}
+				);
+
+				const buttonColor = theme === 'black' ? 'black' : 'white'; // There is no 'outline' theme in Google Pay.
+
+				const button = googlePayClient.createButton( {
+					buttonType: options.buttonType.googlePay,
+					buttonColor,
+					buttonRadius: parseFloat( borderRadius ),
+					buttonSizeMode: 'fill',
+					onClick: () => {},
+				} );
+				googlePlayContainerRef.current.appendChild( button );
+			} )();
+		}
+	}, [ theme, borderRadius, options.buttonType.googlePay ] );
+
+	useEffect( () => {
+		googlePlayContainerRef.current
+			?.querySelector( 'button' )
+			?.style?.setProperty( 'border-radius', borderRadius );
+	}, [ borderRadius ] );
+
+	return (
+		<div
+			ref={ googlePlayContainerRef }
+			id="express-checkout-button-preview-googlePay"
+			style={ {
+				height: `${ options.buttonHeight }px`,
+				width: '100%',
+			} }
+		/>
+	);
+};
+
+const ApplePayButtonPreview = ( { options, buttonAttributes, theme } ) => {
+	const appearance = getExpressCheckoutButtonAppearance( buttonAttributes );
+	const borderRadius = appearance.variables.borderRadius;
+
+	const buttonStyle = {
+		height: `${ options.buttonHeight }px`,
+		borderRadius,
+		ApplePayButtonType: options.buttonType.applePay,
+		WebkitAppearance: '-apple-pay-button',
+		width: '100%',
+	};
+
+	if ( [ 'black', 'white', 'white-outline' ].includes( theme ) ) {
+		buttonStyle.ApplePayButtonStyle = theme;
+	} else {
+		buttonStyle.ApplePayButtonStyle = 'white';
+	}
+
+	return (
+		<div>
+			<button
+				type="button"
+				id="express-checkout-button-preview-applePay"
+				className="express-checkout-button-preview"
+				style={ buttonStyle }
+			/>
+		</div>
+	);
+};
+
+const ExpressCheckoutButtonPreview = ( {
+	expressPaymentMethod,
+	options,
+	buttonAttributes,
+} ) => {
+	const theme = options.buttonTheme[ expressPaymentMethod ];
+
+	if ( expressPaymentMethod === 'googlePay' ) {
+		return (
+			<GooglePayButtonPreview
+				options={ options }
+				buttonAttributes={ buttonAttributes }
+				theme={ theme }
+			/>
+		);
+	}
+
+	if ( expressPaymentMethod === 'applePay' ) {
+		return (
+			<ApplePayButtonPreview
+				options={ options }
+				buttonAttributes={ buttonAttributes }
+				theme={ theme }
+			/>
+		);
+	}
+
+	return null;
+};
+
+export default ExpressCheckoutButtonPreview;

client/tokenized-express-checkout/blocks/components/express-checkout-component.js

@@ -11,6 +11,9 @@ import {
 } from '../../event-handlers';
 import { useExpressCheckout } from '../hooks/use-express-checkout';
 import { PAYMENT_METHOD_NAME_EXPRESS_CHECKOUT_ELEMENT } from 'wcpay/checkout/constants';
+import ExpressCheckoutButtonPreview, {
+	SUPPORTED_PREVIEW_PAYMENT_METHODS,
+} from './express-checkout-button-preview';
 
 const getPaymentMethodsOverride = ( enabledPaymentMethod ) => {
 	const allDisabled = {
@@ -131,16 +134,28 @@ const ExpressCheckoutComponent = ( {
 		};
 	};
 
+	const checkoutElementOptions = {
+		...withBlockOverride(),
+		...adjustButtonHeights( withBlockOverride(), expressPaymentMethod ),
+		...getPaymentMethodsOverride( expressPaymentMethod ),
+	};
+
+	if (
+		isPreview &&
+		SUPPORTED_PREVIEW_PAYMENT_METHODS.includes( expressPaymentMethod )
+	) {
+		return (
+			<ExpressCheckoutButtonPreview
+				expressPaymentMethod={ expressPaymentMethod }
+				buttonAttributes={ buttonAttributes }
+				options={ checkoutElementOptions }
+			/>
+		);
+	}
+
 	return (
 		<ExpressCheckoutElement
-			options={ {
-				...withBlockOverride(),
-				...adjustButtonHeights(
-					withBlockOverride(),
-					expressPaymentMethod
-				),
-				...getPaymentMethodsOverride( expressPaymentMethod ),
-			} }
+			options={ checkoutElementOptions }
 			onClick={ onClickHandler }
 			onConfirm={ onConfirm }
 			onReady={ onElementsReady }

client/tokenized-express-checkout/blocks/express-checkout-element.scss

@@ -21,3 +21,11 @@
 	margin-left: 1px !important;
 	width: 99% !important;
 }
+
+// Preview button
+@supports not ( -webkit-appearance: -apple-pay-button ) {
+	/* stylelint-disable-next-line selector-id-pattern */
+	#express-payment-method-woocommerce_payments_express_checkout_applePay:has( #express-checkout-button-preview-applePay ) {
+		display: none;
+	}
+}