Adds an action to the loop to display a [Buy at Acme] button containing the merchant's name to the WooCommerce Product Loop which links to an External/Affiliate product. [datafeedr]

add-merchant-name-to-button.php

<?php

/**
 * Adds an action to the loop to display a [Buy at Acme] button containing the merchant's name
 * to the WooCommerce Product Loop which links to an External/Affiliate product.
 */
function mycode_add_more_details_button_to_external_with_merchant_name() {
	add_action( 'woocommerce_after_shop_loop_item', 'mycode_display_more_details_button_to_external_with_merchant_name' );
}

add_action( 'init', 'mycode_add_more_details_button_to_external_with_merchant_name' );

/**
 * Display [Buy at Acme] button containing the merchant's name in the
 * WooCommerce Product Loop which links to an External/Affiliate product.
 *
 * @global WC_Product_External $product
 */
function mycode_display_more_details_button_to_external_with_merchant_name() {

	/**
	 * @var WC_Product_External $product
	 */
	global $product;

	if ( 'external' != $product->get_type() ) {
		return;
	}

	$url      = $product->get_product_url();
	$merchant = $product->get_attribute( 'pa_merchant' );
	$text     = $merchant ? sprintf( __( 'Buy at %s', 'mycode' ), $merchant ) : __( 'Buy Now', 'mycode' );
	$title    = sprintf( __( 'View more details about %s', 'mycode' ), $product->get_name() );
	$class    = sprintf( 'button add_to_cart_button product_type_%s', $product->get_type() );

	$format = '<a href="%1$s" title="%2$s" class="%3$s" target="_blank">%4$s</a>';

	printf( $format, esc_url( $url ), esc_attr( $title ), esc_attr( $class ), esc_html( $text ) );
}