Overriding template with hooks - php

Question

I am having a little trouble editing a Woocommerce template with hooks. Essentially I would just like to change the product-image template so instead of linking to the uploaded product image, it links to the product post.
The current product-image.php woocommerce template has
global $post, $woocommerce, $product;
?>
<div class="images">
<?php
if ( has_post_thumbnail() ) {
$image_title = esc_attr( get_the_title( get_post_thumbnail_id() ) );
$image_link = wp_get_attachment_url( get_post_thumbnail_id() );
$image = get_the_post_thumbnail( $post->ID, apply_filters( 'single_product_large_thumbnail_size', 'shop_single' ), array(
'title' => $image_title
) );
$attachment_count = count( $product->get_gallery_attachment_ids() );
if ( $attachment_count > 0 ) {
$gallery = '[product-gallery]';
} else {
$gallery = '';
}
echo apply_filters( 'woocommerce_single_product_image_html', sprintf( '%s', $image_link, $image_title, $image ), $post->ID );
} else {
echo apply_filters( 'woocommerce_single_product_image_html', sprintf( '<img src="%s" alt="Placeholder" />', woocommerce_placeholder_img_src() ), $post->ID );
}
?>
<?php do_action( 'woocommerce_product_thumbnails' ); ?>
</div>
I am unsure of how to adapt the echo apply_filters( 'woocommerce_single_product_image_html', sprintf( '%s', $image_link, $image_title, $image ), $post->ID ); to change the %s to a link to the post.
The hook I am using is:
add_action('woocommerce_product_thumbnails', 'custom_links');
function custom_links() {
//code
}
Could someone help me gain some direction with this?

Answer 1

You are calling action not filter. Also you are calling the wrong one.
Change this:
add_action('woocommerce_product_thumbnails', 'custom_links');
to this:
add_filter('woocommerce_single_product_image_html', 'custom_links', 10, 2);
The 2 represents the argument count for the function and your custom_links() should be something like:
function custom_links($link, $post_id) {
$pattern = '/(?<=href=")([^"]*)/';
$replacement = get_permalink($post->ID);
return preg_replace($pattern, $replacement, $link);
}
Process the $link variable as needed and then return it.