wp-search-replace-image-image-block-thumbnail-urls.php

<?php
/**
 * WP Search & Replace Image Block Thumbnail URLs
 *
 * Helpful after regenerating image thumbnails. Designed to run in a custom page template.
 * Note: limit get_posts() results if PHP times out.
 *
 * @author Eric Saner
 */

// Define image sizes
$image_sizes = ['small', 'medium', 'large'];

// Create empty array to store posts that will be updated
$updated_posts = [];

// Get all posts
$posts = get_posts([
    'post_type'     => 'post',
    'numberposts'   => -1
]);

// Loop through post content
foreach ($posts as $post) {
    // Continue if no content
    if (!$post->post_content) {
        continue;
    }

    // Get all image blocks from block comment to adjacent figure tag
    preg_match_all('/\s*<!-- wp:image[\s\S]+?<\/figure>/', $post->post_content, $images, PREG_SET_ORDER);

    // Continue if no image blocks
    if (!$images) {
        continue;
    }

    // Create empty search and replace arrays to store image URLs
    $search = [];
    $replace = [];

    // Loop through image blocks
    foreach ($images as $image) {
        // Isolate block comment
        preg_match('/\s*{[\s\S]+?}/', $image[0], $comment);

        // Continue if no comment
        if (!$comment) {
            continue;
        }

        // Convert block comment to json
        $image_data = json_decode($comment[0]);

        // Continue if no json data
        if (is_null($image_data) || !is_object($image_data)) {
            continue;
        }

        // Continue if no image ID, no sizeSlug, or image size is not a valid insertable size
        $no_image_id    = !isset($image_data->id);
        $no_image_size  = !isset($image_data->sizeSlug) || !in_array($image_data->sizeSlug, $image_sizes);

        if ($no_image_id || $no_image_size) {
            continue;
        }

        // Isolate image src attribute
        preg_match('/src="([^"]*)"/i', $image[0], $old_src);

        // Fill search and replace arrays with old and new image urls
        $search[]   = substr($old_src[0], 5, -1);
        $replace[]  = wp_get_attachment_image_url($image_data->id, $image_data->sizeSlug);
    }

    if ($search && $replace) {
        // Update post content with new image urls
        wp_update_post([
            'ID'            => $post->ID,
            'post_content'  => str_replace($search, $replace, $post->post_content)
        ]);

        // Add post to $updated_posts
        $updated_posts[] = $post;
    }
}
?>

<h2>Total Posts Updated: <?= count($updated_posts) ?></h2>

<?php
// Output list of updated posts
if ($updated_posts) {
    ?>

    <ul>

        <?php
        foreach($updated_posts as $p) {
            ?>

            <li><?= $p->post_title ?> | <a href="<?= get_the_permalink($p->ID) ?>"><?= $p->ID ?></a></li>

            <?php
        }
        ?>

    </ul>

    <?php
}