1.2. Frontend Rendering

frontend-rendering.php

<?php
register_block_type( 'rave/initiative-tracker', array(
    'editor_script'   => 'initiative-tracker-editor-script',
    'editor_style'    => 'initiative-tracker-editor-style',
    'style'           => 'initiative-tracker-style',
    'render_callback' => __NAMESPACE__ . '\render_block',
) );

function render_block( array $attributes ) : string {
    $id    = $attributes['id'];
    $class = 'wp-block-rave-initiative-tracker';

    ob_start();
    ?>

    <div
        class="<?php echo esc_attr( $class ); ?>"
        data-id="<?php echo esc_attr( $id ); ?>"
        data-post_id="<?php echo esc_attr( get_the_ID() ); ?>"
    >
        <!-- Your actual block content here... -->
    </div>

    <?php
    return ob_get_clean();
}