Set featured image from acf image field from ACF block

• emmigereb

• February 5, 2024 at 5:22 am

I created an ACF block which has an image field.
The field is registered with php like this and it is working fine:

		[
			'key' => 'field_cpt_case_header_img',
			'name' => 'cpt_case_header_img',
			'label' => esc_html__( 'Representetive image', 'wptheme' ),
			'type' => 'image',
			'required' => '1',
			'preview_image' => 'thumbnail',
		],

And I have this function to save the image field as featured image:

function case_set_featured_image( $post_id ) {
	if ( get_post_type( $post_id ) !== 'case' ) {
		return;
	}

	$acf_image = get_field( 'cpt_case_header_img', $post_id );

	if ( $acf_image ) {
		// Attempt to set ACF image as the featured image
		$result = update_post_meta( $post_id, '_thumbnail_id', $acf_image['ID'] );
		$featured_image_id = get_post_thumbnail_id( $post_id );
	}
}
add_action( 'save_post', 'case_set_featured_image' );

But no featured image is saved, it is empty.

• emmigereb

• February 12, 2024 at 5:11 pm

I have this on another site not using ablock editor and works just fine:

function acf_set_featured_image( $value, $post_id, $field ) {
	if ( '' !== $value ) {
		//Add the value which is the image ID to the _thumbnail_id meta data for the current post
		update_post_meta( $post_id, '_thumbnail_id', $value );
	}
	return $value;
}
add_filter( 'acf/update_value/name=hero_image_slideshow_single_image', 'acf_set_featured_image', 10, 3 );