Image Shortcode from ACF ID

Question

I would like to create a shortcode that displays the image from an ACF custom field which currently has the return format set to the Image ID. The shortcode needs to accept a post_id so it can get the field from a certain page.

So the shortcode would be:

[acf_featured_item post_id="88"]

I am aware that there is an ACF shortcode available, but there is already another location which is dependant on the return format as ID. So I cannot change this.

My Current code is:

function acf_featured_item_shortcode( $atts ) {
// Attributes
$atts = shortcode_atts(
    array(
        'post_id' => '',
    ),
    $atts
);
$image = get_field('featured_item', $post_id );
$size = 'medium'; // (thumbnail, medium, large, full or custom size)
if( $image ) {
$output = wp_get_attachment_image( $image, $size, "", array( "class" => "mx-auto d-block" ));
} 
return $output;
}
add_shortcode( 'acf_featured_item', 'acf_featured_item_shortcode' );

But this only works when you are on the page for that id. How do I get this shortcode to work on any page with any post_id input?

Answer 1

It's because you have forgot to use $atts['post_id'] please find below code.

function acf_featured_item_shortcode( $atts ) {
    // Attributes
    $atts = shortcode_atts(
        array(
            'post_id' => '',
        ),
        $atts
    );
    $post_id = $atts['post_id'];
    $image = get_field('featured_item', $post_id );
    $size = 'medium'; // (thumbnail, medium, large, full or custom size)
    if( $image ) {
        $output = wp_get_attachment_image( $image, $size, "", array( "class" => "mx-auto d-block" ));
    } 
    return $output;
}
add_shortcode( 'acf_featured_item', 'acf_featured_item_shortcode' );