Created a shortcode, using it twice (but differently) on a page but its just outputting the same one twice

Question

I have created a little shortcode that allows a user to output a custom post type contents into another page: [module name="foo"]

On a given page I have:

[module name="foo"]
[module name="bar"]

However what is output is just foo twice.

The relevant code:

<?php 

// ASSUMING [module name="some-slug"]
function cpt_shortcode( $atts ){
    $a = shortcode_atts( array(
        'name' => 'something else',
    ), $atts );

    if( false === ( $shortcode_post = get_transient( 'shortcode_post' ) ) ) {

        $shortcode_post = new WP_Query( array(
            'post_type'     => 'module',
            'name'          => $a['name']
        ));
        set_transient( 'shortcode_post', $shortcode_post, 60*60*4 );

    }
        if ($shortcode_post->have_posts())
            while ($shortcode_post->have_posts()):
                $shortcode_post->the_post();

                // WHICH MODULE
                $moduleType = get_field('module_type');
                if($moduleType == 'basic'){
                    include('module-basic.php');
                } elseif($moduleType == 'cta'){
                    include('module-cta.php');
                } elseif($moduleType == 'grid'){
                    include('module-grid.php');
                } elseif($moduleType == 'carousel'){
                    include('module-carousel.php');
                }
            endwhile;
        else
            $out = "No modules match your shortcode";
        wp_reset_query();


    return html_entity_decode($out);

}
add_shortcode( 'module', 'cpt_shortcode' );


// KILL THE SHORTCODE TRANSIENT WHEN A NEW POST IS SAVED
function shortcode_delete_its_transients() {
        delete_transient( 'shortcode_post' );
}

add_action( 'save_post', 'shortcode_delete_its_transients' );

Here is the gist.

Answer 1

You're using it twice differently, but you're not creating a unique transient name, so the second time the shortcode runs it just uses whatever was saved in the transient the first time the shortcode ran.

Come up with some way to uniquely identify the transient, like:

set_transient( 'shortcode_post_' . sanitize_key( $a['name'] ), $shortcode_post, 60*60*4 );

That said, I don't know that there's really much advantage to saving that result to a transient at all.