Injecting content with $wp_query->current_post restarts from zero on paged pages. How to inject content after X posts, regardless of pagination?

Question

I am creating a shortcode that outputs a custom loop. Within the loop while, I am injecting certain content after a particular post count. This is done by checking the current_post number. This particular function is quite long (and filled with commented-out code, from testing).

Here is a link to my current version (currently with ALL posts on a single page): https://gist.github.com/Garconis/c93ce89c3d378bfb7f5d8df97acbebc2

This works fine if/when ALL posts (posts_per_page => -1) are showing, but as soon as I add pagination (e.g., set posts_per_page => 5, the injected content is starting from a count of 0 on each new page.

How can I update this, to be able to inject my specific content after X posts, without the count starting over with each new page?

Bare bones of what I have:

<?php
// create shortcode to list all Featured Itineraries
add_shortcode( 'fs_burn_homepage_loop','fs_all_featured_itineraries_shortcode' );
function fs_all_featured_itineraries_shortcode( $atts ) {
ob_start();
// Query posts from the database.
$options = array(
    // Arguments for your query.
    'post_type'         => array('post', 'ajde_events'),
    'posts_per_page'    => 5,
    'paged'             => 1,
);

/* To get the Easy Load More plugin to work */
if ( get_query_var( 'paged' ) ) { 
    $options['paged'] = get_query_var( 'paged' ); 
} 
elseif ( get_query_var( 'page' ) ) { 
    $options['paged'] = get_query_var( 'page' ); 
} else { 
    $options['paged'] = 1; 
}

$query = new WP_Query( $options );
// Check that we have query results
if ( $query->have_posts() ) {

    // we have posts, so lets wrap them
    echo'<div id="fs-homepage-loop" class="fs-all-posts">';

        // Start looping over the query results.
        while ( $query->have_posts() ) {

            // Set up post data.
            $query->the_post(); 

            echo '<article id="post-'. get_the_ID() .'" class="fs-post-article '. join( ' ', get_post_class() ) .'">
                <div class="fs-post-content-wrapper">
                    <div class="fs-post-name">
                        <h2 class="entry-title"><a href="'. get_permalink(); .'">'. get_the_title() .'</a></h2>
                    </div>
                </div>
            </article>';

            // inject stuff after X posts
            if( ($query->current_post == 3) ) {
                echo '<article class="fs-post-article">
                    <div class="fs-post-content-wrapper">
                        content after post 4 is here
                    </div>
                </article>';
            }
            if( ($query->current_post == 9) ) {
                echo '<article class="fs-post-article">
                    <div class="fs-post-content-wrapper">
                        content after post 10 is here
                    </div>
                </article>';
            }

        // close the loop WHILE
        }

        wp_reset_postdata();

    // close post wrapper
    echo '</div>';

    //function for the Easy Load More plugin
    load_more_button();

    $myvariable = ob_get_clean();

    return $myvariable;

// close the query IF
}
// ELSE it cant find ANY posts that match
else {
    echo '<div class="fs-no-posts-found"><h4>We currently have no stories to show you.</h4></div>';
// close the query ELSE */
}
}

Would it be as simple as somehow checking the current_post count AND the page number of the pagination? Since I supposedly know how many posts would show per page...

Answer 1

For the record, I just found a new/different way to accomplish this goal. It's not quite the same, but it does allow me to insert a new post type after every X posts in my original loop.

This is the source: https://www.gowp.com/blog/inserting-custom-posts-loop/

The method was done via the code below, which essentially injects a new custom post type into the loop, and it seems to work regardless of the pagination.

add_action( 'wp', 'fs_only_do_on_homepage' );
function fs_only_do_on_homepage() {

if( is_front_page() ) {

    /* change the query to inject ads after every X frequency */
    // https://www.gowp.com/blog/inserting-custom-posts-loop/

    add_filter( 'the_posts', 'fs_insert_ads', 10, 2 );
    function fs_insert_ads( $posts, $query ) {

        // We don't want our filter to affect post lists in the admin dashboard
        if ( is_admin() ) return $posts;

        // We also only want our filter to affect the main query
        if ( ! is_main_query() ) return $posts;

        // Set a variable for the frequency of the insertion which we'll use in some math later on
        $freq = 2;

        /* Retrieve the ads, and calculate the posts_per_page on the fly, 
         * based on the value from the original/main query AND our frequency
         * this helps ensure that the inserted posts stay in sync regardless of pagination settings
         */
        $args = array(
            'post_type'         => 'fs_ads',
            'posts_per_page'    => floor( $query->query_vars['posts_per_page'] / $freq ),
            'paged'             => ( $query->query_vars['paged'] ) ? $query->query_vars['paged'] : 1,
            'orderby'           => 'menu_order',
            'order'             => 'ASC',
            'meta_key'          => 'status',
            'meta_value'        => 'enable',
        );

        // inserts the ads into the $posts array, using array_slice() ... and do some math to ensure they are inserted correctly
        if ( $fs_ads = get_posts( $args ) ) {
            $insert = -1;
            foreach ( $fs_ads as $fs_ad ) {
                $insert =  $insert + ( $freq + 1 );
                array_splice( $posts, $insert, 0, array( $fs_ad ) );
            }
        }

        return $posts;
    } // end the fs_insert_ads function

} // end checking is_home

} // end the fs_only_do_on_homepage function

I do lose the ability to say which item goes between which post, but it does achieve my original goal of trying to inject a custom post type into my loop, after every X number of posts.