How to return/export only data showing on screen in custom post type view all screen

Question

If I for example filter my custom post type by date and it only shows 2 records on screen, I only want to export those 2 records, but it is exporting a bunch of records out of my control ie: the wrong records.

How can I modify this to only export what is showing up on screen ie: the 2 records in this case?

add_action( 'init', 'func_export_some_records' );
function func_export_all_posts() {
    if(isset($_GET['export_some_records'])) {
        $arg = array(
                'post_type' => 'shirts',
                'fields' => 'ids'
            );


        global $post;
        $arr_post = get_posts($arg);
        if ($arr_post) {

            header("Content-Description: File Transfer");
            header("Content-Type: application/csv");
            header('Content-Disposition: attachment; filename="wp.csv"');
            header('Pragma: no-cache');
            header('Expires: 0');

            $file = fopen('php://output', 'w');

            fputcsv($file, array('COLUMN ONE', 'COLUMN TWO'));

            foreach ($arr_post as $post) {

                $color = get_post_meta( $post, 'user-color', true );
                $size = get_post_meta( $post, 'user-size', true );

                fputcsv($file, array($color, $size));
            }


            fclose($file);

        }
    }
}

Here is the button that triggers the download:

add_action( 'manage_posts_extra_tablenav', 'admin_post_list_top_export_button', 20, 1 );
function admin_post_list_top_export_button( $which ) {
    global $typenow;

    if ( 'shirts' === $typenow && 'top' === $which ) {
        ?>
        <input type="submit" name="export_some_records" id="export_some_records" class="button button-primary" value="Export Some Records" />
        <?php
    }

}

One way I thought of but not actually sure how to achieve is to get all the post ID's currently on screen and then in my $arg array use 'includes' => 'post id here'

Answer 1

<?php
//edit.php?s&post_status=all&post_type=shirts&action=-1&m=0&slug=03-02-2020&filter_action=Filter&paged=1&action2=-1 
//$parse_uri = explode('wp-content', $_SERVER['SCRIPT_FILENAME']);
//require_once($parse_uri[0] . 'wp-load.php');
header("Content-Description: File Transfer");
header("Content-Type: application/csv");
header('Content-Disposition: attachment; filename="wp.csv"');
header('Pragma: no-cache');
header('Expires: 0');

global $post;

//https://developer.wordpress.org/reference/classes/wp_query/
$post_status = isset($_REQUEST['post_status']) && $_REQUEST['post_status']=='all' ? 'any' : 'publish';
$date = explode('-',$_REQUEST['slug']);
$posts_per_page = $_REQUEST['action2'];
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;

$arg = array(
    'post_type' => $_REQUEST['post_type'],
    'post_status' => $post_status,
    'posts_per_page' => $posts_per_page,
    'paged' => $paged,
    'date_query' => array(
        'column' => 'post_date',
        'year' => $date[2],
        'month' => $date[1],
        'day' => $date[0],
    )
);

$posts = new WP_Query($arg);

if($posts->have_posts()){

    $file = fopen('php://output', 'w');

    fputcsv($file, array('COLUMN ONE', 'COLUMN TWO'));


    while ( $posts->have_posts() ){
        $posts->the_post();

        $color = get_post_meta( $post->ID, 'user-color', true );
        $size = get_post_meta( $post->ID, 'user-size', true );

        fputcsv($file, array($color, $size));
    }

    fclose($file);

}
?>

Answer 2

Create a file (csv.php) at the root of your template and to test, change the IDs.
Then run the code by accessing the URL:
//www.your_domain/wp-content/themes/your_template/csv.php

<?php
header("Content-Description: File Transfer");
header("Content-Type: application/csv");
header('Content-Disposition: attachment; filename="wp.csv"');
header('Pragma: no-cache');
header('Expires: 0');

$parse_uri = explode('wp-content', $_SERVER['SCRIPT_FILENAME']);
require_once($parse_uri[0] . 'wp-load.php');

$color = '';
$size = '';

$post_ids = array('68251','68159');

$args = array(
    'post_type' => 'shirts',
    'nopaging' => true,
    'post_status' => 'any',
    'include' => $post_ids,
);

$posts = get_posts($args);

if($posts){

    $file = fopen('php://output', 'w');

    fputcsv($file,array('COLUMN ONE','COLUMN TWO'));

    foreach ($posts as $post){

        $color = get_post_meta( $post->ID, 'user-color', true );
        $size = get_post_meta( $post->ID, 'user-size', true );

        fputcsv($file,array($color,$size));
    }

    fclose($file);

}
?>