Run a function on custom button click in woocommerce admin order page

Question

Based on "Add a button on top of admin orders list in woocommerce" answer code, I was able to add a custom button on woocommerce admin orders list.

Here is that code (lightly customized):

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

    if ( 'shop_order' === $typenow && 'top' === $which ) {
        ?>
        <div class="alignleft actions custom">
            <button type="submit" name="custom_" style="height:32px;" class="button" value=""><?php
                echo __( 'Import Couriers', 'woocommerce' ); ?></button>
        </div>
        <?php
    }
}

Now I need to run a the following function when this custom button is clicked:

function update_shipping_couriers_meta_field() {
    $dir = __DIR__;
    $couriers = file( $dir . '/import-couriers.csv', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES );
    $count = count(couriers);
    $i = 1;

    do {
        if ( !empty( $couriers ) ) {
            foreach ( $couriers as $a ) {
                if ( !empty( $a ) ) {
                    $rows = explode(';', $a);

                    $id = $rows[0];
                    $id = int($id);
                    $couriers = $rows[1];

                    update_post_meta( $id, '_shipping_couriers', $couriers );
                }
                $i++;
            }
        }
    } 
    while ( $i <= $count );
}

In practice, the function updates a "_shipping_couriers" custom field based on a specific order ID. The two values ​​are present in a csv file.

I've already tested it and it's working. I "just" have it run when I click on the button I created with the function above.

How can I run my function when the button is clicked?

Answer 1

There are some missing things in your code and an error in your last function where count(couriers); need to be instead count($couriers);.

// Display an action button in admin order list header
add_action( 'manage_posts_extra_tablenav', 'admin_order_list_top_bar_button', 20, 1 );
function admin_order_list_top_bar_button( $which ) {
    global $pagenow, $typenow;

    if ( 'shop_order' === $typenow && 'edit.php' === $pagenow && 'top' === $which ) {
        ?>
        <div class="alignleft actions custom">
            <button type="submit" name="import_courier" style="height:32px;" class="button" value="yes"><?php
                echo __( 'Import Couriers', 'woocommerce' ); ?></button>
        </div>
        <?php
    }
}

// Trigger an action (or run some code) when the button is pressed
add_action( 'restrict_manage_posts', 'display_admin_shop_order_language_filter' );
function display_admin_shop_order_language_filter() {
    global $pagenow, $typenow;

    if ( 'shop_order' === $typenow && 'edit.php' === $pagenow &&
    isset($_GET['import_courier']) && $_GET['import_courier'] === 'yes' ) {
        
        ## -------- The code to be trigered -------- ##
        
        update_shipping_couriers_meta_field();
        
        ## -------------- End of code -------------- ##
    }
}

// Your function that will be triggered on button press
function update_shipping_couriers_meta_field() {
    $dir = __DIR__;
    $couriers = file( $dir . '/import-couriers.csv', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES );
    $count = count($couriers);
    $i = 1;
    
    do {
        if ( ! empty( $couriers ) ) {
            foreach ( $couriers as $a ) {
                if ( ! empty( $a ) ) {
                    $rows = explode(';', $a);
    
                    update_post_meta( intval($rows[0]), '_shipping_couriers', $rows[1] );
                }
                $i++;
            }
        }
    } 
    while ( $i <= $count );
}

Code goes in functions.php file of your active child theme (or active theme). Tested and works.

Based from: Add a button on top of admin orders list in woocommerce