Creating a “repeater meta-box” without a Plugin in WordPress

WordPress Repeater MetaBox.php

<?php
add_action('admin_init', 'gpm_add_meta_boxes', 2);

function gpm_add_meta_boxes() {
    add_meta_box( 'gpminvoice-group', 'Custom Repeatable', 'Repeatable_meta_box_display', 'page', 'normal', 'default');
}

function Repeatable_meta_box_display() {
    global $post;
    $gpminvoice_group = get_post_meta($post->ID, 'customdata_group', true);
     wp_nonce_field( 'gpm_repeatable_meta_box_nonce', 'gpm_repeatable_meta_box_nonce' );
    ?>
    <script type="text/javascript">
    jQuery(document).ready(function( $ ){
        $( '#add-row' ).on('click', function() {
            var row = $( '.empty-row.screen-reader-text' ).clone(true);
            row.removeClass( 'empty-row screen-reader-text' );
            row.insertBefore( '#repeatable-fieldset-one tbody>tr:last' );
            return false;
        });

        $( '.remove-row' ).on('click', function() {
            $(this).parents('tr').remove();
            return false;
        });
    });
  </script>
  <table id="repeatable-fieldset-one" width="100%">
  <tbody>
    <?php
     if ( $gpminvoice_group ) :
      foreach ( $gpminvoice_group as $field ) {
    ?>
    <tr>
      <td width="15%">
        <input type="text"  placeholder="Title" name="TitleItem[]" value="<?php if($field['TitleItem'] != '') echo esc_attr( $field['TitleItem'] ); ?>" /></td> 
      <td width="70%">
      <textarea placeholder="Description" cols="55" rows="5" name="TitleDescription[]"> <?php if ($field['TitleDescription'] != '') echo esc_attr( $field['TitleDescription'] ); ?> </textarea></td>
      <td width="15%"><a class="button remove-row" href="#1">Remove</a></td>
    </tr>
    <?php
    }
    else :
    // show a blank one
    ?>
    <tr>
      <td> 
        <input type="text" placeholder="Title" title="Title" name="TitleItem[]" /></td>
      <td> 
          <textarea  placeholder="Description" name="TitleDescription[]" cols="55" rows="5">  </textarea>
          </td>
      <td><a class="button  cmb-remove-row-button button-disabled" href="#">Remove</a></td>
    </tr>
    <?php endif; ?>

    <!-- empty hidden one for jQuery -->
    <tr class="empty-row screen-reader-text">
      <td>
        <input type="text" placeholder="Title" name="TitleItem[]"/></td>
      <td>
          <textarea placeholder="Description" cols="55" rows="5" name="TitleDescription[]"></textarea>
          </td>
      <td><a class="button remove-row" href="#">Remove</a></td>
    </tr>
  </tbody>
</table>
<p><a id="add-row" class="button" href="#">Add another</a></p>
 <?php
}
add_action('save_post', 'custom_repeatable_meta_box_save');
function custom_repeatable_meta_box_save($post_id) {
    if ( ! isset( $_POST['gpm_repeatable_meta_box_nonce'] ) ||
    ! wp_verify_nonce( $_POST['gpm_repeatable_meta_box_nonce'], 'gpm_repeatable_meta_box_nonce' ) )
        return;

    if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE)
        return;

    if (!current_user_can('edit_post', $post_id))
        return;

    $old = get_post_meta($post_id, 'customdata_group', true);
    $new = array();
    $invoiceItems = $_POST['TitleItem'];
    $prices = $_POST['TitleDescription'];
     $count = count( $invoiceItems );
     for ( $i = 0; $i < $count; $i++ ) {
        if ( $invoiceItems[$i] != '' ) :
            $new[$i]['TitleItem'] = stripslashes( strip_tags( $invoiceItems[$i] ) );
             $new[$i]['TitleDescription'] = stripslashes( $prices[$i] ); // and however you want to sanitize
        endif;
    }
    if ( !empty( $new ) && $new != $old )
        update_post_meta( $post_id, 'customdata_group', $new );
    elseif ( empty($new) && $old )
        delete_post_meta( $post_id, 'customdata_group', $old );


}

thanks bro !
Data is not saved! How to save them as unserials.

It seems like you are mentioning that you've created repter code for an "without plugin", aligning with your business logic and client requirements. If you're looking for someone to connect with you or discuss your work, you might want to reach out through the provided website link (https://www.coderwolves.com/contact-us/).
**connct with skype ** https://join.skype.com/invite/w6QdOavrsO3i

If you have any specific questions or if there's something specific you'd like assistance with regarding your custom code or any related topic, feel free to provide more details, and I'll do my best to help within the scope of my capabilities.

this is copy pase code becasue gpm is clinet project . this is written by Me in last 10 yeare ago. i am added in stackflow profile. make your self logic

Hi @vinay123456 , Yes this was copied from stackovflow I guess. I used to use this code in many projects frequently. So I created this gist to find this code quickly. Obviously I was making self logic on top of this code.

Thanks for sharing this code block.

thanks bro !
Data is not saved! How to save them as unserials.

how to activate this hook to woocommerce product post ?

Hi, I am working to a different method which creates multiple separated strings of meta keys and related values.
I also studied your code, which is very interesting, but with the nonscalar array the result is serialized by WP.
Tested trying to add unserialize() or the wp maybe_unserialize() but it doesn't work. How do you extract and split data to be used in front-end? Query?

Well, since I have to insert into db a volume of more than 5000 data, I would have liked to avoid the laborious steps of print_r() and echo for each of the single meta_values ​​of the multidimensional array.. but since nobody here answers (apart from old mentions to xml that do not apply to me), I fear that nobody knows of a simpler alternative way .. Or it's a dormant conversation.

Thanks anyway, I'll get by.