Search product by multiple SKU in wordpress admin

This small plugin provide the functionality to add a button to upload CSV and then search the products by sku which are in first column of csv.

<?php
 /* 
  Plugin Name: Multiple SKU Search in CSV
  Plugin URI: https://www.tektalkpals.com/
  Description: Add search by multiple sku with csv upload
  Author: Tektalkpals
  Version: 0.1.0
  Author URI: https://www.tektalkpals.com/
  Text Domain: multiple-sku-search
  Domain Path: /languages/

  License:
  Released under the GPL license
  http://www.gnu.org/copyleft/gpl.html
  Copyright 2018 
 */
if ( ! defined( 'ABSPATH' ) ) {
  exit; // Exit if accessed directly.
}

/**
 * Load text-domain of plugin
 */
load_plugin_textdomain( 'multiple-sku-search', false, dirname( plugin_basename( __FILE__ ) ) . '/languages/' );
$post_type = 'product';
  /* hook my code */
  add_action( 'restrict_manage_posts', 'mss_add_filter_to_product_list');
  add_filter( 'parse_query', 'mss_filter_posts_by_multiple_sku');
  add_action('admin_footer','mss_sku_csv_upload_callback',10);

  function mss_add_filter_to_product_list(){
    $post_type = isset($_GET['post_type'])?$_GET['post_type']:'product';
    if ('product' == $post_type){ ?> 
      <input type="button" name="sku_csv" id="sku_csv" value="Upload SKU CSV to search" class="button">
      <input type="hidden" name="sku_csv_id" id="sku_csv_id">
      <?php
    }
  }

  function mss_sku_csv_upload_callback(){?>
  <script type="text/javascript">
    jQuery(document).ready(function(){
      $('#sku_csv').click(function(e) {
          e.preventDefault();
          var csv = wp.media({ 
              title: 'Upload CSV',
              multiple: false // mutiple: true if you want to upload multiple files at once
          }).open()
          .on('select', function(e){
              // This will return the selected file from the Media Up-loader, the result is an object
              var uploaded_csv = csv.state().get('selection').first();
              // We convert uploaded file to a JSON object to make accessing it easier
              var csv_id = uploaded_csv.toJSON().id;
              $('#sku_csv_id').val(csv_id);
          });
      });
    });
  </script>
  <?php
  }

  function mss_filter_posts_by_multiple_sku($query){
    global $pagenow;
    $post_type = isset($_GET['post_type'])?$_GET['post_type']:'product';
    $sku_csv_id = isset($_GET['sku_csv_id'])?$_GET['sku_csv_id']:'';
    if ( ('product'==$post_type) && is_admin() && ($pagenow=='edit.php') && ($sku_csv_id != '')) {
      $sku_strings = mss_read_sku_csv($sku_csv_id);
      if($sku_strings!=''){
        $query->query_vars['meta_key'] = '_sku';
        $query->query_vars['meta_value'] = $sku_strings;
        $query->query_vars['meta_compare'] = 'IN';  
      }
    }
  }

  function mss_read_sku_csv($sku_csv_id){
    $file_path = get_attached_file( $sku_csv_id );
    $sku_string = '';
    if( file_exists($file_path) ){  /// check CSV file exists
      $handle = fopen("$file_path", 'r');
      $counter = 0;
      while ( ($data = fgetcsv($handle)) !== FALSE ) {
        if($counter == 0){ /// read csv headers
          $counter++;
          continue;
        }
        $counter++;
        $sku_string .=  ($counter==1)?'':',';
        $sku_string .= $data[0];
      }
    }
    return $sku_string;
  }

Create a folder by name ‘multiple-sku-search’ under plugins directory of wordpress site. In this folder create a file ‘multiple-sku-search.php’ and copy-paste the above code in this file.

Now activate the plugin in wordpress site admin, It will add a button on woocommerce product listing panel to choose csv file. On choosing a csv file click on filter button there. It will show the desired results…