Limit WooCommerce Sold Products Display Quantity

dgtepro-limit-sold-products.php

<?php

/*
 * Plugin Name: Limit Sold Products
 * Description: Limits the number of sold out products that show up on the front end of your WooCommerce store 
 * Author: Andy Gee
 * Author URI: https://dgte.pro
 * Version: 1.0
 * Plugin Slug: dgtepro-limit-sold-products
 */
if (!defined('ABSPATH')) {
  die("Nope.");
}

// Add settings to WooCommerce settings page
add_filter('woocommerce_get_settings_products', 'limit_sold_products_settings', 10, 1);
function limit_sold_products_settings($settings) {
  if (isset($_GET['section']) && $_GET['section'] == 'advanced') {
    $settings[] = array(
      'name'     => __('Limit Sold Products', 'woocommerce'),
      'desc'     => __('Limit the number of sold out products that show up on the front end of your WooCommerce store', 'woocommerce'),
      'id'       => 'limit_sold_products_settings',
      'type'     => 'title',
      'desc_tip' => true,
    );

    $settings[] = array(
      'name' => __('Enable', 'woocommerce'),
      'id'   => 'limit_sold_products_enable',
      'type' => 'checkbox',
    );

    $settings[] = array(
      'name' => __('Percentage', 'woocommerce'),
      'id'   => 'limit_sold_products_percentage',
      'type' => 'number',
      'min'  => 0,
      'max'  => 100,
      'step' => 1,
      'custom_attributes' => array(
        'style' => 'width: 50px;',
      ),
    );

    $settings[] = array(
      'type' => 'sectionend',
      'id'   => 'limit_sold_products_settings',
    );
  }
  return $settings;
}

// Add settings link to plugin page
add_filter('plugin_action_links', 'my_plugin_settings_link', 10, 2);

function my_plugin_settings_link($links, $file) {
  // Check if the current plugin is yours
  if ($file == 'dgtepro-limit-sold-products/dgtepro-limit-sold-products.php') {
    // Add the settings link
    $settings_link = '<a href="' . admin_url('admin.php?page=wc-settings&tab=products&section=advanced') . '">' . __('Settings', 'dgtepro-limit-sold-products') . '</a>';
    array_push($links, $settings_link);
  }
  return $links;
}



function limit_sold_out_products_quantity($q) {

  if (!is_admin() && !isset($q->query_vars['sold_out_limited']) && (isset($q->query_vars['product_cat']) || $q->get('post_type') == 'product') || is_page(wc_get_page_id('shop'))) {
    // Get the plugin settings
    $enabled = get_option('limit_sold_products_enable', 'no');
    $percentage = get_option('limit_sold_products_percentage', '10');

    if ($enabled == 'yes') {
      $q->query_vars['sold_out_limited'] = true;

      // Query all the in stock products based on current query
      $in_stock_args = $q->query_vars;
      $out_of_stock_args = $q->query_vars;
      $in_stock_args['meta_query'][] = array(
        'key' => '_stock_status',
        'value' => 'instock',
        'operator' => 'IN'
      );
      $in_stock_query = new WP_Query($in_stock_args);
      $in_stock_posts = $in_stock_query->get_posts();
      $in_stock_count = count($in_stock_posts);

      // Query all the out of stock products based on current query
      $out_of_stock_args = $q->query_vars;
      $out_of_stock_args['meta_query'][] = array(
        'key' => '_stock_status',
        'value' => 'outofstock',
        'operator' => 'IN'
      );
      $out_of_stock_query = new WP_Query($out_of_stock_args);
      $out_of_stock_posts = $out_of_stock_query->get_posts();

      // Limit the number of out of sstock products to 10% of the in stock products count.

      $limited_out_of_stock_posts = array_slice($out_of_stock_posts, 0, ceil($in_stock_count * ($percentage / 100)));

      // Merge the limited_out_of_stock_posts and in_stock_posts products
      $final_posts = array_merge($limited_out_of_stock_posts, $in_stock_posts);

      // Modify the main query to get posts based on the IDs of the merged set of products
      $q->set('post__in', wp_list_pluck($final_posts, 'ID'));
      $q->set('orderby', 'post__in');
    }
  }
}
add_action('pre_get_posts', 'limit_sold_out_products_quantity', 999, 2);



// Add the settings page to the WooCommerce settings menu
function lsp_add_settings_page() {
  add_filter('woocommerce_settings_tabs_array', 'lsp_add_settings_tab', 50);
  add_action('woocommerce_settings_tabs_lsp_settings', 'lsp_settings_tab_content');
  add_action('woocommerce_update_options_lsp_settings', 'lsp_save_settings');
}
add_action('admin_init', 'lsp_add_settings_page');


function lsp_add_settings_tab($settings_tabs) {
  $settings_tabs['lsp_settings'] = __('Limit Sold Products', 'lsp');
  return $settings_tabs;
}

function lsp_settings_tab_content() {
  woocommerce_admin_fields(lsp_get_settings());
}

function lsp_save_settings() {
  woocommerce_update_options(lsp_get_settings());
}

function lsp_get_settings() {
  $settings = array(
    'section_title' => array(
      'name' => __('Limit Sold Products Settings', 'lsp'),
      'type' => 'title',
      'desc' => '',
      'id' => 'lsp_settings_section_title'
    ),
    'enabled' => array(
      'name' => __('Enabled', 'lsp'),
      'type' => 'checkbox',
      'desc' => __('Check to enable limiting of sold products', 'lsp'),
      'id' => 'lsp_enabled'
    ),
    'percentage' => array(
      'name' => __('Percentage', 'lsp'),
      'type' => 'range',
      'desc' => __('Select the percentage of sold out products to display (0-50)', 'lsp'),
      'id' => 'lsp_percentage',
      'css' => 'width: 50%',
      'default' => '10',
      'desc_tip' => true,
      'attributes' => array(
        'min' => '0',
        'max' => '50',
        'step' => '1',
      )
    ),
    'section_end' => array(
      'type' => 'sectionend',
      'id' => 'lsp_settings_section_end'
    )
  );
  return apply_filters('lsp_settings', $settings);
}

This added a settings page to WooCommerce > Settings > Products > Advanced. There's a checkbox to enable/disable the functionality and a percentage input field to limit the percentage of sold products that are displayed in categories and main shop page on the front end.

A settings of 10 (10%) will do the following on any category.

• Fetch all in-stock products for the current query (category or shop).
• Count the fetched products and calculate 10% of those from settings.
• Fetch that count quantity of out-of-stock products for the current query.
• Merge the IDs for those two lists of products.
• Alter the original query to fetch products based on those IDs (to maintain original sorting, pagination etc)