Woocommerce - Set Minimum quantity for products in cart

Restricting user to buy minimum quantity for products in woo-commerce is a pretty cool thing, we can achieve it by following the below steps

Step1:

1. Collect the product ids for which you wanted to restrict the quantity during checkout, store them in a array

<?php

$pd_min_quantity= array( 

array( 'id' => 3587, 'min' => 99),

array( 'id' => 2554, 'min' => 87),

array( 'id' => 5587, 'min' => 52),

array( 'id' => 4488, 'min' => 40),

       array( 'id' => 2555, 'min' => 80),

);

?>

Step2:

Add Following code to your themes - > functions.php

Note: don't forget to update your product ids and quantity 

<?php

add_action( 'woocommerce_check_cart_items', 'restrict_product_quantity' );

function restrict_product_quantity() {

if( is_cart() || is_checkout() ) {

global $woocommerce;

$pd_min_quantity= array(

array( 'id' => 3587, 'min' => 99),

array( 'id' => 2554, 'min' => 87),

array( 'id' => 5587, 'min' => 52),

array( 'id' => 4488, 'min' => 40),

       array( 'id' => 2555, 'min' => 80),

);

$i = 0;

$odd_prod = array();

foreach( $woocommerce->cart->cart_contents as $pd_cart ) {

foreach( $pd_min_quantity as $pd_quantity ) {

if( $pd_quantity['id'] == $pd_cart['product_id'] ) {

if( $pd_cart['quantity'] < $pd_quantity['min'] ) {

$odd_prod[$i]['id'] = $pd_cart['product_id'];

$odd_prod[$i]['in_cart'] = $pd_cart['quantity'];

$odd_prod[$i]['min_req'] = $pd_quantity['min'];

}

}

}

$i++;

}

if( is_array( $odd_prod) && count( $odd_prod ) > 1 ) {

$message = '<strong>Minimum quantity per product should be added.</strong><br />';

foreach( $odd_prod as $odd_prods ) {

$message .= get_the_title( $odd_prods['id'] ) .' requires a minimum quantity of '

. $odd_prods['min_req'] 

.'. You currently have: '. $odd_prods['in_cart'] .'.<br />';

}

wc_add_notice( $message, 'error' );

}

}

}

?>

Step3:

Done!!

Woocommerce - Restrict user to add products into cart with particular combination

In Woocommerce if we need to Restrict user to add products  into cart  with  particular combination, we have to follow few steps.

<?php

// Step1: 

function aelia_get_cart_contents() {
  $cart_contents = array();
  $cart = WC()->session->get( 'cart', null );
   if ( is_null( $cart ) && ( $saved_cart = get_user_meta( get_current_user_id(), '_woocommerce_persistent_cart', true ) ) ) {
    $cart = $saved_cart['cart'];
  } elseif ( is_null( $cart ) ) {
    $cart = array();
  }

  if ( is_array( $cart ) ) {
    foreach ( $cart as $key => $values ) {
      $_product = wc_get_product( $values['variation_id'] ? $values['variation_id'] : $values['product_id'] );

      if ( ! empty( $_product ) && $_product->exists() && $values['quantity'] > 0 ) {
        if ( $_product->is_purchasable() ) {
         $session_data = array_merge( $values, array( 'data' => $_product ) );
          $cart_contents[ $key ] = apply_filters( 'woocommerce_get_cart_item_from_session', $session_data, $values, $key );
        }
      }
    }
  }
  return $cart_contents;
}

// Step2:

add_action('wp_loaded', function() {
    if(!is_object(WC()->session)) {
    return;
  }

  global $allowed_cart_items;
  // I am adding products with ID 5395,5138,5046,5137,5134,5133,5131 as a combination.
  global $restricted_cart_items;
  $restricted_cart_items = array(5395,5138,5046,5137,5134,5133,5131);

  foreach(aelia_get_cart_contents() as $item) {
    if(in_array($item['data']->id, $restricted_cart_items)) {
      $allowed_cart_items[] = $item['data']->id;
    }
  }

  // Step3:

  add_filter('woocommerce_is_purchasable', function($is_purchasable, $product) {
    global $restricted_cart_items;
    global $allowed_cart_items;

    if(!empty($allowed_cart_items)) {
           $is_purchasable = in_array($product->id, $allowed_cart_items) || in_array($product->id, $restricted_cart_items);
    }
    return $is_purchasable;
  }, 10, 2);
}, 10);

// Step4

add_filter('woocommerce_get_price_html', function($price_html, $product) {
  if(!$product->is_purchasable() && is_product()) {
    $price_html .= '<p>' . __('<h3 style="font-weight:bold;">This product cannot be added to cart  with the combination of  <span style="color:#d06569">Product / Category Name</span>. Remove other items from cart and try purchasing it.</h3>', 'woocommerce') . '</p>';
  }
  return $price_html;
}, 10, 2);

// Step5

// Done!!
?>