How to show number of items in cart and total in WordPress Header or Menu Section

Add this code to you Functions.php file 


//check if woocommerce plugin is activated
if ( ! function_exists( 'is_woocommerce_activated' ) ) {
function is_woocommerce_activated() {
if ( class_exists( 'woocommerce' ) ) {
return true;
}
else {
return false;
}
}
}


//showing cart header menu item
function andro_cart_menu_item() {
if(is_woocommerce_activated()){
?>

<li class="border"><a class="cart collapsed" data-target=".shopping-bag" href="javascript:;">
<span class="cart-icon"><?php esc_attr_e('Cart','andro');?></span>

<?php
global $woocommerce;
$my_cart_count = $woocommerce->cart->cart_contents_count;

echo '<span class="cart-number-box';
if ($my_cart_count > 0) {
echo ' active';
}
echo '">';echo sprintf( _n('%d', '%d', $woocommerce->cart->cart_contents_count, 'woothemes' ), $woocommerce->cart->cart_contents_count );
echo '</span>';
?>
</a></li>
<?php }
}

function andro_cart_shopping_bag(){
if(is_woocommerce_activated()){
?>
<div class="shopping-bag">
<?php
if ( version_compare( WOOCOMMERCE_VERSION, "2.0.0" ) >= 0 ) {
the_widget( 'WC_Widget_Cart', 'title=' );
} else {
the_widget( 'WooCommerce_Widget_Cart', 'title=' );
} ?>
</div>
<?php
}
}

add_filter( 'add_to_cart_fragments', 'woocommerce_header_add_to_cart_fragment' );

if ( ! function_exists( 'woocommerce_header_add_to_cart_fragment' ) ) {
function woocommerce_header_add_to_cart_fragment( $fragments ) {
global $woocommerce;
ob_start();
?>

<?php
echo '<span class="cart-number-box';
$my_cart_count = $woocommerce->cart->cart_contents_count;
if ($my_cart_count > 0) {
echo ' active';
}
echo '">';
?>
<?php
echo sprintf( _n('%d', '%d', $woocommerce->cart->cart_contents_count, 'woothemes' ), $woocommerce->cart->cart_contents_count );
?></span>


<?php

$fragments['span.cart-number-box'] = ob_get_clean();

return $fragments;
} // End woocommerce_header_add_to_cart_fragment()
}



After that add this code to your header.php 

To show the cart count:
<?php echo sprintf (_n( '%d item', '%d items', $woocommerce->cart->cart_contents_count ), $woocommerce->cart->cart_contents_count ); ?> - <?php echo $woocommerce->cart->get_cart_total(); ?>

or 

<?php if (class_exists('Woocommerce')) {andro_cart_menu_item();} ?>


To show the cart bag or cart Widget: 

<?php  if (class_exists('Woocommerce')) {andro_cart_shopping_bag();} ?>


Sample Header: 

<div class="top-cart">
<div id="cart" class="btn-group btn-block">
<button type="button" data-toggle="dropdown" data-loading-text="Loading..." class="btn btn-inverse btn-block btn-lg dropdown-toggle">
<span class="top-cart-contain">
<span class="title-cart"></span>
<span id="cart-total">

<?php echo sprintf (_n( '%d item', '%d items', $woocommerce->cart->cart_contents_count ), $woocommerce->cart->cart_contents_count ); ?> - <?php echo $woocommerce->cart->get_cart_total(); ?>

<?php if (class_exists('Woocommerce')) {andro_cart_menu_item();} ?>
</span>
<i class="fa fa-caret-down"></i>
</span>
</button>


<ul class="dropdown-menu pull-right">
<li class="arrow-cart"></li>
<li>
<?php  if (class_exists('Woocommerce')) {andro_cart_shopping_bag();} ?>
</li>
</ul>
</div>
</div>

Add a custom tab to woocommerce single product page

Add this below code to your functions.php file. Then chnage the line that shows

echo '<p>Here\'s your new product tab.</p>';

You can create a meta field for single product and echo that field here.

echo '<p>Your Meta box output code here</p>';




add_filter( 'woocommerce_product_tabs', 'woo_new_product_tab' );
function woo_new_product_tab( $tabs ) {

// Adds the new tab

$tabs['test_tab'] = array(
'title' => __( 'New Product Tab', 'woocommerce' ),
'priority' => 50,
'callback' => 'woo_new_product_tab_content'
);

return $tabs;

}
function woo_new_product_tab_content() {

// The new tab content

echo '<h2>New Product Tab</h2>';
echo '<p>Here\'s your new product tab.</p>';

}




#Use the following snippet to change the tab order

add_filter( 'woocommerce_product_tabs', 'woo_reorder_tabs', 98 );
function woo_reorder_tabs( $tabs ) {

$tabs['reviews']['priority'] = 5; // Reviews first
$tabs['description']['priority'] = 10; // Description second
$tabs['additional_information']['priority'] = 15; // Additional information third

return $tabs;
}

How to Override woocommerce widgets

Here, I tried to show how to override WooCommerce Price Filter widget.

At first Add this below code to your functions.php file.  copy the  class-wc-widget-price-filter.php   file from wp-content\plugins\woocommerce\includes\widgets  to your theme file and include that by
include_once  or include get_template_directory()


/*-------------------------------
 Override woocommerce product categories widgets
---------------------------------*/

add_action( 'widgets_init', 'override_woocommerce_widgets', 15 );

function override_woocommerce_widgets() {
  // Ensure our parent class exists to avoid fatal error

    if ( class_exists( 'WC_Widget_Price_Filter' ) ) {
    unregister_widget( 'WC_Widget_Price_Filter' );

    include_once( 'inc/custom-widgets/fengo-class-wc-widget-price-filter.php' ); 
//or 
//include get_template_directory() . '/inc/custom-widgets/fengo-class-wc-widget-price-filter.php';

    register_widget( 'Fengo_WC_Widget_Price_Filter' );
  }    

}