Gabor

add_filter('woocommerce_available_payment_gateways','bbloomer_unset_gateway_by_category');

function bbloomer_unset_gateway_by_category($available_gateways){
global $woocommerce;
$category_IDs = array(38,39);
foreach ($woocommerce->cart->cart_contents as $key => $values ) {
$terms = get_the_terms( $values['product_id'], 'product_cat' );
foreach ($terms as $term) {
if(in_array($term->term_id, $category_IDs)){
unset( $available_gateways['cod'] );
break;
}
break;
}
}
return $available_gateways;
}

//send customer directly to the checkout
add_filter('add_to_cart_redirect', 'theme_prefix_add_to_cart_redirect');
function theme_prefix_add_to_cart_redirect() {
global $woocommerce;
$checkout_url = $woocommerce->cart->get_checkout_url();
return $checkout_url;
}

//REMOVE QUANTITY FIELD
add_filter( 'woocommerce_is_sold_individually', 'wc_remove_all_quantity_fields', 10, 2 );
function wc_remove_all_quantity_fields( $return, $product ) {
return( true );
}

//CHANGE ADD TO CART BUTTON TEXT
add_filter( 'woocommerce_product_single_add_to_cart_text', 'woo_custom_single_add_to_cart_text' ); // 2.1 +

function woo_custom_single_add_to_cart_text() {

return __( 'Kosárba teszem', 'woocommerce' );

}

Version 1

// =========================================================================
// ADD TEXT TO SPECIFIC PRODUCT CATEGORY
// =========================================================================
function function_name( $attr ) {
    global $product;
    if ( has_term( 'category_name', 'product_cat', $product->get_id() ) ) {
        echo 'TESZT';
    }
    return $attr;
}
add_filter( 'woocommerce_share', 'function_name' );

Version 2

// =========================================================================
// ADD TEXT TO SPECIFIC PRODUCT CATEGORY
// =========================================================================
function add_text_to_spec_cat() {
    global $post;
    $terms = wp_get_post_terms( $post->ID, 'product_cat' );
    foreach ( $terms as $term ) $categories[] = $term->slug;
    if ( in_array( 'szivar', $categories ) ) {
        echo 'TESZT';
    }
}
add_filter( 'woocommerce_after_single_product', 'add_text_to_spec_cat' );

remove_action( 'woocommerce_single_product_summary',
'woocommerce_template_single_price', 10 );
add_action( 'woocommerce_single_product_summary',
'woocommerce_template_single_price', 30 );

//FIX COLLAPSED RELATED PRODUCTS
add_filter( 'woocommerce_after_single_product_summary', 'add_clear_both' );
function add_clear_both( $clear_both ) {
echo '<div class="clear"></div>';
return $clear_both;
}

[product_category category=”” per_page=”40″ columns=”3″ orderby=”rand”]

// New order e-mail custom text if coupon is used
add_filter( 'woocommerce_email_after_order_table', 'add_custom_email_text' );

function add_custom_email_text($order) {
if ($order->get_used_coupons()){
echo '';
}
else{
echo '';
}
}

//Redirect after registration
add_filter( 'woocommerce_registration_redirect', 'custom_redirection_after_registration', 10, 1 );
function custom_redirection_after_registration( $redirection_url ){
if ( WC()->cart->get_cart_contents_count() == 0 ) {
$redirection_url = get_permalink( wc_get_page_id( 'shop' ) );

}else{

// Change the redirection Url
$redirection_url = wc_get_checkout_url(); //Checkout
}

return $redirection_url; // Always return something
}

/*
"Home" Url: $redirection_url = get_home_url();
"Shop" Url: $redirection_url = get_permalink( wc_get_page_id( 'shop' ) );
"Cart" Url: $redirection_url = wc_get_cart_url();
"Checkout" Url: $redirection_url = wc_get_checkout_url();
"Account" $redirection_url = get_permalink( wc_get_page_id( 'myaccount' ) );
"ID": $redirection_url = get_permalink( $post_id );
(where $post_id is the id of the post or the page)
Get post or pages by path (example): $redirection_url = home_url('/product/ninja/');
*/

/**
* EXCLUDE PRODUCTS FROM SPECIFIC CATEGORY IN SHOP PAGE
*/
function custom_pre_get_posts_query( $q ) {

$tax_query = (array) $q->get( 'tax_query' );

$tax_query[] = array(
'taxonomy' => 'product_cat',
'field' => 'slug',
'terms' => array( 'havi-meglepetes-palinkacsomagok' ), // Don't display products in the clothing category on the shop page.
'operator' => 'NOT IN'
);

$q->set( 'tax_query', $tax_query );

}
add_action( 'woocommerce_product_query', 'custom_pre_get_posts_query' );