Custom cart item currency symbol based on product

Question

I want to display a custom currency symbol based on product category. I took the following snippet suggested on this question Change currency symbol based on product category in Woocommerce.

However I actually need the custom currency to be displayed also in all Woocommerce pages (including cart and checkout page).

This is my code:

add_filter('woocommerce_currency_symbol', 'change_existing_currency_symbol', 10, 2);

function change_existing_currency_symbol( $currency_symbol, $currency ) {

    global $post, $product, $woocommerce;

    if ( has_term( 'cupones', 'product_cat' ) ) :

        switch( $currency ) {
             case 'EUR': $currency_symbol = 'ptos'; break;
        }
        return $currency_symbol;

    elseif ( has_term( 'cupones', 'product_cat' ) && is_cart() ): 

        switch( $currency ) {
             case 'EUR': $currency_symbol = 'ptos'; break;
        }
        return $currency_symbol;

    elseif ( has_term( 'cupones', 'product_cat' ) && is_checkout() ): 

        switch( $currency ) {
             case 'EUR': $currency_symbol = 'ptos'; break;
        }
        return $currency_symbol;  
    endif;      
}

Answer 1

Updated: For cart and checkout pages, there is 2 ways: By item or globally.

1) BY ITEM (The most complicated):

// HERE below your settings
function custom_currency_symbol_settings(){
    return array(
        'curr_symbol' => 'ptos', // <=== HERE define your currency symbol replacement
        'currency'    => 'EUR', // <=== HERE define the targeted currency code
        'category'    => array('cupones'), // <=== HERE define your product category(ies)
        'taxonomy'    => 'product_cat',
    );
}

// On product pages - Custom currency symbol
add_filter( 'woocommerce_currency_symbol', 'change_existing_currency_symbol', 10, 2 );
function change_existing_currency_symbol( $currency_symbol, $currency ) {
    global $post, $product;

    // Loading your settings
    $data = custom_currency_symbol_settings();

    // Others Woocommerce product pages
    if ( has_term( $data['category'], $data['taxonomy'] ) && $currency == $data['currency'] ) {
        return $data['curr_symbol'];
    }

    return $currency_symbol;
}

// On cart item product price (Cart page) - Custom currency symbol
add_filter( 'woocommerce_cart_product_price', 'change_cart_item_price_currency_symbol', 10, 2 );
function change_cart_item_price_currency_symbol( $product_price_html, $product ) {

    // Loading your settings
    $data = custom_currency_symbol_settings();

    // Get the correct product ID
    $product_id = $product->is_type('variation') ? $product->get_parent_id() : $product->get_id();

    // Only for the defined product category and the defined currency
    if ( ! has_term( $data['category'], $data['taxonomy'], $product_id  ) || get_woocommerce_currency() != $data['currency'] ) {
        return $product_price_html; // Exit
    }

    if ( WC()->cart->display_prices_including_tax() ) {
        $price = wc_get_price_including_tax( $product );
    } else {
        $price = wc_get_price_excluding_tax( $product );
    }

    return wc_price_custom( $price, $data['curr_symbol'] );
}

//  On cart item line subtotal (Cart and Checkout pages) - Custom currency symbol
add_filter( 'woocommerce_cart_product_subtotal', 'change_cart_item_subtotal_currency_symbol', 10, 8 );
function change_cart_item_subtotal_currency_symbol( $product_subtotal, $product, $quantity, $cart ) {

    // Loading your settings
    $data = custom_currency_symbol_settings();

    // Get the correct product ID
    $product_id = $product->is_type('variation') ? $product->get_parent_id() : $product->get_id();

    // Only for the defined product category and the defined currency
    if ( ! has_term( $data['category'], $data['taxonomy'], $product_id  ) || get_woocommerce_currency() != $data['currency'] ) {
        return $product_price_html; // Exit
    }

    if ( $product->is_taxable() ) {

        if ( $cart->display_prices_including_tax() ) {
            $row_price        = wc_get_price_including_tax( $product, array( 'qty' => $quantity ) );
            $product_subtotal = wc_price_custom( $row_price, $data['curr_symbol'] );

            if ( ! wc_prices_include_tax() && $cart->get_subtotal_tax() > 0 ) {
                $product_subtotal .= ' <small class="tax_label">' . WC()->countries->inc_tax_or_vat() . '</small>';
            }
        } else {
            $row_price        = wc_get_price_excluding_tax( $product, array( 'qty' => $quantity ) );
            $product_subtotal = wc_price_custom( $row_price, $data['curr_symbol'] );

            if ( wc_prices_include_tax() && $cart->get_subtotal_tax() > 0 ) {
                $product_subtotal .= ' <small class="tax_label">' . WC()->countries->ex_tax_or_vat() . '</small>';
            }
        }
    } else {
        $row_price        = $product->get_price() * $quantity;
        $product_subtotal = wc_price_custom( $row_price, $data['curr_symbol'] );
    }
    return $product_subtotal;
}

// Custom formatting price function replacement
function wc_price_custom( $price, $curr_symbol, $args = array() ){
    extract( apply_filters( 'wc_price_args', wp_parse_args( $args, array(
        'ex_tax_label'       => false,
        'currency'           => '',
        'decimal_separator'  => wc_get_price_decimal_separator(),
        'thousand_separator' => wc_get_price_thousand_separator(),
        'decimals'           => wc_get_price_decimals(),
        'price_format'       => get_woocommerce_price_format(),
    ) ) ) );

    $unformatted_price = $price;
    $negative          = $price < 0;
    $price             = apply_filters( 'raw_woocommerce_price', floatval( $negative ? $price * -1 : $price ) );
    $price             = apply_filters( 'formatted_woocommerce_price', number_format( $price, $decimals, $decimal_separator, $thousand_separator ), $price, $decimals, $decimal_separator, $thousand_separator );

    if ( apply_filters( 'woocommerce_price_trim_zeros', false ) && $decimals > 0 ) {
        $price = wc_trim_zeros( $price );
    }

    $formatted_price = ( $negative ? '-' : '' ) .
        sprintf( $price_format, '<span class="woocommerce-Price-currencySymbol">' . $curr_symbol . '</span>', $price );
    $return          = '<span class="woocommerce-Price-amount amount">' . $formatted_price . '</span>';

    if ( $ex_tax_label && wc_tax_enabled() ) {
        $return .= ' <small class="woocommerce-Price-taxLabel tax_label">' . WC()->countries->ex_tax_or_vat() . '</small>';
    }
    return apply_filters( 'wc_price', $return, $price, $args, $unformatted_price );
}

2) GLOBALLY (Much more easier):

The following code based on your code settings will change the currency symbol globally on cart and on checkout pages too, When 'cupones' product category is found in any cart item:

add_filter( 'woocommerce_currency_symbol', 'change_existing_currency_symbol', 10, 2 );
function change_existing_currency_symbol( $currency_symbol, $currency ) {
    global $post, $product;

    $custom_sym = 'ptos'; // <=== HERE define your currency symbol replacement
    $custom_cur = 'EUR'; // <=== HERE define the targeted currency code
    $category   = array('cupones'); // <=== HERE define your product category(ies)
    $taxonomy   = 'product_cat';

    // Cart and checkout
    if( ( is_cart() || is_checkout() ) && $currency == $custom_cur ){
        foreach( WC()->cart->get_cart() as $cart_item ){
            if ( has_term( $category, $taxonomy, $cart_item['product_id'] ) ){
                return $custom_sym; // Found! ==> we return the custom currency symbol
            }
        }
    }

    // Others Woocommerce product pages
    if ( has_term( $category, $taxonomy ) && $currency == $custom_cur ) {
        return $custom_sym;
    }

    return $currency_symbol;
}

Code goes in function.php file of your active child theme (or active theme). Tested and works.