我们有一个销售电脑零件的网站,这个网站上有一个名为“组装你的电脑”的部分,允许用户选择零件(主板 – cpu – ram等)并付出代价并获得他们的组装产品,一切正常很好,但它需要一个选项来添加“装配费”到购物车.
仅当用户通过“组装您的PC”向导过程时才应添加此费用.
我正在使用此代码,但它将其添加到所有购物车,我的意思是它不是有条件的.

public function calculate_fees( $fees ){
    global $woocommerce;

    $cart_subtotal   = $woocommerce->cart->suBTotal;
    $addITional_fee = 0; // Additional fee
    $additional_fee_text = __('AsSEMbling fee : ','dornaweb');

    if( $_POST['assembly_fee'] === 'flat_assembly_rate' ){
        $additional_fee = intval( dw_option('flat_assembly_rate') ) ?: 0; // flat assembly fee
        $additional_fee_text .= __(' ( assembly,no warranty )','dornaweb');
    } elseif( $_POST['assembly_fee'] === 'PErcentage_assembly_fee' ) {
        $additional_fee = dw_option('percentage_assembly_fee') ? ( ( intval( dw_option('percentage_assembly_fee') ) / 100 ) * $cart_subtotal ) : 0; // percentage assembly fee
        $additional_fee_text .= __(' ( assembly + one year warranty )','dornaweb');
    }

    $woocommerce->cart->add_fee( $additional_fee_text,intval( $additional_fee ),1 );
}

并在构造函数上：

add_action( 'woocommerce_cart_calculate_fees',array( $this,'calculate_fees' ) );

让我解释一下这个向导(组装你的PC)的更多信息：
我们在本节中有3个步骤,

>步骤1：用户从现有的主板,Ram,cpu等中选择
产品.
>第2步：查看列表并可以更改某些产品的数量(
像拉姆)
>步骤3：用户可以通过一些选项查看最终列表
选择页面底部的装配费(1.无装配,
只需购买清单2.组装一年保修3.组装
没有保修)当他们点击“提交”时,所有选择的产品
添加到购物车,这是我们需要添加该费用的地方,所以这笔费用
只有在客户使用此进度时才应添加.

我也尝试添加费用,而我将产品添加到购物车,但它没有这种方式,当我去购物车页面,这样没有额外的费用

/* User chooses list of PRoducts ( mainboard,ram,... ) and can  choose quantity of each product 
and also can choose whether he/she wants to get an assembled computer
or just wants to buy the products individually,then when he/she hits submit products get added to cart all together
in this step assembling fee should be added and calculated in cart total */
if( !empty( $_POST['action'] ) && $_POST['action'] == 'add' ){
      /**
       * Add each product to cart based on user choice
       */
      foreach( $_POST['products'] as $product_id => $data ) {
            WC()->cart->add_to_cart( $product_id,$data['qty'] );
      }

      /**
       * Add additional fees
       */
      WC()->cart->add_fee( 'Assembling fee',10 ); // 10 is an example,the fee differs depending on user choice ( no assemble:0,asseMLby+warranty:5% of the cart subtotal,assembly+no warranty: a flat fee eg. 20$)
      WC()->cart->calculate_fees();

      /**
       * redirect to cart
       */
      wp_safe_redirect( WC()->cart->get_cart_url() );
}

if( !empty( $_POST['action'] ) && $_POST['action'] == 'add' ){
   /**
    * Add each product to cart based on user choice
    */
   foreach( $_POST['products'] as $product_id => $data ) {
        WC()->cart->add_to_cart( $product_id,$data['qty'] );
   }

   /**
    * We set sessions after products added to cart
   */
   WC()->session->set( 'MY_SESSION','My_value' );

   /**
    * Redirect to cart
    */
   wp_safe_redirect( WC()->cart->get_cart_url() );
}

function dw_calculate_fees( $cart_object ){
    global $woocommerce;
    if ( is_admin() && ! defined( 'DOING_AJAX' ) ) return;
    if( ! WC()->session->;mY_SESSION ) return;

    $cart_subtotal   = $woocommerce->cart->subtotal;
    $additional_fee = null;

    if( WC()->session->MY_SESSION === 'example_a' ){
        $additional_fee = 1;
    } elseif( WC()->session->MY_SESSION === 'example_b' ) {
        $additional_fee = 2;
    } else{
        $additional_fee = 0;
    }

    if( ! is_null( $additional_fee ) ) {
        $woocommerce->cart->add_fee( 'Additional fee ',1 );
    }
}
add_action( 'woocommerce_cart_calculate_fees','dw_calculate_fees' );

add_action( 'woocommerce_cart_emptied','dw_unset_fee_session' );
function dw_unset_fee_session(){
    unset( WC()->session->MY_SESSION );
}