PHP - 在 class 期间更改 属性 的值

Question

我的 class 有两个功能，需要使用一个功能的信息来对另一个功能做出决定。我虽然可以更改 属性 的值，就像它在 Javascript 函数中一样，只需将它设置为一个新值，但这是一个很大的误解。如何在整个 class 中更改 属性 的值？

class Show_Or_Not {

    public $num;

    public function __construct() {

     add_action( 'woocommerce_cart_calculate_fees', array( $this, 'check_cart_for_condition'), 50 );
     add_filter( 'wc_add_to_cart_message', array( $this, 'use_the_cart_condition'), 100, 2 );

    }

    public function check_cart_for_condition() {

      // Ton of code checking how often a certain category occurs in the cart.

      if ( $cat_in_cart == 1 ) {
          // Trying to update value of class property in 
          // order to use it in the next function.
          $this->num = 1;
      } elseif ( $cat_in_cart == 2 ) {
          // Trying to update value of class property in 
          // order to use it in the next function.
          $this->num = 2;
      }

    }

    public function use_the_cart_condition() {

      // If condition determined in upper function is met. 
      if ( $this->num == 1 ) {
         // Do something
      } elseif ( $this->num == 2 ) {
         // Do something
      }

    }

}

$newClass = new Show_Or_Not();

Answer 1

当您调用动作或过滤器时，第二个值需要是可以在主题的 functions.php 文件中找到的方法的名称。您可以将自定义方法添加到文件中。

// In the functions.php file for the theme

function check_cart_for_condition() {
     // get the session
     global $session;

    // initialize the $num var
    $num = 0;
    // Ton of code checking how often a certain category occurs in the cart.
    if ( $cat_in_cart == 1 ) {
        // Trying to update value of class property in 
        // order to use it in the next function.
        $num = 1;
     } elseif ( $cat_in_cart == 2 ) {
        // Trying to update value of class property in 
        // order to use it in the next function.
        $num = 2;
    }

    // This only needs to be for the next request since the hooks
    // run back to back, add it to the session flash data
    $session->set_flashdata( 'num', $num );
}


public function use_the_cart_condition() {
     global $session;
     // Retrieve Flashdata
     $num = $session->flashdata( 'num' );

    // If condition determined in upper function is met. 
    if ( $this->num == 1 ) {
       // Do something
    } elseif ( $this->num == 2 ) {
       // Do something
    }
}

现在只需将其添加到您需要的代码中即可：

 add_action( 'woocommerce_cart_calculate_fees','check_cart_for_condition', 50 );
 add_filter( 'wc_add_to_cart_message','use_the_cart_condition', 100, 2 );