避免“调用成员函数get_cart()…”错误WooCommerce函数

Question

在以前确实工作过的代码上收到一个错误，但是现在它阻止我在wordpress中编辑一个页面(就像我试图编辑一个页面时，它说有一个严重的错误)。

下面的代码基本上改变了“添加到购物车”按钮的文本，这取决于相关产品是否在购物车中。

下面的代码和下面的错误异常：

function woocommerce_custom_add_to_cart_text($add_to_cart_text, $product ) {
    global $woocommerce;
    // Get cart
    $cart_items = $woocommerce->cart->get_cart();

    foreach ( $cart_items as $cart_item_key => $cart_item ) {
        // Get product id in cart
        $_product_id = $cart_item['product_id'];
 
        if ( $product->get_id() == $_product_id ) {
            $add_to_cart_text = 'Already in cart';
        }
    }

    return $add_to_cart_text;
  
}
add_filter( 'woocommerce_product_add_to_cart_text', 'woocommerce_custom_add_to_cart_text', 10, 2 );

错误异常：

An error of type E_ERROR was caused in line 3 of the file /home4/metisonl/public_html/staging/4326/wp-content/plugins/code-snippets/php/snippet-ops.php(446) : eval()'d code. Error message: Uncaught Error: Call to a member function get_cart() on null in /home4/metisonl/public_html/staging/4326/wp-content/plugins/code-snippets/php/snippet-ops.php(446) : eval()'d code:3
Stack trace:
#0 /home4/metisonl/public_html/staging/4326/wp-includes/class-wp-hook.php(287): woocommerce_custom_add_to_cart_text('Add to cart', Object(WC_Product_Simple))
#1 /home4/metisonl/public_html/staging/4326/wp-includes/plugin.php(206): WP_Hook->apply_filters('Add to cart', Array)
#2 /home4/metisonl/public_html/staging/4326/wp-content/plugins/woocommerce/includes/class-wc-product-simple.php(62): apply_filters('woocommerce_pro...', 'Add to cart', Object(WC_Product_Simple))
#3 /home4/metisonl/public_html/staging/4326/wp-content/plugins/woo-gutenberg-products-block/src/BlockTypes/AbstractProductGrid.php(473): WC_Product_Simple->add_to_cart_text()
#4 /home4/metisonl/public_html/staging/4326/wp-content/plugins/woo-gutenberg-products-block/src/BlockTypes/AbstractProductGrid.php(446): Automattic\WooCommerce\Blocks\BlockTypes\Abstra

Answer 1

更新的…您需要检查cart对象是否存在且购物车不为空，因此请尝试以下操作以避免此类错误：

add_filter( 'woocommerce_product_add_to_cart_text', 'filter_product_add_to_cart_text', 10, 2 );
function filter_product_add_to_cart_text( $add_to_cart_text, $product ) {
    if ( ! WC()->cart && WC()->cart->is_empty() ) 
        return $add_to_cart_text;

    // Loop through cart items
    foreach ( WC()->cart->get_cart() as $cart_item ) {
        // Get product id in cart
        $_product_id = $cart_item['product_id'];
 
        if ( $product->get_id() == $_product_id ) {
            return __('Already in cart');
        }
    }
    return $add_to_cart_text;
}

代码位于活动子主题(或活动主题)的functions.php文件中。测试和工作。