基于 WooCommerce 中所选品牌的动态选择字段选项

Question

在 woocommerce 中，我有 2 个选择字段：

• 第一个是“汽车品牌”，
• 第二个是Car Brands 中的“汽车模型”。

我想做的是为选定的“汽车品牌”动态获取“汽车模型”

“汽车品牌”来自 WooCommerce 产品属性分类法。对于每个“汽车品牌”，相关的“汽车型号”是该产品属性分类的术语。

这是“汽车品牌”的代码（第一个选择字段）：

$attributes =  wc_get_attribute_taxonomies();

if($attributes) {
    echo '<select id="car-brands"><option value="noselection">Car Brand</option>';
    foreach ( $attributes as $attribute ) {
        echo '<option value="' . $attribute->attribute_name . '">' . $attribute->attribute_label . '</option>';
    }
    echo '</select>';
}

还有一个生成的html示例代码：

<select id="car-brands">
    <option value="noselection">Car Brand</option>
    <option value="toyota">TOYOTA</option>
    <option value="lexus">LEXUS</option>
</select>

然后是“汽车型号”的代码（第二个选择字段）：

$selected_attribute_name = 'toyota';
$taxonomy = 'pa_' . $selected_attribute_name;
$term_names = get_terms( array( 'taxonomy' => $taxonomy, 'fields' => 'names' ) );

echo '<select id="car-models"><option value="noselection">Car Model</option>';
echo '<option>' . implode( '</option><option>', $term_names ) . '</option>';
echo '</select>';

还有一个生成的html示例代码：

<select id="car-models">
    <option value="noselection">Car Model</option>
    <option value="toyota">AVENSIS</option>
    <option value="lexus">CAMRY</option>
</select>

如您所见，我正在获取“丰田”品牌的特定车型，因为我已将“丰田”硬编码为“汽车品牌”：

$selected_attribute_name = 'toyota';

所以我希望将$selected_attribute_name 作为动态变量，因此当用户选择汽车品牌“LEXUS”或“TOYOTA”时，第二个选择字段会动态加载相关术语（选项） em>。

我找到了很多相关的线程，但我无法理解如何使它适用于我的案例。

如何根据选定的汽车品牌让动态“汽车模型”选择字段选项？

---

编辑

我所有的 php 都在一个动作钩子函数中，如下所示：

function _themename_woocommerce_custom_filter() {
    $attributes =  wc_get_attribute_taxonomies();

    if($attributes) {
        echo '<select id="car-brands"><option value="noselection">Car Brand</option>';
        foreach ( $attributes as $attribute ) {
            echo '<option value="' . $attribute->attribute_name . '">' . $attribute->attribute_label . '</option>';
        }
        echo '</select>';
    }

    $selected_attribute_name = '';
    $taxonomy = 'pa_' . $selected_attribute_name;
    $term_names = get_terms( array( 'taxonomy' => $taxonomy, 'fields' => 'names' ) );

    echo '<select id="car-models"><option value="noselection">Car Model</option>';
    echo '<option>' . implode( '</option><option>', $term_names ) . '</option>';
    echo '</select>';
}
add_action( 'woocommerce_before_shop_loop', '_themename_woocommerce_custom_filter', 3 );

Answer 1

下面使用Ajax从选中的“汽车品牌”中获取对应的词条（产品属性分类）动态生成“车型”选择字段选项（选中的词条产品属性分类）：

// Display 2 select fields (car brands and car models)
add_action( 'woocommerce_before_shop_loop', 'before_shop_loop_action_callback', 3 );
function before_shop_loop_action_callback() {
    if( $attributes =  wc_get_attribute_taxonomies() ) {

        ## 1st dropdown

        echo '<select id="car-brands" style="min-width:100px;"><option value="">' . __("Car Brand"). '</option>';

        // Loop through attribute taxonomies
        foreach ( $attributes as $attribute ) {
            echo '<option value="' . $attribute->attribute_name . '">' . $attribute->attribute_label . '</option>';
        }
        echo '</select>';

        ## 2nd dropdown

        echo '<select id="car-models" style="min-width:100px;"><option value=""> … </option></select>';
    }
}

// jQuery / Ajax (client side)
add_action( 'wp_footer', 'car_brand_selectors_script' );
function car_brand_selectors_script() {
    ?>
    <script type="text/javascript">
    jQuery(function( $ ) {
        if (typeof woocommerce_params === 'undefined')
            return false;

        var b = 'select#car-brands', // 1st field
            m = 'select#car-models', // 2nd field
            r = $(m).html(); // Original 2nd field select options

        function ajaxSendCarBrand( carBrand ) {
            $.ajax({
                url: woocommerce_params.ajax_url,
                type : 'POST',
                data : {
                    'action' : 'get_brand_terms',
                    'car_brand' : carBrand
                },
                success: function( response ) {
                    var options = $.parseJSON(response),
                        opt     = '';

                    if ( $.isEmptyObject(options) ) {
                        $(m).html(r);
                    } else {
                        $.each( options, function( key, value ){
                            opt += '<option value="'+key+'">'+value+'</option>';
                        });
                        $(m).html(opt);
                    }
                }
            });
        }

        // On change live event
        $( document.body ).on( 'change', b, function() {
            ajaxSendCarBrand($(this).val());
        });
    });
    </script>
    <?php
}

// WP AJAX HANDLER (Server side)
add_action('wp_ajax_get_brand_terms', 'get_car_brand_models');
add_action('wp_ajax_nopriv_get_brand_terms','get_car_brand_models');
function get_car_brand_models() {
    if( isset($_POST['car_brand']) ) {
        $brand    = wc_clean( $_POST['car_brand'] );
        $taxonomy = wc_attribute_taxonomy_name($brand);
        $options  = [];

        if( taxonomy_exists( $taxonomy ) ) {
            $terms   = get_terms( array( 'taxonomy' => $taxonomy ) );

            foreach( $terms as $term ){
                $options[$term->slug] = $term->name;
            }
        }
        echo json_encode( $options );
    }
    wp_die();
}

代码在您的活动子主题（或活动主题）的functions.php 文件中。经过测试并且可以工作。

Answer 2

这里看一个有效的 ajax 示例。

Javascript 部分：

jQuery('#car-brands').change(function() {
    let carBrandName = jQuery(this).val();
    YourFunctionNameHere(carBrandName);
});

//function to execute
function YourFunctionNameHere(carBrandName) {
    //formdata variable consists of
    //action: this is ajax action name for WordPress which we define in PHP with a callback function with same name. See in PHP code part.
    //brandName: this is your custom post attributes name
    let formdata = "action=get_car_models&brandName="+carBrandName;
    jQuery.ajax({
        type: "POST",
        url: ajaxurl, // since WordPress version 2.8 ajaxurl is always defined in the admin header and points to admin-ajax.php
        data: formdata,
        cache: false,
        success: function(response, textStatus, jqXHR) {
            jQuery("#car-models").html(response);
        },
        error: function(jqXHR, textStatus, errorThrown) {
            //do stuff here in case of error
        }
    });
}

PHP部分：

 //here wp_ajax is the required prefix for your custom actions
 //first parameter is action name with wp_ajax prefix
 //second parameter is callback function to execute with same name as your action
 //for example if your action name is wp_ajax_get_car_models then your callback will be get_car_models
add_action( 'wp_ajax_get_car_models', 'get_car_models' );

function get_car_models() {
    global $wpdb; // this is how you get access to the database
//require_once any files here in which the below code is available or just write your code here.
    $selected_attribute_name = $_POST['brandName'];
    $taxonomy = 'pa_' . $selected_attribute_name;
    $term_names = get_terms( array( 'taxonomy' => $taxonomy, 'fields' => 'names' ) );
    $html = '';
    $html .= '<select id="car-models"><option value="noselection">Car Model</option>';
    $html .= '<option>' . implode( '</option><option>', $term_names ) . '</option>';
    $html .= '</select>';
    echo $html;
    wp_die(); // this is required to terminate immediately and return a proper response

}