gdk/framework/metabox.php

<?php

if (!class_exists('myCustomFields')) {
    class myCustomFields
    {
        /**
         * @var string 自定义栏目前缀，一个完整的自定义栏目是需要前缀+name的，比如我的前缀是git_,name下面有baidu_submit，那么完整的自定义栏目就是git_baidu_submit
         */
        public $prefix = 'gdk_';
        /**
         * @var array 这是自定义面板的使用范围，这里一般就是在文章以及页面
         */
        public $postTypes = ['post'];
        /**
         * @var array 开始组件自定义面板数组
         */
        public $customFields = [
            [
                'name' => 'thumb',
                'title' => '自定义缩略图',
                'description' => '这里可以输入您的自定义缩略图链接',
                'type' => 'text',
                'scope' => ['post'],
                'capability' => 'edit_posts',
            ],
            [
                'name' => 'download_name',
                'title' => '单页下载文件名字',
                'description' => '这里可以输入您的下载文件的名字',
                'type' => 'text',
                'scope' => ['post'],
                'capability' => 'edit_posts',
            ],
            [
                'name' => 'download_size',
                'title' => '单页下载文件大小',
                'description' => '这里可以输入您的下载文件的大小，可以加上单位，比如：233KB或者233MB',
                'type' => 'text',
                'scope' => ['post'],
                'capability' => 'edit_posts',
            ],
            [
                'name' => 'download_link',
                'title' => '单页下载下载链接',
                'description' => '按照链接,名字,备注的格式,注意中间是用英文逗号,换行可添加多个,举个栗子：<code>https://www.baidu.com,百度官网,中国最大的搜索引擎网站</code>',
                'type' => 'textarea',
                'scope' => ['post'],
                'capability' => 'edit_posts',
            ],
        ];

        /**
         * PHP 5 Constructor.
         */
        public function __construct()
        {
            add_action('admin_menu', [$this, 'createCustomFields']);
            add_action('save_post', [$this, 'saveCustomFields'], 1, 2);
        }

        /**
         * 创建一组你自己的自定义栏目.
         */
        public function createCustomFields()
        {
            if (function_exists('add_meta_box')) {
                foreach ($this->postTypes as $postType) {
                    add_meta_box('my-custom-fields', '文章选项', [$this, 'displayCustomFields'], $postType, 'normal', 'high');
                }
            }
        }

        /**
         * 在文章发布页显示出来面板
         */
        public function displayCustomFields()
        {
            global $post; ?>
<div class="form-wrap">
    <?php wp_nonce_field('my-custom-fields', 'my-custom-fields_wpnonce', false, true);
            foreach ($this->customFields as $customField) {
                // Check scope
                $scope = $customField['scope'];
                $output = false;
                foreach ($scope as $scopeItem) {
                    switch ($scopeItem) {
                        default:
                                if ($post->post_type == $scopeItem) {
                                    $output = true;
                                }

                                break;
                    }
                    if ($output) {
                        break;
                    }
                }
                // 检查权限
                if (!current_user_can($customField['capability'], $post->ID)) {
                    $output = false;
                }

                // 通过则输出
                if ($output) {
                    ?>
    <div
        class="form-field form-required form-field-<?php echo $customField['name']; ?>">
        <?php switch ($customField['type']) {
                        case 'checkbox':
                                // Checkbox 组件
                                echo '<label for="'.$this->prefix.$customField['name'].'" style="display:inline;"><b>'.$customField['title'].'</b></label>  ';
                                echo '<input type="checkbox" name="'.$this->prefix.$customField['name'].'" id="'.$this->prefix.$customField['name'].'" value="1"';
                                if ('1' == get_post_meta($post->ID, $this->prefix.$customField['name'], true)) {
                                    echo ' checked="checked"';
                                }
                                echo '" style="width: auto;" />';

                                break;

                        case 'textarea':
                        case 'wysiwyg':
                                // Text area
                                echo '<label for="'.$this->prefix.$customField['name'].'"><b>'.$customField['title'].'</b></label>';
                                echo '<textarea name="'.$this->prefix.$customField['name'].'" id="'.$this->prefix.$customField['name'].'" columns="30" rows="5">'.htmlspecialchars(get_post_meta($post->ID, $this->prefix.$customField['name'], true)).'</textarea>';
                                // WYSIWYG
                                if ('wysiwyg' == $customField['type']) { ?>
        <script type="text/javascript">
            jQuery(document).ready(function() {
                jQuery(
                        "<?php echo $this->prefix.$customField['name']; ?>"
                        )
                    .addClass("mceEditor");
                if (typeof(tinyMCE) == "object" && typeof(tinyMCE.execCommand) == "function") {
                    tinyMCE.execCommand("mceAddControl", false,
                        "<?php echo $this->prefix.$customField['name']; ?>"
                    );
                }
            });
        </script>
        <?php }

                                break;

                        default:
                                // Plain text field
                                echo '<label for="'.$this->prefix.$customField['name'].'"><b>'.$customField['title'].'</b></label>';
                                echo '<input type="text" name="'.$this->prefix.$customField['name'].'" id="'.$this->prefix.$customField['name'].'" value="'.htmlspecialchars(get_post_meta($post->ID, $this->prefix.$customField['name'], true)).'" />';

                                break;
                    } ?>
        <?php if ($customField['description']) {
                        echo '<p>'.$customField['description'].'</p>';
                    } ?>
    </div>
    <?php
                }
            } ?>
</div>
<?php
        }

        /**
         * 保存自定义栏目数据.
         *
         * @param mixed $post_id
         * @param mixed $post
         */
        public function saveCustomFields($post_id, $post)
        {
            if (!isset($_POST['my-custom-fields_wpnonce']) || !wp_verify_nonce($_POST['my-custom-fields_wpnonce'], 'my-custom-fields')) {
                return;
            }

            if (!current_user_can('edit_post', $post_id)) {
                return;
            }

            if (!array_key_exists($post->post_type, $this->postTypes)) {
                return;
            }

            foreach ($this->customFields as $customField) {
                if (current_user_can($customField['capability'], $post_id)) {
                    if (isset($_POST[$this->prefix.$customField['name']]) && trim($_POST[$this->prefix.$customField['name']])) {
                        $value = $_POST[$this->prefix.$customField['name']];
                        // Auto-paragraphs for any WYSIWYG
                        if ('wysiwyg' == $customField['type']) {
                            $value = wpautop($value);
                        }

                        update_post_meta($post_id, $this->prefix.$customField['name'], $value);
                    } else {
                        delete_post_meta($post_id, $this->prefix.$customField['name']);
                    }
                }
            }
        }
    } // End Class
} // End if class exists statement

// Instantiate the class
if (class_exists('myCustomFields')) {
    $myCustomFields_var = new myCustomFields();
}