如何在wordpress中添加为自定义帖子类型元框附加的动态多个文件

Question

我正在尝试为我的WordPress网站制作一个名为books的自定义帖子类型。我当前的代码可以从元框上传一个文件。有没有办法动态上传多个文件或基于从元框自定义帖子类型的条件？

我当前的代码

<?php
function add_custom_meta_boxes() {
// Define the custom attachment for posts
add_meta_box(
'wp_custom_attachment',
'Custom Attachment',
'wp_custom_attachment',
'books', //post type name
'side'
);
} // end add_custom_meta_boxes
add_action('add_meta_boxes', 'add_custom_meta_boxes');
function wp_custom_attachment() {
wp_nonce_field(plugin_basename(__FILE__), 'wp_custom_attachment_nonce');
$html = '<p class="description">';
$html .= 'Upload your PDF here.';
$html .= '</p>';
$html .= '<input type="file" id="wp_custom_attachment" name="wp_custom_attachment" value="" size="25" />';
echo $html;
} // end wp_custom_attachment

function save_custom_meta_data($id) {
/* --- security verification --- */
if(!wp_verify_nonce($_POST['wp_custom_attachment_nonce'], plugin_basename(__FILE__))) {
return $id;
} // end if
if(defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {
return $id;
} // end if
if('books' == $_POST['post_type']) {
if(!current_user_can('edit_page', $id)) {
return $id;
} // end if
} else {
if(!current_user_can('edit_page', $id)) {
return $id;
} // end if
} // end if
/* - end security verification - */
// Make sure the file array isn't empty
if(!empty($_FILES['wp_custom_attachment']['name'])) {
// Setup the array of supported file types. In this case, it's just PDF.
$supported_types = array('application/pdf');
// Get the file type of the upload
$arr_file_type = wp_check_filetype(basename($_FILES['wp_custom_attachment']['name']));
$uploaded_type = $arr_file_type['type'];
// Check if the type is supported. If not, throw an error.
if(in_array($uploaded_type, $supported_types)) {
// Use the WordPress API to upload the file
$upload = wp_upload_bits($_FILES['wp_custom_attachment']['name'], null, file_get_contents($_FILES['wp_custom_attachment']['tmp_name']));
if(isset($upload['error']) && $upload['error'] != 0) {
wp_die('There was an error uploading your file. The error is: ' . $upload['error']);
} else {
add_post_meta($id, 'wp_custom_attachment', $upload);
update_post_meta($id, 'wp_custom_attachment', $upload);     
} // end if/else
} else {
wp_die("The file type that you've uploaded is not a PDF.");
} // end if/else
} // end if
} // end save_custom_meta_data
add_action('save_post', 'save_custom_meta_data');
function update_edit_form() {
echo ' enctype="multipart/form-data"';
} // end update_edit_form
add_action('post_edit_form_tag', 'update_edit_form');

Answer 1

上传多个文件需要您以不同的方式处理$_FILES，因为 PHP 如何组织上传数据。有关详细信息，请参阅此文档。

代码中的另一个问题是它不会为上传的文件生成元数据，这使得它们在媒体库中不可用。

为了避免这些问题，我建议使用自定义字段插件自动为您处理它们。