My custom meta box correctly saves my file upload. When the user wants to clear the field, they can click delete and I want to delete that meta data of the file URL only. How can I assign the meta_id correctly to the $meta_id variable in my function?
And I need to assign this meta_id, for example, to $meta_id
Here is the function creating this box as well as the save function.
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" />';
$pdf = get_post_meta(get_the_ID(), 'wp_custom_attachment', true);
if($pdf['url']){
$html .= '<p style="overflow-wrap: break-word;">Current file: ' .$pdf['url'] . '</p>';
}
$delete_nonce = wp_create_nonce( 'delete-meta_' . $meta_id );
$html.=get_submit_button( __( 'Delete' ), "delete:wp_custom_attachment:meta-{$meta_id}::_ajax_nonce=$delete_nonce deletemeta", "deletemeta[{$meta_id}]", false, array( 'tabindex' => '6' ) );
$html.=wp_nonce_field( 'change-meta', '_ajax_nonce', false, false );
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('page' == $_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: ' . $upload['error']);
} else {
update_post_meta($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');
