我正在尝试创建一个插件，以使用WP List Table向所有用户显示其电子邮件和角色，但是未显示该信息，它计算了数据库中有多少用户，但未显示任何信息，请告知：
if ( ! class_exists( 'WP_List_Table' ) ) {
require_once( ABSPATH . 'wp-admin/includes/class-wp-list-table.php' );
}
class Users_List extends WP_List_Table {
/** Class constructor */
public function __construct() {
parent::__construct( [
'singular' => __( 'User', 'sp' ), //singular name of the listed records
'plural' => __( 'Users', 'sp' ), //plural name of the listed records
'ajax' => false //does this table support ajax?
] );
}
/**
* Retrieve users data from the database
*
* @param int $per_page
* @param int $page_number
*
* @return mixed
*/
public static function get_users( $per_page = 5, $page_number = 1 ) {
global $wpdb;
$sql = "SELECT * FROM {$wpdb->prefix}users";
if ( ! empty( $_REQUEST['orderby'] ) ) {
$sql .= ' ORDER BY ' . esc_sql( $_REQUEST['orderby'] );
$sql .= ! empty( $_REQUEST['order'] ) ? ' ' . esc_sql( $_REQUEST['order'] ) : ' ASC';
}
$sql .= " LIMIT $per_page";
$sql .= ' OFFSET ' . ( $page_number - 1 ) * $per_page;
$result = $wpdb->get_results( $sql, 'ARRAY_A' );
return $result;
}
/**
* Delete a user record.
*
* @param int $id user ID
*/
public static function delete_users( $id ) {
global $wpdb;
$wpdb->delete(
"{$wpdb->prefix}users",
[ 'ID' => $id ],
[ '%d' ]
);
}
/**
* Returns the count of records in the database.
*
* @return null|string
*/
public static function record_count() {
global $wpdb;
$sql = "SELECT COUNT(*) FROM {$wpdb->prefix}users";
return $wpdb->get_var( $sql );
}
/** Text displayed when no user data is available */
public function no_items() {
_e( 'No users avaliable.', 'sp' );
}
public function column_default( $item, $column_name ) {
switch ( $column_name ) {
case 'email':
case 'role':
return $item[ $column_name ];
default:
return print_r( $item, true ); //Show the whole array for troubleshooting purposes
}
}
/**
* Render the bulk edit checkbox
*
* @param array $item
*
* @return string
*/
function column_cb( $item ) {
return sprintf(
'<input type="checkbox" name="bulk-delete[]" value="%s" />', $item['ID']
);
}
/**
* Method for name column
*
* @param array $item an array of DB data
*
* @return string
*/
function column_name( $item ) {
$delete_nonce = wp_create_nonce( 'sp_delete_users' );
$title = '<strong>' . $item['name'] . '</strong>';
$actions = [
'delete' => sprintf( '<a href="?page=%s&action=%s&users=%s&_wpnonce=%s">Delete</a>', esc_attr( $_REQUEST['page'] ), 'delete', absint( $item['ID'] ), $delete_nonce )
];
return $title . $this->row_actions( $actions );
}
/**
* Associative array of columns
*
* @return array
*/
function get_columns() {
$columns = [
'cb' => '<input type="checkbox" />',
'name' => __( 'Name', 'sp' ),
'email' => __( 'Email', 'sp' ),
'role' => __( 'Role', 'sp' )
];
return $columns;
}
/**
* Columns to make sortable.
*
* @return array
*/
public function get_sortable_columns() {
$sortable_columns = array(
'name' => array( 'name', true ),
'email' => array( 'email', false )
);
return $sortable_columns;
}
/**
* Returns an associative array containing the bulk action
*
* @return array
*/
public function get_bulk_actions() {
$actions = [
'bulk-delete' => 'Delete'
];
return $actions;
}
/**
* Handles data query and filter, sorting, and pagination.
*/
public function prepare_items() {
$this->_column_headers = $this->get_column_info();
/** Process bulk action */
$this->process_bulk_action();
$per_page = $this->get_items_per_page( 'users_per_page', 5 );
$current_page = $this->get_pagenum();
$total_items = self::record_count();
$this->set_pagination_args( [
'total_items' => $total_items, //WE have to calculate the total number of items
'per_page' => $per_page //WE have to determine how many items to show on a page
] );
$this->items = self::get_users( $per_page, $current_page );
}
public function process_bulk_action() {
//Detect when a bulk action is being triggered...
if ( 'delete' === $this->current_action() ) {
// In our file that handles the request, verify the nonce.
$nonce = esc_attr( $_REQUEST['_wpnonce'] );
if ( ! wp_verify_nonce( $nonce, 'sp_delete_users' ) ) {
die( 'Go get a life script kiddies' );
}
else {
self::delete_users( absint( $_GET['user'] ) );
// esc_url_raw() is used to prevent converting ampersand in url to "#038;"
// add_query_arg() return the current url
wp_redirect( esc_url_raw(add_query_arg()) );
exit;
}
}
// If the delete bulk action is triggered
if ( ( isset( $_POST['action'] ) && $_POST['action'] == 'bulk-delete' )
|| ( isset( $_POST['action2'] ) && $_POST['action2'] == 'bulk-delete' )
) {
$delete_ids = esc_sql( $_POST['bulk-delete'] );
// loop over the array of record IDs and delete them
foreach ( $delete_ids as $id ) {
self::delete_users( $id );
}
// esc_url_raw() is used to prevent converting ampersand in url to "#038;"
// add_query_arg() return the current url
wp_redirect( esc_url_raw(add_query_arg()) );
exit;
}
}
}
class SP_Plugin {
// class instance
static $instance;
// user WP_List_Table object
public $users_obj;
// class constructor
public function __construct() {
add_filter( 'set-screen-option', [ __CLASS__, 'set_screen' ], 10, 3 );
add_action( 'admin_menu', [ $this, 'plugin_menu' ] );
}
public static function set_screen( $status, $option, $value ) {
return $value;
}
public function plugin_menu() {
$hook = add_menu_page(
'Elvio User Plugin',
'SP WP_List_Table',
'manage_options',
'wp_list_table_class',
[ $this, 'plugin_settings_page' ]
);
add_action( "load-$hook", [ $this, 'screen_option' ] );
}
/**
* Plugin settings page
*/
public function plugin_settings_page() {
?>
<div class="wrap">
<h2>Elvio User Plugin</h2>
<div id="poststuff">
<div id="post-body" class="metabox-holder columns-2">
<div id="post-body-content">
<div class="meta-box-sortables ui-sortable">
<form method="post">
<?php
$this->users_obj->prepare_items();
$this->users_obj->display(); ?>
</form>
</div>
</div>
</div>
<br class="clear">
</div>
</div>
<?php
}
/**
* Screen options
*/
public function screen_option() {
$option = 'per_page';
$args = [
'label' => 'users',
'default' => 5,
'option' => 'users_per_page'
];
add_screen_option( $option, $args );
$this->users_obj = new Users_List();
}
/** Singleton instance */
public static function get_instance() {
if ( ! isset( self::$instance ) ) {
self::$instance = new self();
}
return self::$instance;
}
}
add_action( 'plugins_loaded', function () {
SP_Plugin::get_instance();
} );
我没有PHP经验，但是我检查了所有内容，问题仍然存在