我需要在OOP PHP项目中动态显示登录用户的用户名。当我从数据库中键入正确的ID时,我可以显示它,但是当我尝试在函数find_by_id中定义属性$ user_id时,它显示错误。我需要有关如何定义$ user_id变量的帮助。这是我的代码:
index.php
<?php $user = User::find_by_id($user_id); ?>
<h1>Hello, <?php echo $user->username; ?></h1>
user.php
<?php
class User
{
protected static $db_table = "users";
public $id;
public $username;
public $password;
public $first_name;
public $last_name;
private function has_the_attribute($the_attribute)
{
$object_properties = get_object_vars($this);
return array_key_exists($the_attribute, $object_properties);
}
public static function instantation($the_record)
{
$the_object = new self;
foreach ($the_record as $the_attribute => $value) {
if ($the_object->has_the_attribute($the_attribute)) {
$the_object->$the_attribute = $value;
}
}
return $the_object;
}
public static function find_this_query($sql)
{
global $database;
$result_set = $database->query($sql);
$the_object_array = [];
while ($row = mysqli_fetch_array($result_set)) {
$the_object_array[] = self::instantation($row);
}
return $the_object_array;
}
public static function find_all()
{
return self::find_this_query("SELECT * FROM " . static::$db_table . " ");
}
public static function find_by_id($user_id)
{
global $database;
$the_result_array = self::find_this_query("SELECT * FROM " . self::$db_table . " WHERE id = $user_id");
return !empty($the_result_array) ? array_shift($the_result_array) : false;
}
public static function verify_user($username, $password)
{
global $database;
$username = $database->escape_string($username);
$password = $database->escape_string($password);
$sql = "SELECT * FROM " . self::$db_table . " WHERE ";
$sql .= "username = '{$username}' ";
$sql .= "AND password = '{$password}'";
$the_result_array = self::find_this_query($sql);
return !empty($the_result_array) ? array_shift($the_result_array) : false;
}
}
$user = new User();
session.php
<?php
class Session
{
private $signed_in = false;
public $user_id;
public $message;
public function __construct()
{
session_start();
$this->check_the_login();
$this->check_message();
}
public function login($user)
{
if ($user) {
$this->user_id = $_SESSION['user_id'] = $user->id;
$this->signed_in = true;
}
}
public function logout()
{
unset($_SESSION['user_id']);
unset($this->user_id);
$this->signed_in = false;
}
private function check_the_login()
{
if (isset($_SESSION['user_id'])) {
$this->user_id = $_SESSION['user_id'];
$this->signed_in = true;
} else {
unset($this->user_id);
$this->signed_in = false;
}
}
public function is_signed_in()
{
return $this->signed_in;
}
public function message($msg="")
{
if (!empty($msg)) {
$_SESSION['message'] = $msg;
} else {
return $this->message;
}
}
public function check_message()
{
if (isset($_SESSION['message'])) {
$this->message = $_SESSION['message'];
unset($_SESSION['message']);
} else {
$this->message = "";
}
}
}
$session = new Session();
答案 0 :(得分:0)
为了将其标记为接受,您实际上需要传递的用户ID而不是未初始化的变量,如果您的实例将其存储在会话中,那么我想它是: / p>
<?php $user = User::find_by_id($_SESSION['user_id']); ?>
注意:要使模板更简洁,可以对echo
使用简写语法:
<h1>Hello, <?= $user->username; ?></h1>
要注意的另一件事是,您已经构建了一个Session类,但是由于某种原因,您仍然出于某种原因通过$_SESSION
访问数据,因此需要进行一些设置/获取。最后,会话是您将要使用的很多东西,因此值得将该类静态化。
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