PHP OOP unable to edit class properties - php

Question

New to PHP and especially OOP.
I have a class User.php which I am using in login.php.
$vars = $user->login($email, $pass)
At the moment I am calling the login method as the above, eventually I am going to call an if statment to validate, etc.
At the moment however, I am trying to connect to the DB, pull some information out and add that information to the properties in my class. I can pull the information out (verified by var_dumps of the objects in method login() (vardump of $results), yet for some reason with my current code I cannot update my class properties.
Here is my code
User.php
<?php
class User {
public $id, $password, $first_name, $last_name;
private $user_level;
protected static $db_fields = array('id', 'first_name', 'last_name', 'pass');
protected static $table_name="users";
public function login($email, $pass) {
global $database;
$sql = "SELECT user_id, first_name, last_name, user_level FROM users WHERE (email='$email' AND pass=SHA1('$pass')) AND active IS NULL LIMIT 1";
$results = self::find_by_sql($sql);
if (!empty($results)) {
$this->setuservars($results);
return array_shift($results);
} else {
return false;
}
// return !empty($results) ? array_shift($results) : false;
}
private function setuservars($uservariables) {
$this->id = $uservariables->id;
$this->first_name = $uservariables->first_name;
$this->last_name = $uservariables->last_name;
$this->user_level = $uservariables->user_level;
}
public static function find_by_sql($sql="") {
global $database;
$results_array = $database->query($sql);
$object_array = array();
while ($row = $results_array->fetch_assoc()) {
$object_array[] = self::instantiate($row);
}
return $object_array;
}
public function mysqli_array_escape($arg1){
global $database;
foreach ($arg1 as $key => $value) {
$arg1[$key] = $database->real_escape_string($value);
}
return $arg1;
}
private static function instantiate($record) {
// Could check that $record exists and is an array
$object = new self;
foreach($record as $attribute=>$value){
if($object->has_attribute($attribute)) {
$object->$attribute = $value;
}
}
return $object;
}
private function has_attribute($attribute) {
return array_key_exists($attribute, $this->attributes());
}
protected function attributes() {
// return an array of attribute names and their values
$attributes = array();
foreach(self::$db_fields as $field) {
if(property_exists($this, $field)) {
$attributes[$field] = $this->$field;
}
}
return $attributes;
}
}
$user = new User();
?>
and here is my login.php (I have edited the if statement with to verify the user logged in successfully, i have replaced with "if (1 == 1) {" statement just to help with debugging code.
if (isset($_POST['submitted'])) {
$postdata = $user->mysqli_array_escape($_POST);
//var_dump($user->results);
if (((!isset($_POST['email'])) || ($_POST['email']) == '') || (!isset($_POST['pass']) || ($_POST['pass']) == '') ) {
//error handling eventually
} else {
$email = $_POST['email'];
$pass = $_POST['pass'];
$vars = $user->login($email, $pass);
echo $vars->first_name;
if (1 == 1) {
echo "you have successfully logged in";
var_dump($user->id);
} else {
echo "not logged in";
}
}
}
Oh and the current error I am receiving is "An error occurred in script 'F:\internet\www\htdocs\blissoop\classes\User.php' on line 26: Trying to get property of non-object
Date/Time: 4-13-2012 05:01:09"

Answer 1

I have resolved this issue with help from this question
here was the code that helped : Get value from Multidimentional Array containing an Object.
I have +1'd the answer which helped.
foreach ($array as $item) {
$userId = $item->user_id;
//do something with the userId for this item
}
I had to loop through the array to be able to get the object's properties.