I am working on a basic shopping cart. However, it appears as though the $_SESSION variable is not properly being stored or accessed. For instance if you travel to here it will display the item name. But on refresh to cart.php without any $_GET variables it returns nothing. What am I doing wrong?
<?php
include "tickets/config.php";
if (isset ($_GET['action']) && isset($_GET['item'])) {
$cart = new Cart($_GET['item']);
if ($_GET['action'] == "addItem") {
$cart->addItem();
$cart->get_items_code();
$cart->populate();
}
if($_GET['action'] == "removeItem") {
$cart->removeItem();
$cart->get_items_code();
$cart->populate();
}
$cart->postAllItems();
}
else {
$cart = new Cart(null);
$cart->get_items_code();
$cart->populate();
$cart->postAllItems();
}
class Cart {
protected $all_items = array();
protected $request_item;
protected $content;
protected $item_obj;
public function __construct($request_item) {
$this->request_item = $request_item;
if ($this->request_item)
$this->item_obj = new Item($this->request_item);
$this->all_items = $this->getAllItems();
}
public function getAllItems() {
if ($_SESSION['cart'])
$request = $_SESSION['cart'];
else
$request = array();
return $request;
}
public function postAllItems() {
$_SESSION['cart'] = $this->all_items;
}
public function addItem () {
array_push($this->all_items, $this->item_obj);
}
public function removeItem() {
unset($this->all_items[$this->item_obj->get_item()]);
}
public function get_items_code() {
//for($i = 0; $this->all_items[$i]; $i++) {
foreach($this->all_items as $item) {
$name = $item->get_name();
$this->content .= <<<HTML
<div class="item">
$name
</div>
HTML;
}
}
public function populate() {
echo <<<HTML
<div id="list">
$this->content
<div>
HTML;
}
}
class Item {
protected $id;
protected $name;
protected $price;
protected $desc;
protected $colors;
protected $sizes;
protected $pic_url;
protected $all_info;
public function __construct($id) {
$this->id = $id;
$this->get_item_info();
}
public function get_item() {
return ($this);
}
public function get_name() {
return $this->name;
}
protected function get_item_info() {
$sql = "SELECT * FROM catalog WHERE id = ".$this->id;
$this->all_info = mysql_query($sql);
$this->all_info = mysql_fetch_array($this->all_info);
$this->name = $this->all_info['name'];
$this->price = $this->all_info['price'];
$this->desc = $this->all_info['description'];
$this->colors = $this->all_info['colors'];
$this->sizes = $this->all_info['sizes'];
$this->pic_url = $this->all_info['picture'];
}
}
?>
You need to initialize the session using the session_start()-function at the top of the page (before the contents of the sessions are modified or read).
Your code looks fine, but you must call session_start() on every page that modifies the session or reads from the session. Just putting it at the top of the page will work.
session_start();
I also recently had a problem with $_SESSION vars maintaining themselves after page redirects, which could be your problem.
Session variables will not survive a redirect from a http://www.example.com to a http://example.com redirect. So, you use redirects with relative or absolute paths, but do it without the sitename:
use
header('Location: /new_page.php');
as opposed to
header('Location: http://www.exmple.com/new_page.php')
Maybe doesn't apply here, but did trip me up quite a bit.
Related
I have a problem. I want some data out my database.
I have two page's a categorie.php here I want that he shows everything out the database. And I have a second page. Here are my classes. I have trying a foreach on the categorie.php but if I do that, than shows he 1 thing out the database 4 times the same and not the another data.
Below you can see my code.
I hope that you can help me.
Thank you.
This is my categorie.php
<?php
require_once '../app/functions/second.php';
require_once '../app/db/dbpassword.php';
require_once 'include/head.php';
if (isset($_GET['categorie']) && !empty($_GET['categorie'])) {
$id = $_GET['categorie'];
$dbh = new PDO("mysql:host=$host; dbname=$dbname;", $usernamedb,
$passworddb);
$cate = new Categorie($dbh);
$cate->loadCate($id);
// $page->loadId($id);
$categorie = $cate->getCategorie();
$titel = ucwords($categorie);
?>
<h2 class="center_h2"><?= $titel ?></h2>
<?php foreach ($cate as $key) {
$titelart = $cate->getTitel();
$beschrijving = $cate->getBeschrijving();
$plaatje = $cate->getImage();
$id = $cate->getId();
var_dump($titelart);
} ?>
<?php
} else {
echo "Dit bericht is verwijderd of is verplaats.";
}
require_once 'include/footer.php';
?>
This is my class page
<?php
class Categorie {
protected $dbh;
public function __construct($new_dbh){
$this->dbh = $new_dbh;
}
public function loadCate($cate){
$query = $this->dbh->prepare('SELECT * FROM schilderijen WHERE categorie=?');
$query->execute(array($cate));
while ($row = $query->fetch(PDO::FETCH_OBJ)) {
$this->id = $row->id;
$this->categorie = $row->categorie;
$this->titel = $row->titel;
$this->beschrijving = $row->beschrijving;
$this->plaatje = $row->plaatje;
}
}
public function getId(){
return $this->id;
}
public function getCategorie(){
return $this->categorie;
}
public function getTitel(){
return $this->titel;
}
public function getBeschrijving(){
return $this->beschrijving;
}
public function getImage(){
return $this->plaatje;
}
}
?>
Ok so you have a problem with the use of your class. In the while after your SQL request, you apply the value the instance variable like $this->id = $row->id; but this variable will be rewrite with the next row value.
Use a static function for your SQL request and return an array of Categorie like that :
class Categorie {
protected $id, $categorie, $title, $beschrijving, $plaatje;
public function __construct($id, $categorie, $title, $beschrijving, $plaatje){
$this->id = $id;
$this->categorie = $categorie;
$this->title = $title;
$this->beschrijving = $beschrijving;
$this->plaatje = $plaatje;
}
public static function loadCate($dbh, $cate){
$query = $dbh->prepare('SELECT * FROM schilderijen WHERE categorie=?');
$query->execute(array($cate));
$res = array();
while ($row = $query->fetch(PDO::FETCH_OBJ)) {
$res[] = new Categorie($row->id, $row->categorie, $row->titel, $row->beschrijving, $row->plaatje);
}
return $res;
}
public function getId(){
return $this->id;
}
public function getCategorie(){
return $this->categorie;
}
public function getTitle(){
return $this->title;
}
public function getBeschrijving(){
return $this->beschrijving;
}
public function getImage(){
return $this->plaatje;
}
}
And you can use it like that:
$categories = Categorie::loadCate($dbh, $id);
foreach($categories as $categorie){
var_dump($categorie->getTitle());
}
The method -- initially called in index.php -- redirects to another page. The problem here is that variable $logged_in isn't getting assigned a new value... which means that when the variable is used in the other page, it is read as false.
NOTE: The assignment of session 'id' and session 'type' is correct.
class Session {
public $logged_in = false;
public function login($data) {
if ($data) {
$_SESSION['id'] = $data['id'];
$_SESSION['type'] = $data['type'];
$this->logged_in = true;
}
}
}
This is a class and therefore is lost (its properties are lost) at the end of the first scripts execution and then recreated in the second in its initial state.
Classes do not live across executions of the same script or any other script.
If you wish to maintain the objects state, you will have to save the state to a file or maybe the real SESSION so you can re-hydrate the data when the second script starts
session_start();
class Session {
public function login($data) {
if ($data) {
$_SESSION['id'] = $data['id'];
$_SESSION['type'] = $data['type'];
$_SESSION['logged_in'] = true;
}
}
// getter function
public function is_logged_in()
{
// just in case check
if ( isset($_SESSION['logged_in']) ) {
return $_SESSION['logged_in'] == true;
} else {
return false;
}
}
}
Called like this
$s = new Session();
if ( ! $s->is_logged_in() ) {
header('Location: index.php');
exit;
}
To keep it away from the SESSION completely you could
class Session {
public $id;
public $type;
public $logged_in;
public function __construct()
{
if ( file_exists('my_session.txt')) {
$obj = json_decode(file_get_contents('my_session.txt'));
foreach($obj as $prop => $val) {
$this->{$prop} = $val;
}
}
}
public function __destruct()
{
file_put_contents('my_session.txt', json_encode($this));
}
public function login($data) {
if ($data) {
$this->id = $data['id'];
$this->type = $data['type'];
$this->logged_in = true;
}
}
}
$obj = new Session();
$obj->login(array('id'=>99, 'type'=>'TEST'));
print_r($obj);
$obj = null;
echo 'object nulled' . PHP_EOL;
print_r($obj);
echo ' NOTHING should be printed' . PHP_EOL;
echo 'object rehydrated' . PHP_EOL;
$obj = new Session();
print_r($obj);
create another method check_login() to re-assign the values in the new page and call it within __construct()
function __construct(){
$this->check_login();
}
public function check_login(){
if(isset($_SESSION['id']) && isset($_SESSION['type']){
$this->logged_in = true;
} else {
$this->logged_in = false;
}
}
Hy,
i started learning PHP and i created a simple MVC Style Codebase.
The Script just generates a random number and displays this numer. I also write a function to display the number shown before but it does not work. The value is empty. Can you help me out, i have no clue whats wrong and there is no php error thrown.
view.php
<?php
class View
{
private $model;
private $view;
public function __construct()
{
$this->model = new Model();
}
public function output()
{
echo 'Current Entry: ';
echo $this->model->getData();
echo '<br />';
echo 'Update';
echo '<br />';
echo 'Last';
}
public function getModel()
{
return $this->model;
}
}
controller.php
<?php
class Controller
{
private $model;
private $view;
public function __construct($view)
{
$this->view = $view;
$this->model = $this->view->getModel();
}
public function get($request)
{
if (isset($request['action']))
{
if ($request['action'] === 'update')
{
for ($i = 0; $i<6; $i++)
{
$a .= mt_rand(0,9);
}
$this->model->setData($a);
}
elseif ($request['action'] === 'preview')
{
$this->model->setLast();
}
else
{
$this->model->setData('Wrong Action');
}
}
else
{
$this->model->setData('Bad Request');
}
}
}
model.php
<?php
class Model
{
private $data;
private $last;
public function __construct()
{
$this->data = 'Default';
}
public function setData($set)
{
if ( ! (($set == 'Wrong Action') && ($set == 'Bad Request')))
{
$this->last = $this->data;
}
$this->data = $set;
}
public function getData()
{
return $this->data;
}
public function setLast()
{
$this->data = $this->last;
}
public function getLast()
{
return $this->last;
}
}
index.php
<?php
require_once 'controller.php';
require_once 'view.php';
require_once 'model.php';
$view = new View();
$controller = new Controller($view);
if (isset($_GET) && !empty($_GET)) {
$controller->get($_GET);
}
$view->output();
Are there any other, bad mistakes in the Script?
Any input very welcome! :)
The problem with your code is that PHP does not preserve variable values between requests, therefore, when you set your $model->last value here:
$this->last = $this->data;
It gets reset on your next request.
You may want to store $last value in a session or a cookie instead. Something like:
$_SESSION['last'] = $this->data;
And then when you are instantiating your model you could initialize it with a value stored in a session if available:
index.php - add session_start() at the beginning
model.php:
public function __construct()
{
$this->data = isset($_SESSION['last']) ? $_SESSION['last'] : 'Default';
}
public function setData($set)
{
$this->data = $set;
if ( ! (($set == 'Wrong Action') && ($set == 'Bad Request')))
{
$_SESSION['last'] = $this->data;
}
}
controller.php
elseif ($request['action'] === 'preview')
{
//Remove this
//$this->model->setLast();
}
I have just a little progress in practicing. Most of my code works but I am not sure if I do things the right way?
Please, can you tell me if I do mistakes and correct me.
First, I create autoload functions:
function autoload_models($model) {
if (file_exists(MODELS_PATH . $model . '.php')) {
require_once MODELS_PATH . $model . '.php';
return true;
} else {
return false;
}
}
spl_autoload_register('autoload_models');
function autoload_controllers($controller) {
if (file_exists(CONTROLLERS_PATH . $controller . '.php')) {
require_once CONTROLLERS_PATH . $controller . '.php';
return true;
} else {
return false;
}
}
spl_autoload_register('autoload_controllers');
I have a class like this:
class Category {
public $db;
public $rows;
public $id;
public function build_category() {
global $db;
global $rows;
$db = new Database();
$db->query("SELECT * from categories");
$rows = $db->resultset();
}
public function category_items() {
global $db;
global $rows;
global $id;
$db = new Database();
$db->query("SELECT * from posts WHERE category_id = '$id'");
$rows = $db->resultset();
}
}
I extend with another class (still have some issues here. Nothing prints):
class Category_Items extends Category {
public $db;
public $rows;
public $id;
public function display_category_items() {
// Call the parent class function
parent::category_items();
global $rows;
global $id;
// Check if the page parameter is integer
if (ctype_digit($_GET['id'])) {
$id = $_GET['id'];
} else {
print "Illegal category page parameter";
}
foreach ($rows as $row) {
print "test";
print $row['post_title']; // This does not work yet. Nothing prints
}
}
}
Class for building a menu with categories (Everything works here):
class Categories_Menu extends Category {
public $db;
public $rows;
public function build_category_menu() {
parent::build_category();
global $rows;
foreach ($rows as $row) {
require VIEWS_PATH . 'categories/categories_menu.php';
}
}
}
And finally instances:
$category_menu = new Categories_Menu();
$category_menu->build_category_menu();
$category_items = new Category_Items();
$category_items->display_category_items();
Thank you for your time and help!
Where do the global variables come from?
Anyway, you should get rid of them.
I guess your rows var does not get changed, after any interaction. Using globals also will not be relevant in extending classes.
Your public properties and globals mentioned, does no interact each other. Thus, the object members seems to be totally useless.
What I would suggest in simple schems would be
class Model {
protected $_db;
public function __construct(Database $db) {
$this->_db = $db;
}
}
class Category extends Model {
public $_rows;
public $_id;
public function build_category() {
$this->_db->query("SELECT * from categories");
$this->_rows = $this->_db->resultset();
}
public function category_items() {
$this->_db->query("SELECT * from posts WHERE category_id = '{$this->_id}'");
$this->_rows = $this->_db->resultset(); // here you will overwrite $_rows ?
}
class Categories_Menu extends Category {
public $_rows;
public function build_category_menu() {
$this->build_category();
foreach ($this->_rows as $row) {
require VIEWS_PATH . 'categories/categories_menu.php';
}
}
}
class Category_Items extends Category {
public $_rows;
public $_id;
public function display_category_items() {
if (ctype_digit($_GET['id'])) { // just intval it, or use is_int?
$this->_id = $_GET['id'];
} else {
print "Illegal category page parameter";
}
// You assign value to $_id, then call the function that requires it
$this->category_items();
foreach ($this->_rows as $row) {
print "test";
print $row['post_title'];
}
}
}
EDIT I've updated the question with actual code. Turns out it was not a scope issue but a stupid mistake on my part. While testing that all value were good I was really setting them to empty.
After reading the answer below I realized I have the scope figured out but had a typo in the code.
Sorry
<?php
abstract class PHPFoo_XYZ
{
protected $_postData = array();
public function processXYZ(array $postData)
{
$this->_postData = $postData;
}
protected function _checkProcessId()
{
// doing nothing
}
}
?>
<?php
require_once dirname(__FILE__) . '/../PHPFoo/XYZ.php';
class App_XYZ extends PHPFoo_XYZ
{
protected $_UserData = array();
protected $_UserId = 'notset';
protected $_UserName = '';
public $_msg = '';
public function processXYZ(array $postData)
{
$this->_postData = $postData;
$this->_getUserData();
$this->_checkProcessId();
}
protected function _checkProcessId()
{
$this->_writeLog("User Name ".$this->_UserName);
$this->_writeLog("User Id ".$this->_UserId);
// These show empty
}
public function _getUserData() {
$UserData = array();
$UserId = array();
$User_Name = array();
$msg = '';
// Get data from database
$this->_UserId = $UserId[0]['item_id'];
// Get data from database
$this->_UserName = $User_Name[0]['title'];
// Get full data
// $results = Array of values from database
foreach ($results as $key => $value) {
$UserData[$results[$key]['fielddef_id']] = $results[$key]['value'];
}
$this->_UserData = $UserData;
$this->_writeLog("USER DATA FULL");
$this->_writeLog("User Name ".$this->_UserName);
$this->_writeLog("User Id ".$this->_UserId);
$msg = '';
foreach ($this->_UserData as $k => $v) {
$msg .= "\n".$k." == ".$v;
}
$this->_writeLog("User Data\n".$msg);
// The above output is good
if($this->_UserData = '' || $this->_UserId = '' || $his->_UserName = '') {
$this->_writeLog("There was an error getting User Data.");
return false;
}else{
return true;
}
}
}
There is something wrong from beginning, you should write "public function" when you declare a function, not "public functions", and there must be the word "function" declaring a method, not just the name.
Also you are calling a method myfunc1, when it doesn't exists and you have made another mistake when you call func2 (you wrote fucn2).
So, if you fix your code, it works as you want.
Here I fixed it for you:
<?php
abstract class foo {
protected $_var1 = '';
protected $_var2 = '';
public function func1() {
#code...
}
public function func2() {
#code..
}
}
class bar extends foo {
protected $myvar1 = '';
protected $myvar2 = '';
public function myfunc() {
// do some code to fill myvar1 to be used in other functions
$this->myvar1 = 'some data';
echo "my var " . $this->myvar1;
}
public function func2() {
// do some code that uses myvar1 data
// but $this->myvarf1 is empty here why?
echo $this->myvar1;
}
public function runit() {
$this->myfunc();
$this->func2();
}
}
//requre file
$callclass = new bar;
$callclass->runit();
?>
So please be careful before asking and if you can/want use an ide like netbeans for php to avoid this mistakes.
Have a good night.