PHP => $_SESSION Array only keeps last variable - php

Question

I'm building an interface for an online shop, where every item is a FORM and the BUY button is a submit,it submits the name and price of the clicked form and that data is displayed on a CONFIRM ORDER page. On that confirm order page I've created an array as follows
if (!isset($input_order_arr)) {
$input_order_arr = array();
}
After that I fetch the posted variables and push them into the array
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
if (!empty($_POST['item-title']) && !empty($_POST['item-price'])) {
$item_title = test_input($_POST['item-title']);
$item_price = test_input($_POST['item-price']);
array_push($input_order_arr,$item_title,$item_price);
}
}
$_SESSION['chosen_item'] = $input_order_arr;
*NOTE : test_input is a function that does striplashes , htmlspecialchars and htmltrim, for security purposes. (someone might edit the value of the item via the Chrome developer console? not sure if that holds any threat though)
And after that the value is displayed in a table like so
<?php if (isset($_SESSION['chosen_item'])) {
foreach ($_SESSION['chosen_item'] as $value) {
echo "<td>" . $value . "</td>";
}
} ?>
And here comes the problem.
If you order an item its price and name are displayed, but if u go back and you order another item, the previous item and its price are lost, as if its not adding new lines to the array,but replacing the old ones, or the session only saves data from one action, which wouldn't make any sense, since thats what $_SESSION is about, the code is presented with session_start(); in every page that is using the $_SESSION variable.
Main Question - Why could it be that the $_SESSION Array is losing its older inputs?

Answer 1

You could push directly into the session like this
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
if (!empty($_POST['item-title']) && !empty($_POST['item-price'])) {
array_push($_SESSION['chosen_item'],
test_input($_POST['item-title']),
test_input($_POST['item-price'])
);
}
}
//$_SESSION['chosen_item'] = $input_order_arr;
Or as your test_input() is likely doing nothing useful
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
if (!empty($_POST['item-title']) && !empty($_POST['item-price'])) {
array_push($_SESSION['chosen_item'],
$_POST['item-title'],
$_POST['item-price']
);
}
}
You might find this data easier to use later by doing
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
if (!empty($_POST['item-title']) && !empty($_POST['item-price'])) {
array_push($_SESSION['chosen_item'],
array('title' => $_POST['item-title'],
'price' => $_POST['item-price']
)
);
}
}

Answer 2

you need $_SESSION['chosen_item'][]=$input_order_arr; your overwriting the same index instead of creating new one
$_SESSION['chosen_item'][]=$input_order_arr;
Note : And also it should be moved inside the if statement .to avoid empty array storing in session

Answer 3

When you go back, you basically are setting the chosen_item array element to empty, since $input_order_arr would not contain anything when you haven't submitted a form.
You should append to the session array only if there is a nonempty $input_order_arr array:
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
if (!empty($_POST['item-title']) && !empty($_POST['item-price'])) {
$item_title = test_input($_POST['item-title']);
$item_price = test_input($_POST['item-price']);
array_push($input_order_arr,$item_title,$item_price);
$_SESSION['chosen_item'][] = $input_order_arr;
}
}