Ajax reload shoping card after submit data - php

Question

I'm building a small online order system for a restaurant. My code for shoping card looks like this:
<?php
// Košarica
function ShopKosarica(){
global $link;
$UkupnoZbroj = 0;
$KosaricaSession = $_SESSION['ime'];
$rezultat = mysqli_query($link, "SELECT * FROM shop_kosarica WHERE KosaricaSession='$KosaricaSession' AND KosaricaKolicina<>0 ORDER BY KosaricaID ASC");
$num_results = mysqli_num_rows($rezultat);
if ($num_results==0){
echo "<h2><strong>Košarica je prazna</strong></h2>";
}else{
while ($redak = mysqli_fetch_array($rezultat)){
$ArtikalID = $redak['KosaricaArtikal'];
$rezultat_artikal = mysqli_query($link, "SELECT * FROM shop_artikal WHERE ArtikalID='$ArtikalID'");
$redak_artikal = mysqli_fetch_array($rezultat_artikal);
if ($redak['KosaricaVelicina']=='jumbo'){
$Cijena = $redak_artikal['ArtikalCijena2'];
} else {
$Cijena = $redak_artikal['ArtikalCijena1'];
}
$Kolicina = $redak['KosaricaKolicina'];
$Zbroj = $Cijena * $Kolicina;
$Zbroj = number_format((float)$Zbroj, 2, '.', '');
$UkupnoZbroj += $Zbroj;
$UkupnoZbroj = number_format((float)$UkupnoZbroj, 2, '.', '');
?>
<form class="ShopKosaricaBox" method="post">
<input type="hidden" id="KosaricaID" name="KosaricaID" value="<?=$redak['KosaricaID']?>">
<div class="MarginBottom15">
<input type="text" id="KosaricaKolicina" name="KosaricaKolicina" value="<?=$redak['KosaricaKolicina']?>" maxlength="2"> x <?=$redak_artikal['ArtikalNazivHr']?> (<?=$redak['KosaricaVelicina']?>) - <?=$Zbroj?> kn
</div>
<div class="right MarginBottom15">
<a onclick="ShopPromjena();">Promjeni</a> <a style="background:#c94e11;" onclick="ShopBrisanje();">Obriši</a>
</div>
<div class="clear"></div>
</form>
<script type="text/javascript">
function ShopPromjena() {
$(document).ready(function(){
var str = $(".ShopKosaricaBox").serialize();
$.ajax({
type: "POST",
url: "/funkcije?akcija=promjena&KosaricaID=<?=$redak['KosaricaID']?>",
data: str,
success: function(str){
alert( "Uspješno ste promjenili količinu!" );
}
});
return false;
});
}
function ShopBrisanje() {
$(document).ready(function(){
var str = $(".ShopKosaricaBox").serialize();
$.ajax({
type: "POST",
url: "/funkcije?akcija=brisi&KosaricaID=<?=$redak['KosaricaID']?>",
data: str,
success: function(str){
alert( "Uspješno ste obrisali jelo!" );
}
});
return false;
});
}
</script>
<?php
} ?>
<h1 class="MarginBottom25" style="font-size:25px;">Ukupno: <strong><?=$UkupnoZbroj?> kn</strong></h1>
<?php }
}
?>
And I put data in mysql via Ayax, this is the javascript:
$(document).ready(function(){
$(".ShopPonudaBox").submit(function(){
var str = $(this).serialize();
$.ajax({
type: "POST",
url: "/funkcije?akcija=dodaj",
data: str,
success: function(str){
alert( "Uspješno ste dodali jelo!" );
$('#KosaricaBox').load("/include/funkcije.php?funkcija=ShopKosarica");
return false;
}
});
return false;
});
});
and php code;
if ($_GET['akcija']=="dodaj") {
if ($_POST['KosaricaKolicina']<>0){
$KosaricaSession = $_SESSION['ime'];
$KosaricaArtikal = clean($link, $_POST['ArtikalID']);
$KosaricaKolicina = clean($link, $_POST['KosaricaKolicina']);
$KosaricaVelicina = clean($link, $_POST['KosaricaVelicina']);
$provjera = mysqli_query($link, "SELECT * FROM shop_kosarica WHERE KosaricaSession='$KosaricaSession' AND KosaricaArtikal='$KosaricaArtikal' AND KosaricaVelicina='$KosaricaVelicina'");
$num_results = mysqli_num_rows($provjera);
if ($num_results==0){
$result = mysqli_query($link, "INSERT INTO shop_kosarica (KosaricaSession, KosaricaArtikal, KosaricaKolicina, KosaricaVelicina) VALUE ('$KosaricaSession', '$KosaricaArtikal', '$KosaricaKolicina', '$KosaricaVelicina')");
//header("Location: /online-narudzba#Shop");
} else {
$redak_provjera = mysqli_fetch_array($provjera);
$KosaricaID = $redak_provjera['KosaricaID'];
$result = mysqli_query($link, "UPDATE shop_kosarica SET KosaricaKolicina=KosaricaKolicina+$KosaricaKolicina WHERE KosaricaID='$KosaricaID'");
//header("Location: /online-narudzba#Shop");
}
} else {
//header("Location: /online-narudzba#Shop");
}
}
I tried with this method I found here
$('#KosaricaBox').load("/include/funkcije.php?funkcija=ShopKosarica");
$funkcija = $_GET["funkcija"];
if ($funkcija == "ShopKosarica") {
echo ShopKosarica();
}
but keep getting errors
Notice: Undefined variable: _SESSION in
H:\Dropbox\htdocs\include\funkcije.php on line 47
Warning: mysqli_query() expects parameter 1 to be mysqli, null given
in H:\Dropbox\htdocs\include\funkcije.php on line 48

Answer 1

Add
session_start();
and connect database
at the beginning of your page before any HTML
You will have something like :
$con=mysqli_connect("localhost","xxxx","xxxx","xxxxx");
//check connection
if (mysqli_connect_errno($con))
{
echo "Failed to connect to MySQL:" . mysqli_connect_error();
}
session_start();
include("inc/incfiles/header.inc.php")?>
<html>
<head>
<meta http-equiv="Content-Type" conte...
Don't forget to remove the space you have before