How to retrive multiple url parameter in php - php

Question

I have 4 parameter in my URL. I retrieve the url parameter from my url that is given. With every parameter I'm changing the path to a directory and get different images.
My sample url look like this:
www.sample.com?cat=section1&language=de&prices=pl
The code is working but it's a spagheti code.
Is there a solution to make is less DRY ? How do I retrieve multiple url parameter ?
if(isset($_GET["cat"])) {
switch ($cat) {
case 'section1':
if(isset($_GET["language"])) {
$language = htmlspecialchars($_GET["language"]);
if($language == "de") {
if(isset($_GET["prices"])) {
$prices = htmlspecialchars($_GET["prices"]);
if($prices == "pl"){
$files=glob('pages/section1/dp/low/*.jpg');
}
else {
$files=glob('pages/section1/dn/low/*.jpg');
}
}
else {
$files=glob('pages/section1/dn/low/*.jpg');
}
}
elseif ($language == "en") {
if(isset($_GET["prices"])) {
$prices = htmlspecialchars($_GET["prices"]);
if($prices == "pl"){
$files=glob('pages/section1/ep/low/*.jpg');
}
else {
$files=glob('pages/section1/en/low/*.jpg');
}
}
else {
$files=glob('pages/section1/en/low/*.jpg');
}
}
elseif ($language == "cz") {
if(isset($_GET["prices"])) {
$prices = htmlspecialchars($_GET["prices"]);
if($prices == "pl"){
$files=glob('pages/section1/cp/low/*.jpg');
}
else {
$files=glob('pages/section1/cn/low/*.jpg');
}
}
else {
$files=glob('pages/section1/cn/low/*.jpg');
}
}
else {
$files=glob('pages/section1/cn/low/*.jpg');
}
}
else {
$files=glob('pages/section1/dn/low/*.jpg');
}
break;
case 'section2':
//the same like in section 1, path is .../section2/...
break;
case section3:
//the same like in section 1, path is .../section3/...
break;
default:
//the same like in section 1
break;
}
else {
//the same like in section 1
}
The path d=german, e=english, c=czech, p=prices, n=noprices

Answer 1

You could shorten/remove many if else statements with just doing the checks:
$lang_code = $language[0];
There you have your first letter, you can do the same with every GET parameter.
So you can use that as in:
$files=glob('pages/section1/'.$lang_code.'p/low/*.jpg');
You can do the same for everything else.
P.s.: don't forget to sanitze any user input i.e.:
$language=mysqli_real_escape_string($conn, $_GET['language']);

Answer 2

I'd probably do something like this:
<?php
$allowedCat = ['section1', 'section2'];
$allowedLanguage = ['pl', 'en', 'cz'];
$allowedPrice = ['pl', '??'];
$cat = (isset($_GET["cat"])) ? $_GET["cat"] : null;
$language = (isset($_GET["language"])) ? $_GET["language"] : null;
$prices = (isset($_GET["prices"])) ? $_GET["prices"] : null;
if (!in_array($cat, $allowedCat)) throw new \Exception('Invalid `cat`');
if (!in_array($language, $allowedLanguage)) throw new \Exception('Invalid `language` option.');
if (!in_array($prices, $allowedPrice)) throw new \Exception('Invalid `price` option.');
$someVar1 = ($prices === 'pl') ? 'p' : 'n';
$someVar2 = $language[0];
$files = glob("pages/{$cat}/{$someVar1}{$someVar2}/low/*.jpg");
Think that should be self explanatory. Translates one to one really. Was not certain on how the other price option was specified...