Retrieving list of items using php - php

Question

I am trying to retrieve a list of items from a mySQL db and insert them as a list in a select object on a webpage. The following is the bit of code that isnt working.
In the first line, I am trying to retrieve a JSON object from a public function called getBrands() in a singleton object I have created called DatabaseInterface.
The second line is then attempting to turn that JSON object into a php array.
Finally, I am running a loop which can option each item in between tags for the webpage.
Where am I going wrong?
<?php
var $brandArrayJSON = DatabaseInterface::getBrands();
$brandArray = JSON_decode($brandArrayJSON);
for ($loop=0; $loop < sizeof($brandArray); $loop++) {
echo "<option>$brandArray[$loop]</option>";
}
?>
EDIT: In case it helps, here is my DatabaseInterface singleton. I have included this file at the top of my php file
class databaseInterface {
private static $_instance;
// Private constructor prevents instantiation
private function __construct() {
}
public static function getInstance() {
if (!self::$_instance) {
self::$_instance = mysqli_connect(self::databaseHost, self::databaseUsername, self::databasePassword, self::databaseName);
if (mysqli_connect_errno(self::$_instance)) {
throw new Exception("Failed to connect to MySQL:" . mysqli_connect_error());
}
}
return self::$_instance;
}
public function getBrands() {
try {
$con = DatabaseInterface::getInstance();
} catch (Exception $e) {
// Handle exception
echo $e->getMessage();
}
$query = "SELECT psBrandName from brands";
$result = mysqli_query($con, $query) or die ("Couldn't execute query. ".mysqli_error($con));
$resultArray[] = array();
while ($row = mysqli_fetch_assoc($result)) {
extract($row);
$resultArray[] = $psBrandName;
}
return json_Encode($resultArray);
}

Answer 1

There is nothing "wrong" with the code, in that it should work (provided nothing is broken on the query-side). However, there are several things that should be improved.
First, basically what the getBrands() method is doing is equivalent to this:
$brandArray = json_encode(array('test','test2','test3'));
echo $brandArray; // returns ["test","test2","test3"]
Now, when you decode that you get the same thing you originally put in (an array):
$brandArray = json_decode('["test","test2","test3"]');
var_dump($brandArray); // Will dump an array
Since this is an array (not a PHP object), you can just use a foreach.
foreach($brandArray as $option) {
echo '<option>', $option, '</option>';
}
If you're worried about it being an object in some instances (maybe you had a non-array JS object which would be mostly the equivalent to a PHP associative array), you could cast the json_decode result into an array.
$brandArray = (array)$brandArray;
Now, in your getBrands() method, I would highly recommend just using $row['psBrandName'] instead of cluttering things up with extract, unless you have a really good reason to do this.