Getting SESSION to work after redirect - php

Question

I am new to PHP and even newer to SESSIONS
I am working with the Instagram API and I am successfully able to authorize an app, and redirect to a page to display content.
My main folder is called Monkey and it has a sub folder called Instagram.
MY callback url for instagram is success.php located in the instagram folder. When I successfully retrieve an access token from Instagram it redirects to the index file in the Monkey folder.
On my success page, I am creating an array full of data called instaArray. I am trying to pass the array from the success.php in the instagram folder, to the index.php in the monkey folder.
My redirect is simply
header( 'Location: ../index.php' );
Because I am new with sessions, I guess I am doing something wrong. I figured it was straight forward, but I suppose not ha.
On the success.php page, after I build the array I have this
session_start();
$_SESSION['instagram'] = $instaArray;
I thought that should create a session that holds my array InstaArray.
Then, on the index.php page in Monkey, I have this
<?php
session_start();
$get_instagram = $_SESSION['instagram'];
print_r($get_instagram);
?>
But absolutely nothing happens. I've even tried to set the session instagram to a simple numerical value or 1, $_SESSION['instagram'] = 1; and get that on the index page, and it doesn't work either.
Am I doing something horribly, terribly wrong? I've read up on sessions, but because it's new, it's still a little confusing.
Thanks for the help, and I hope I was able to explain everything properly.
EDIT: Here is my success.php page in full
<?php
require 'src/db.php';
require 'src/instagram.class.php';
require 'src/instagram.config.php';
// Receive OAuth code parameter
$code = $_GET['code'];
// Check whether the user has granted access
if (true === isset($code)) {
// Receive OAuth token object
$data = $instagram->getOAuthToken($code);
// Take a look at the API response
$username = $data->user->username;
$fullname = $data->user->full_name;
$id = $data->user->id;
$token = $data->access_token;
$user_id = mysql_query("select instagram_id from users where instagram_id='$id'");
if(mysql_num_rows($user_id) == 0) {
mysql_query("insert into users(instagram_username,instagram_name,instagram_id,instagram_access_token) values('$username','$fullname','$id','$token')");
}
//Set Cookie
$Month = 2592000 + time();
setcookie(instagram, $id, $Month);
// Set user access token
$instagram->setAccessToken($token);
// Retrive Data
$instaData = $instagram->getUserFeed();
// Create Instagram Array
$instaArray = array();
$count = 0;
// For each Instagram Post
foreach ($instaData->data as $post) {
$instaArray[$count]['post_id'] = $post->id;
$instaArray[$count]['name'] = $post->user->username;
$instaArray[$count]['profile_img'] = $post->user->profile-picture;
$instaArray[$count]['img_url'] = $post->images->standard_resolution->url;
$instaArray[$count]['caption'] = $post->caption->text;
$instaArray[$count]['like_count'] = $post->likes->count;
$instaArray[$count]['comment_count'] = $post->comments->count;
$instaArray[$count]['created_time'] = $post->created_time; //Unix Format
$count++;
}
// Start Session For Array
session_start();
$_SESSION['instagram'] = serialize($instaArray);
header( 'Location: ../index.php' ) ;
} else {
// Check whether an error occurred
if (true === isset($_GET['error'])) {
echo 'An error occurred: '.$_GET['error_description'];
}
}
?>

Answer 1

Why not use an ID and then cookies rather than sessions + data (which are usually store on the server in text files in a temporary directory)? And keep all data within a database than allow the client to be accessible to the data. Sessions are also temporary.
Note, do you know if you have "globals" on?!
"Please note when working with sessions that a record of a session is not created until a variable has been registered using the session_register() function or by adding a new key to the $_SESSION superglobal array. This holds true regardless of if a session has been started using the session_start() function."
Reference:
http://www.php.net/manual/en/function.session-register.php

Answer 2

make session_start() first line after php
<?php
session_start();
and remove it from anywhere ele on page.
session_start() should be your first line in index.php also as in success.php
Note: The session_start() function must appear BEFORE the tag:
REF : http://www.w3schools.com/php/php_sessions.asp

Answer 3

I think you need to unserialize() your array in index.php.
$get_instagram = unserialize($_SESSION['instagram']);