Get like data off of Facebook

Question

I need to write a php program to get data from Facebook and since I am new to this I am just trying it out on my own Facebook right now. Anyways I found a tutorial online using PHP SDK v5 to get this data and I am trying to implement some of the code they have for getting like/data/posts/photo info from Facebook. But I am a little confused about a few parts of the program. For one part of the program is to login to my website, but I do not have a website or anything like that I just need to the program to access my Facebook and return all the like data and so forth. I might not be understanding something about this or possibly this is not the right approach to this maybe? Or maybe that part where I put my website is that where I put my Facebook URL because I have not put my Facebook URL in the program at all.

<?php
session_start();
require_once __DIR__ . '/src/Facebook/autoload.php'; // download official fb sdk for php @ https://github.com/facebook/php-graph-sdk
$fb = new Facebook\Facebook([
  'app_id' => '610350886153182',
  'app_secret' => '812a753d0cc8daeb843a2f07d97d6d50',
  'default_graph_version' => 'v3.3'
  ]);
$helper = $fb->getRedirectLoginHelper();
// app directory could be anything but website URL must match the URL given in the developers.facebook.com/apps
define('APP_URL', 'http://sohaibilyas.com/fbapp/'); // RIGHT HERE, DO NOT KNOW WHAT THIS IS FOR
$permissions = ['user_posts', 'user_photos']; // optional
try {
    if (isset($_SESSION['facebook_access_token'])) {
        $accessToken = $_SESSION['facebook_access_token'];
    } else {
        $accessToken = $helper->getAccessToken();
    }
} catch(Facebook\Exceptions\FacebookResponseException $e) {
    // When Graph returns an error
    echo 'Graph returned an error: ' . $e->getMessage();
    exit;
} catch(Facebook\Exceptions\FacebookSDKException $e) {
    // When validation fails or other local issues
    echo 'Facebook SDK returned an error: ' . $e->getMessage();
    exit;
 }
if (isset($accessToken)) {
    if (isset($_SESSION['facebook_access_token'])) {
        $fb->setDefaultAccessToken($_SESSION['facebook_access_token']);
    } else {
        // getting short-lived access token
        $_SESSION['facebook_access_token'] = (string) $accessToken;
        // OAuth 2.0 client handler
        $oAuth2Client = $fb->getOAuth2Client();
        // Exchanges a short-lived access token for a long-lived one
        $longLivedAccessToken = $oAuth2Client->getLongLivedAccessToken($_SESSION['facebook_access_token']);
        $_SESSION['facebook_access_token'] = (string) $longLivedAccessToken;
        // setting default access token to be used in script
        $fb->setDefaultAccessToken($_SESSION['facebook_access_token']);
    }
    // redirect the user back to the same page if it has "code" GET variable
    if (isset($_GET['code'])) {
        header('Location: ./');
    }
    // validating user access token
    try {
        $user = $fb->get('/me');
        $user = $user->getGraphNode()->asArray();
    } catch(Facebook\Exceptions\FacebookResponseException $e) {
        // When Graph returns an error
        echo 'Graph returned an error: ' . $e->getMessage();
        session_destroy();
        // if access token is invalid or expired you can simply redirect to login page using header() function
        exit;
    } catch(Facebook\Exceptions\FacebookSDKException $e) {
        // When validation fails or other local issues
        echo 'Facebook SDK returned an error: ' . $e->getMessage();
        exit;
    }
    // getting likes data of recent 100 posts by user
    $getPostsLikes = $fb->get('/me/posts?fields=likes.limit(1000){name,id}&limit=100');
    $getPostsLikes = $getPostsLikes->getGraphEdge()->asArray();
    // printing likes data as per requirements
    foreach ($getPostsLikes as $key) {
        if (isset($key['likes'])) {
            echo count($key['likes']) . '<br>';
            foreach ($key['likes'] as $key) {
                echo $key['name'] . '<br>';
            }
        }
    }
    // getting likes data of recent 100 photos by user
    $getPhotosLikes = $fb->get('/me/photos?fields=likes.limit(1000){name,id}&limit=100&type=uploaded');
    $getPhotosLikes = $getPhotosLikes->getGraphEdge()->asArray();
    // printing likes data as per requirements
    foreach ($getPhotosLikes as $key) {
        if (isset($key['likes'])) {
            echo count($key['likes']) . '<br>';
            foreach ($key['likes'] as $key) {
                echo $key['name'] . '<br>';
            }
        }
    }
    // Now you can redirect to another page and use the access token from $_SESSION['facebook_access_token']
} else {
    // replace your website URL same as added in the developers.facebook.com/apps e.g. if you used http instead of https and you used non-www version or www version of your website then you must add the same here
//ALSO HERE, SOMETHING ABOUT LOGGING IN TO WEBSITE BUT I DO NOT KNOW WHAT THAT IS NECESSARY
    $loginUrl = $helper->getLoginUrl(APP_URL, $permissions);
    echo '<a href="' . $loginUrl . '">Log in with Facebook!</a>';

Answer 1

That URL is the URL where you implemented FB Login. The codes uses the redirect helper which means it does not render a oAuth URL itself but uses the Login button/JS SDK for it.

See https://developers.facebook.com/docs/php/FacebookRedirectLoginHelper/5.0.0 or the official example here https://developers.facebook.com/docs/php/howto/example_access_token_from_javascript