How to auto publish post on Facebook Fan Page as admin using Facebook PHP SDK V4 Graph API v2.2 (3) - Single Product Manual Posting

Note: Check out the sample code at bottom of this article.

<?php
session_start();
define('FACEBOOK_SDK_V4_SRC_DIR', __DIR__ . '/Facebook/');
require __DIR__ . '/Facebook/autoload.php';

// use Facebook/autoload.php;
use Facebook\FacebookSession;
use Facebook\FacebookRequest;
use Facebook\GraphUser;
use Facebook\FacebookRequestException;
use Facebook\FacebookRedirectLoginHelper;

// Product information
$name = '< Product Name >';
$link = '< Product URL >';
$picture = 'http://<image url >';
$caption = '< Webstore Slogan > ';
$message = '< Product Short Description or anything >';

// Facebook App related
$api_key = '< APP Id >';
$api_secret = '< APP Secret >';
$accessToken='< Facebook Page Access Token>';
$page_id = '< Facebook Page Id >';

// start a session for this App
FacebookSession::setDefaultApplication($api_key, $api_secret);
$session = new FacebookSession($accessToken);

// Auto posting
$page_post = (new FacebookRequest( $session, 'POST', '/'. $page_id .'/feed', array(
    'access_token' => $access_token,
    'name' => $name,
    'link' => $link,
	'picture' => $image,
    'caption' => $caption,
    'message' => $message,
  ) ))->execute()->getGraphObject()->asArray();

// return post_id, optional
print_r( $page_post );

?>

The code is quite simple. First, we need to define the path to facebook php sdk files, as well as path to autoloader.php.

define('FACEBOOK_SDK_V4_SRC_DIR', __DIR__ . '/Facebook/');
require __DIR__ . '/Facebook/autoload.php';

Because autoloader is used, we can just use the keyword "use" to import the namespace and necessary files automatically.

use Facebook\FacebookSession;
use Facebook\FacebookRequest;
use Facebook\GraphUser;
use Facebook\FacebookRequestException;
use Facebook\FacebookRedirectLoginHelper;

These are product information that going for facebook page posting. The next step is to retrieve product information from database. For now, we just supply the information manually.

$name = '< Product Name >';
$link = '< Product URL >';
$picture = 'http://<image url >';
$caption = '< Webstore Slogan > ';
$message = '< Product Short Description or anything >';

These are Facebook App information created from last two articles.

$api_key = '< APP Id >';
$api_secret = '< APP Secret >';
$accessToken='< Facebook Page Access Token>';
$page_id = '< Facebook Page Id >';

Setting session using Facebook App ID, Secret and permanent Page Access Token..

FacebookSession::setDefaultApplication($api_key, $api_secret);
$session = new FacebookSession($accessToken);

This is the code that put everything together and post on facebook page remotely.

$page_post = (new FacebookRequest( $session, 'POST', '/'. $page_id .'/feed', array(
    'access_token' => $access_token,
    'name' => $name,
    'link' => $link,
	'picture' => $image,
    'caption' => $caption,
    'message' => $message,
  ) ))->execute()->getGraphObject()->asArray();

Here is the sample output seen by your followers:

The product description is scraped by Facebook and displayed at the line between $name and $caption. When users click at the picture or message, facebook will redirect them to your product detail page specified by $link.

Next is to integrate this piece of code with Opencart database and run under daily cron job for autoposting. 

Code:

<?php
session_start();
define('FACEBOOK_SDK_V4_SRC_DIR', __DIR__ . '/Facebook/');
require __DIR__ . '/Facebook/autoload.php';

// use Facebook/autoload.php;
use Facebook\FacebookSession;
use Facebook\FacebookRequest;
use Facebook\GraphUser;
use Facebook\FacebookRequestException;
use Facebook\FacebookRedirectLoginHelper;

// Product information
$name = '< Product Name >';
$link = '< Product URL >';
$picture = 'http://<image url >';
$caption = '< Webstore Slogan > ';
$message = '< Product Short Description or anything >';

// Facebook App related
$api_key = '< APP Id >';
$api_secret = '< APP Secret >';
$accessToken='< Facebook Page Access Token>';
$page_id = '< Facebook Page Id >';

// start a session for this App
FacebookSession::setDefaultApplication($api_key, $api_secret);
$session = new FacebookSession($accessToken);

// Auto posting
$page_post = (new FacebookRequest( $session, 'POST', '/'. $page_id .'/feed', array(
    'access_token' => $access_token,
    'name' => $name,
    'link' => $link,
	'picture' => $image,
    'caption' => $caption,
    'message' => $message,
  ) ))->execute()->getGraphObject()->asArray();

// return post_id, optional
print_r( $page_post );

?>