Upload Video to Facebook Page with call to action in php - facebook

Question

I am trying to upload video to facebook page as page admin with the call to action:
// Post Data
$action_call_array = array('type' => 'LEARN_MORE', 'value' => array('link' => 'http://www.google.com'));
$data = [
'title' => 'Demo Title',
'description' => 'Demo Description
http://www.google.com
http://hk.yahoo.com',
'source' => new CURLFile('video/video_1mb.mp4', 'video/mp4'),
'call_to_action' => $action_call_array,
'access_token' => FACEBOOK_PAGE_TOKEN, // MUST BE INCLUDED !!!
];
// Post Url
$post_url = 'https://graph-video.facebook.com/'.FACEBOOK_PAGE_ID.'/videos';
// CURL
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $post_url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$return = curl_exec($ch);
curl_close($ch);
// result
$j = json_decode($return);
$page_post_id = $j->id;
var_dump($return);
Without the call to action, it works. But after adding the call to action, it returns me the following error:
string(196) "{"error":{"type":"Exception","message":"No Call To Action Type was parseable. Please refer to the call to action api documentation","code":1373054,"is_transient":false,"fbtrace_id":"H9GksxYBdQx"}}"
Looks like the way I add the call to action is not correct. But I don't really know how to fix it.

Answer 1

I put the call to action into url parameter and it is working now!
// Post Data
$fb_action = 'LEARN_MORE';
$fb_action_link = 'http://www.google.com';
$action_call_array = array('type' => $fb_action, 'value' => array('link' => $fb_action_link));
$params = http_build_query(array('call_to_action' => $action_call_array));
$data = [
'title' => 'Demo Title',
'description' => 'Demo Description
http://www.google.com
http://hk.yahoo.com',
'source' => new CURLFile('video/video_1mb.mp4', 'video/mp4'),
'access_token' => FACEBOOK_PAGE_TOKEN, // MUST BE INCLUDED !!!
];
// Post Url
$post_url = 'https://graph-video.facebook.com/'.FACEBOOK_PAGE_ID.'/videos?'.urldecode($params);
// CURL
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $post_url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$return = curl_exec($ch);
curl_close($ch);
// result
$j = json_decode($return);
$page_post_id = $j->id;