Like button to a page photo - php

Question

Can you tell me with steps how can I do a like button in my site (php) to like a page photo on facebook?
I know that I have to use the GRAPH API and have to do the POST via HTTP to /likes .. but I dont know how can I do it with PHP code.
Somebody have an example?
Thank you

Answer 1

As long as you have obtained the publish_stream permission from the user you can like any photo you need to. If you are attempting to like the photo as a page be sure you have an access_token for the page (obtained via the /accounts connection on the user account).
Once you have the access token the like is as simple as issuing an HTTP POST to a URL that looks similar to this:
https://graph.facebook.com/PHOTO_ID/likes?access_token=ACCESS_TOKEN
Photo_ID = Photo ID in Facebook
Access_Token = Access token obtained from Facebook with the publish_stream permission.
UPDATE
PHP Sample Code based on PHP Form CURL Post
<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://graph.facebook.com/PHOTO_ID/likes");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, true);
$data = array(
'Access_Token' => 'token_value'
);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
$output = curl_exec($ch);
$info = curl_getinfo($ch);
curl_close($ch);
I would check this though as I'm not sure how accurate it is since I don't normally code PHP. In any manner, the post should be a raw HTTP POST request.

Answer 2

Fabio here is the php post snippet that i was able to get working. Snippet includes a curl to get application access token and the api post to like an object, in this case a post on my app.
The Sample post is here: Shows the post to be liked
https://shawnsspace.com/plugins/TimeLinePost.php?pageid=135669679827333&postid=135669679827333_151602784936066&type=feed&fh=750
The Like Page is here: Should Return whether the user likes or not, or login if not connected.
https://shawnsspace.com/plugins/TheLike.php?postid=135669679827333_151602784936066
Getting the Application Access Token.
function GetCH(){
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://graph.facebook.com/oauth/access_token?client_id=YOUR_APP_ID&client_secret=YOUR_APP_SECRET&grant_type=client_credentials");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
curl_setopt($ch,CURLOPT_CONNECTTIMEOUT_MS,20000);
if(substr($url,0,8)=='https://'){
// The following ensures SSL always works. A little detail:
// SSL does two things at once:
// 1. it encrypts communication
// 2. it ensures the target party is who it claims to be.
// In short, if the following code is allowed, CURL won't check if the
// certificate is known and valid, however, it still encrypts communication.
curl_setopt($ch,CURLOPT_HTTPAUTH,CURLAUTH_ANY);
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,false);
}
$sendCH = curl_exec($ch);
curl_close($ch);
return $sendCH;
};
$app_access_token = GetCH();
Looking in url for postid parameter then liking id
if($_GET['postid']){
$postid = $_GET['postid'];
}else{
$postid = '135669679827333_151602784936066';
}
if($user){
$pageLike = $facebook->api('/'.$postid.'/likes?access_token='.$access_token.'&method=post', 'POST');
}

Answer 3

You can get permissions by building an array of perms for login url. below i am requesting read_stream,publish_stream,publish_actions,offline_access in the scope for permissions.
NOTE: app access token needed for logout url.
<?php
$url = (!empty($_SERVER['HTTPS'])) ? 'https://'.$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'] : 'http://'.$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
require './src/facebook.php';
$facebook = new Facebook(array(
'appId' => 'APPID',
'secret' => 'APP-SECRET',
'cookie' => true, // enable optional cookie support
));
$user = $facebook->getUser();
if ($user) {
try {
// Proceed knowing you have a logged in user who's authenticated.
$user_profile = $facebook->api('/me');
//$pageInfo = $facebook->api('/'.$pageid.'?access_token='.$_SESSION['fb_112104298812138_access_token].');
//$pageInfoUser = $user_profile[id];
} catch (FacebookApiException $e) {
error_log($e);
$user = null;
}
}
/* */
if ($user) {
$logoutUrl = $facebook->getLogoutUrl();
} else {
$params = array(
scope => 'read_stream,publish_stream,publish_actions,offline_access',
redirect_uri => $url
);
$loginUrl = $facebook->getLoginUrl($params);
}
$access_token = $_SESSION['fb_135669679827333_access_token'];
?>
<?php
if(!$user){
echo ' : Login ';
}else{
echo 'Logout';
}
?>