FacebookSDK search by username/pagename - php

Question

I'm trying to access public information for a user based on their username/pagename.
I'm doing this:
$uname = 'csga5000';
$session = new Facebook\Facebook([
'app_id' => self::$FACEBOOK_APP_ID,
'app_secret' => self::$FACEBOOK_APP_SECRET,
'default_graph_version' => 'v2.2'
]);
try {
// Returns a `Facebook\FacebookResponse` object
$response = $session->get('/search?q='+$uname+'&type=user');
} catch(Facebook\Exceptions\FacebookResponseException $e) {
print_r($e);
echo 'Graph returned an error: ' . $e->getMessage();
exit;
} catch(Facebook\Exceptions\FacebookSDKException $e) {
echo 'Facebook SDK returned an error: ' . $e->getMessage();
exit;
}
But the exception is thrown, here is the output:
Graph returned an error: (#803) Some of the aliases you requested do not exist: v2.20
Alternatively(Got this from looking at the source code)
$response = $session->sendRequest('GET','/search',['q'=>$uname,'type'=>'user']);
Returns "Graph returned an error: An access token is required to request this resource." I stole a reference from somewhere using app id and secret as the token in this format:
$response = $session->sendRequest('GET','/search',['q'=>$uname,'type'=>'user'], self::$FACEBOOK_APP_ID.'|'.self::$FACEBOOK_APP_SECRET);
This throws: "Graph returned an error: A user access token is required to request this resource."
I don't understand why a USER access token is required :/
Anyone know how to search for a user based on username in php? I've seen other examples that were slightly outdated, but I was pretty much the same as what they claim worked.
Edit:
The information we want to acquire is primarily follower count.

Answer 1

First of all, you can´t search for users by username anymore. Earlier this was possible by just using a simple API call: graph.facebook.com/username
This does not work anymore, and the Search API only allows to search for the name (first/last). You are not supposed to use the username anymore.
That being said, you need to authorize yourself and use a User Token, as the error message tells you. That´s just how it is, and you can read it in the docs too:
Searches across Page and Place objects requires an app access token.
All other endpoints require a user access token.
Source: https://developers.facebook.com/docs/graph-api/using-graph-api/v2.4#search
More information about Tokens:
https://developers.facebook.com/docs/facebook-login/access-tokens
http://www.devils-heaven.com/facebook-access-tokens/

Answer 2

It seems to be the case that it's not possible(at the time) to access more than a user's name publicly. OAuth is required to access the public profile (which is a default permission).
Using the graph api explorer you can verify this using the endpoint /{user-id} and trying to get additional information for a user with whatever id.
The return is like this:
{
"name": "John Doe",
"id": "100003216243221"
}
You can get first and last name as well, by appending:
?fields=name,first_name,last_name
But access to other information fails, even when public. (I only tested location, which clearly has an additional permission).
EDIT!
HOWEVER:
If you wish to access a facebook page, some information is accessible.
This is some of the information returned if no fields are specified: about, id, can_post, category, check_ins, has_added_app, is_community_page, is_published, likes, link, location, name, phone, talking_about_count, username, website, were_here_count.
Using the endpoint:
{page-username-or-id}?fields=engagement,is_permanently_closed,emails,picture
Can retrieve other information fields (assuming they're public).
So code for this:
Facebook sdk v4:
$session = FacebookSession::newAppSession();
$session->validate();
$ret = new FacebookRequest(
$session, 'GET', '/'.$uname.'?fields=name,engagement,phone,link,is_community_page,is_permanently_closed,influences,hometown,general_info,emails,bio,birthday,description,location,username,likes,picture'
);
$ret = $ret->execute()->getGraphObject()->asArray();
If you want to catch exceptions, you can look the thrown exceptions up: https://developers.facebook.com/docs/php/
This works for the same request for facebook sdk v5 (though, I don't know that the way I called send request is advised):
$uname = 'tbdsolutions5000';
$session = new Facebook\Facebook([
'app_id' => self::$FACEBOOK_APP_ID,
'app_secret' => self::$FACEBOOK_APP_SECRET,
'default_graph_version' => 'v2.2'
]);
try {
$response = $session->sendRequest('GET','/'.$uname,[
//Optionally:
//'fields' => 'comma, separated, fields'
],
self::$FACEBOOK_APP_ID.'|'.self::$FACEBOOK_APP_SECRET
);
} catch(Facebook\Exceptions\FacebookResponseException $e) {
print_r($e);
echo 'Graph returned an error: ' . $e->getMessage();
exit;
} catch(Facebook\Exceptions\FacebookSDKException $e) {
echo 'Facebook SDK returned an error: ' . $e->getMessage();
exit;
}
$response = $response->getGraphObject()->asArray();