[facebook] facebook: permanent Page Access Token?

Another PHP answer to make lives easier. Updated for Facebook Graph API 2.9 . Just fill 'er up and load.

<?php
$args=[
/*-- Permanent access token generator for Facebook Graph API version 2.9 --*/
//Instructions: Fill Input Area below and then run this php file
/*-- INPUT AREA START --*/
    'usertoken'=>'',
    'appid'=>'',
    'appsecret'=>'',
    'pageid'=>''
/*-- INPUT AREA END --*/
];
echo 'Permanent access token is: <input type="text" value="'.generate_token($args).'"></input>';
function generate_token($args){
    $r=json_decode(file_get_contents("https://graph.facebook.com/v2.9/oauth/access_token?grant_type=fb_exchange_token&client_id={$args['appid']}&client_secret={$args['appsecret']}&fb_exchange_token={$args['usertoken']}")); // get long-lived token
    $longtoken=$r->access_token;
    $r=json_decode(file_get_contents("https://graph.facebook.com/v2.9/me?access_token={$longtoken}")); // get user id
    $userid=$r->id;
    $r=json_decode(file_get_contents("https://graph.facebook.com/v2.9/{$userid}?fields=access_token&access_token={$longtoken}")); // get permanent token
    if($r->id==$args['pageid']) $finaltoken=$r->access_token;
    return $finaltoken;
}
?>

Addendum: (alternative)

Graph 2.9 onwards , you can skip much of the hassle of getting a long access token by simply clicking Extend Access Token at the bottom of the Access Token Debugger tool, after having debugged a short access token. Armed with information about pageid and longlivedtoken, run the php below to get permanent access token.

<?php
$args=[
/*-- Permanent access token generator for Facebook Graph API version 2.9 --*/
//Instructions: Fill Input Area below and then run this php file
/*-- INPUT AREA START --*/
    'longlivedtoken'=>'',
    'pageid'=>''
/*-- INPUT AREA END --*/
];
echo 'Permanent access token is: <input type="text" value="'.generate_token($args).'"></input>';
function generate_token($args){
$r=json_decode(file_get_contents("https://graph.facebook.com/v2.9/{$args['pageid']}?fields=access_token&access_token={$args['longlivedtoken']}"));
return $r->access_token;
}
?>

Although the second code saves you a lot of hassle, I recommend running the first php code unless you are in a lot of hurry because it cross-checks pageid and userid. The second code will not end up working if you choose user token by mistake.

Thanks to dw1 and Rob