Facebook SDK和PHP - 服务器端身份验证和访问

Question

I intend to create some non-interactive, server-based PHP web logic that retrieves information from Facebook. As a beginner using the Facebook SDK I have problems getting started.

Purely server based, I cannot assume that my users have Facebook accounts, so I want to retrieve the FB information for them - either using a static account or anonymously.

Using the FB dashboard I've created my App ID and App Secret, and installed the SDK facebook-php-sdk-v4-5.0.0

Now, I've trouble getting/understanding my FB access_code right (and probably more than that):

define( 'APP_NAME',         "xxxxx" ); //       
define( 'APP_ID',           "19427xxxxxxx" );
define( 'APP_VERSION',      "v2.5" );
define( 'APP_SECRET',       "8c31fxxxxxxx" );

session_start();

$fb = new Facebook\Facebook( [
  'app_id'                  => APP_ID,
  'app_secret'              => APP_SECRET,
  'default_graph_version'   => APP_VERSION,
] );

// get oauth token ??
$query = http_build_query([
     'client_id'     => APP_ID,
     'client_secret' => APP_SECRET,
     'grant_type'    => 'client_credentials',
]);

$response1 = $fb->get( '/oauth/access_token?' . $query, $fb->getApp()->getAccessToken() );  
$graph = $response1->getGraphObject();      
foreach( $graph->getPropertyNames() as $prop)
{
    echo  $prop, "=", $graph->getProperty( $prop ), "<br/>", "
";
}

$access_token = $graph->getProperty( 'access_token' );
$fb->setDefaultAccessToken( $access_token );

$request = new Facebook\FacebookRequest( $fb->getApp(), $access_token, 'GET', '/me?fields=id,name');

// Send the request to Graph
try
{
    $response = $fb->getClient()->sendRequest($request);
}
catch (Facebook\Exceptions\FacebookResponseException $e)
{
    echo 'Graph returned an error: ' . $e->getMessage();    
    // --> Invalid OAuth access token.
    // --> An active access token must be used to query information about the current user
    exit;
}

It seems I just don't get the access_code right, since whatever I do I get either "Invalid OAuth access token" or "An active access token must be used to query information about the current user"

Any insight is very much appreciated.

Update - this finally worked for me:

session_start();

$fb = new Facebook\Facebook( [
  'app_id'                  => APP_ID,
  'app_secret'              => APP_SECRET,
  'default_graph_version'   => APP_VERSION,
] );

// get oauth token ??
$query = http_build_query([
     'client_id'     => APP_ID,
     'client_secret' => APP_SECRET,
     'grant_type'    => 'client_credentials',
]);

$r_token    = $fb->get( '/oauth/access_token?' . $query, $fb->getApp()->getAccessToken() ); 
$graph= $r_token->getGraphObject();     
$a_token= $graph->getProperty( 'access_token' );
$fb->setDefaultAccessToken( $a_token );
$since = strtotime($since_date);
$until = strtotime($until_date);        
$fields=    "id,name,description,place,timezone,start_time,end_time";
$json_link= "https://graph.facebook.com/" . PAGE_ID . "/events/attending/?access_token={$a_token}&fields={$fields}&since={$since}&until={$until}";
$json = file_get_contents($json_link);      

Answer 1

This finally worked for me:

session_start();

$fb = new Facebook\Facebook( [
  'app_id'                  => APP_ID,
  'app_secret'              => APP_SECRET,
  'default_graph_version'   => APP_VERSION,
] );

// get oauth token ??
$query = http_build_query([
     'client_id'     => APP_ID,
     'client_secret' => APP_SECRET,
     'grant_type'    => 'client_credentials',
]);

$r_token    = $fb->get( '/oauth/access_token?' . $query, $fb->getApp()->getAccessToken() ); 
$graph= $r_token->getGraphObject();     
$a_token= $graph->getProperty( 'access_token' );
$fb->setDefaultAccessToken( $a_token );
$since = strtotime($since_date);
$until = strtotime($until_date);        
$fields=    "id,name,description,place,timezone,start_time,end_time";
$json_link= "https://graph.facebook.com/" . PAGE_ID . "/events/attending/?access_token={$a_token}&fields={$fields}&since={$since}&until={$until}";
$json = file_get_contents($json_link);