一旦拥有访问令牌，如何使用php在服务器上获取Facebook用户电子邮件

Question

I successfully got the access token from my Android app as such...

  fbbutton = (com.facebook.login.widget.LoginButton) findViewById(R.id.fbbutton);
  fbbutton.setOnClickListener(this);
  fbbutton.setReadPermissions(Arrays.asList("public_profile", "email"));
  callbackManager = CallbackManager.Factory.create();
  fbbutton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {

    @Override
    public void onSuccess(LoginResult loginResult) {
      GraphRequest request = GraphRequest.newMeRequest(loginResult.getAccessToken(), new GraphRequest.GraphJSONObjectCallback() {
        @Override
        public void onCompleted(JSONObject object, GraphResponse response) {
          if (response.getError() != null) {

          } else {

            if ((email = object.optString("email")) != null) {

            } else {
              email = object.optString("id") + "@facebook.com";
            }
            editor.putString("ftoken", AccessToken.getCurrentAccessToken().toString());
            editor.apply();
            Intent intent = new Intent(getApplicationContext(), MainActivity.class);
            startActivity(intent);
            finish();
          }
        }
      });
      Bundle parameters = new Bundle();
      parameters.putString("fields", "id, name, email"); // facebook parameters
      request.setParameters(parameters);
      request.executeAsync();

      // signed in UI
    }

I then successfully sent the access token to my server's php script.

I'm trying to get facebook to give me the user's email on the server side using the access token.

I'm trying as such...

        require_once __DIR__ . '/facebook-php-sdk-v4/src/Facebook/autoload.php';

(...)

        $fb = new Facebook\Facebook([
            'app_id' => '491680537671890',
            'app_secret' => 'abe9f51094b3d7c9edb3c28d102170a1',
            'default_graph_version' => 'v2.4'
        ]);
        fwrite($Handle, "point 1");

            $response = $fb->get('/me', $ftoken);

        //print_r($response);
        fwrite($Handle, "response:$response\n\n");
        $email = $response["email"];
        $userid = $email;
        fwrite($Handle, "email confirmed by facebook:[$email]\n\n");

But my php code only gets to "point 1". So it is failing at the $fb->get stage. What am I doing wrong? Thanks for any help.

Edit: I had forgotten to put a comma after the last array item

$fb = new Facebook\Facebook([
            'app_id' => '491680537671890',
            'app_secret' => 'abe9f51094b3d7c9edb3c28d102170a1',
            'default_graph_version' => 'v2.4',
        ]);

Now my code doesn't even get to point 1 .

Edit: Comma apparently doesn't matter but I took it out and I get to point 1 again [I was mistaken and the comma really doesn't make a difference]. But the var_dumps come up empty as I programmed below..

$ftoken = $json->ftoken;
fwrite($Handle, "ftoken:$ftoken\r\n");
$fb = new Facebook\Facebook([
    'app_id' => '491680537671890',
    'app_secret' => 'abe9f51094b3d7c9edb3c28d102170a1',
    'default_graph_version' => 'v2.4'
]);
$vardump = var_dump($fb);
fwrite($Handle, "first vardump:$vardump\n\n");

$response = $fb->get('/me?fields=id,name', $ftoken);
$vardump = var_dump($response);
fwrite($Handle, "vardump:$vardump\n\n");

Edit: #3: I implemented the following suggested code...

$ftoken = $json->ftoken;
        fwrite($Handle, "ftoken:$ftoken\r\n");
        $fb = new Facebook\Facebook([
                'app_id' => '491680537671890',
                'app_secret' => 'abe9f51094b3d7c9edb3c28d102170a1',
                'default_graph_version' => 'v2.4'
        ]);
        $fb->setDefaultAccessToken($ftoken);

        try {
            $response = $fb->get('/me');
            $userResponse = $response->getGraphUser();
        } catch(Facebook\Exceptions\FacebookResponseException $e) {
            // When Graph returns an error
            $userResponse = 'Graph returned an error: ' . $e->getMessage();
        } catch(Facebook\Exceptions\FacebookSDKException $e) {
            // When validation fails or other local issues
            $userResponse = 'Facebook SDK returned an error: ' . $e->getMessage();
        }finally{
            fwrite($Handle, "response:$userResponse\n\n");
            }

and I get ...

response:Graph returned an error: Invalid OAuth access token.

So my token seems to be the incorrect type?

Edit: #4: I went to the facebook object debug page and entered the token...

Access Token Info
App ID  xxxxxxxxxxxxxxxxx : recipes
User ID
xxxxxxxxxxxxxxxxxxxxxxxxx : Rxxn Kxxm
User last installed this app via API v2.x
Issued  1451792399 (20 hours ago)
Expires 1456976399 (in about 2 months)
Valid   True
Origin  Mobile Web Faceweb
Scopes  email, public_profile

So there shouldn't be any real problem with the token. I'm stumped.

Answer 1

You might try the following

$ftoken = $json->ftoken;
fwrite($Handle, "ftoken:$ftoken\r\n");
$fb = new Facebook\Facebook([
        'app_id' => '491680537671890',
        'app_secret' => 'abe9f51094b3d7c9edb3c28d102170a1',
        'default_graph_version' => 'v2.4'
]);
$fb->setDefaultAccessToken($ftoken);

try {
    $response = $fb->get('/me');
    $userResponse = $response->getGraphUser();
} catch(Facebook\Exceptions\FacebookResponseException $e) {
    // When Graph returns an error
    $userResponse = 'Graph returned an error: ' . $e->getMessage();
} catch(Facebook\Exceptions\FacebookSDKException $e) {
    // When validation fails or other local issues
    $userResponse = 'Facebook SDK returned an error: ' . $e->getMessage();
}finally{
    fwrite($Handle, "response:$userResponse\n\n");
}

and see what we get...

Make sure your domain is in your app settings!