asked on

Facebook SDK - Login

Hello

I need to make a simple html window that will check if an access token is valid and the app has the required permissions or else it will display the a facebook login screen and ask for the required permissions for the app and then return a access token (site must not redirect!)
The access token will later be used to get friend information and so on.

I can't seem to get this to work, if somebody could help me out with this, I would be grateful.
Because site must not redirect is because I will be using this in a Flex app, the HTML file will be local and if facebook wants to redirect back it, will not be able to redirect back to a local path.

leakim971

Could you post your code?
It's all about theses three functions :

function bCheckTokenValid(token) {
    // code
    return TrueOrFalse; // a boolean
}

functions sGetCurrentToken() {
   // code
   return token; // a string
}

function sDisplayFacebookLoginScreenWhichRequestPermission() {
   // code
   return token; // a string
}

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JoachimPetersen

ASKER

The reason for me to write here was because the code from facebook site did not even work:
see their example code here:
https://developers.facebook.com/docs/opengraph/getting-started/
That code is not working, here is my app ID, so you don't need to create a app in facebook yourselfs: App Id: 306529702749085

leakim971

no, their code really work, it used by million of developers... let me do a correction, billion of developers :)

JoachimPetersen

ASKER

try and run the 'official' example and replace the 'replace me' with '306529702749085'
Then tell me if it is working.

leakim971

JoachimPetersen

ASKER

Well mine do not display the login button, it might be my browser settings then.
Anyway, that is the code I have so far, the problem is that I need the login to be embedded in the page as StageWebView in Flex does not support popup and a local file return to facebook oauth is not possible (https://www.facebook.com/dialog/oauth?client_id=AppID&redirect_uri=ALocalPathIsNotPossibleHereSoFarIKnow&response_type=token))
So the facebook login has to be embedded in the local page.

leakim971

So you need to do the work on the server side

JoachimPetersen

ASKER

So there is no solution to embed the facebook login to your own page? like define a div an it creates a facebook login area?
(client-sided with javascript)

leakim971

with no popup no

JoachimPetersen

ASKER

I am then forced to make the file on a server then, I found this PHP script and is what I am looking for, the problem is that I do not know PHP and javascript very well, so I would need some help to translate this into javascript:

<?php
  $app_id = "YOUR_APP_ID";
  $app_secret = "YOUR_APP_SECRET"; 
  $my_url = "YOUR_POST_LOGIN_URL";
     
  // known valid access token stored in a database 
  $access_token = "YOUR_STORED_ACCESS_TOKEN";

  $code = $_REQUEST["code"];
    
  // If we get a code, it means that we have re-authed the user 
  //and can get a valid access_token. 
  if (isset($code)) {
    $token_url="https://graph.facebook.com/oauth/access_token?client_id="
      . $app_id . "&redirect_uri=" . urlencode($my_url) 
      . "&client_secret=" . $app_secret 
      . "&code=" . $code . "&display=popup";
    $response = file_get_contents($token_url);
    $params = null;
    parse_str($response, $params);
    $access_token = $params['access_token'];
  }

        
  // Attempt to query the graph:
  $graph_url = "https://graph.facebook.com/me?"
    . "access_token=" . $access_token;
  $response = curl_get_file_contents($graph_url);
  $decoded_response = json_decode($response);
    
  //Check for errors 
  if ($decoded_response->error) {
  // check to see if this is an oAuth error:
    if ($decoded_response->error->type== "OAuthException") {
      // Retrieving a valid access token. 
      $dialog_url= "https://www.facebook.com/dialog/oauth?"
        . "client_id=" . $app_id 
        . "&redirect_uri=" . urlencode($my_url);
      echo("<script> top.location.href='" . $dialog_url 
      . "'</script>");
    }
    else {
      echo "other error has happened";
    }
  } 
  else {
  // success
    echo("success" . $decoded_response->name);
    echo($access_token);
  }

  // note this wrapper function exists in order to circumvent PHP’s 
  //strict obeying of HTTP error codes.  In this case, Facebook 
  //returns error code 400 which PHP obeys and wipes out 
  //the response.
  function curl_get_file_contents($URL) {
    $c = curl_init();
    curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($c, CURLOPT_URL, $URL);
    $contents = curl_exec($c);
    $err  = curl_getinfo($c,CURLINFO_HTTP_CODE);
    curl_close($c);
    if ($contents) return $contents;
    else return FALSE;
  }
?>

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So far, the translation of the script to javascript is:

  var app_id = "**********";
  var app_secret = "********"; 
  var my_url = "************/faceauth.html";
     
  // known valid access token stored in a database 
  var access_token = "AOldFaceBookToken";
// get the token like this for testing: https://www.facebook.com/dialog/oauth?client_id=APPID&redirect_uri=************/faceauth.html&response_type=token
  var code = var _REQUEST["code"];
    
  // If we get a code, it means that we have re-authed the user 
  //and can get a valid access_token. 
  if ((code)) {
    var token_url="https://graph.facebook.com/oauth/access_token?client_id="
       + "" +  app_id  + "" +  "&redirect_uri="  + "" +  urlencode(my_url) 
       + "" +  "&client_secret="  + "" +  app_secret 
       + "" +  "&code="  + "" +  code  + "" +  "&display=popup";
    var response = file_get_contents(token_url);
    var params = null;
    parse_str(response, params);
    access_token = params['access_token'];
  }

  // Attempt to query the graph:
  var graph_url = "https://graph.facebook.com/me?"
     + "" +  "access_token="  + "" +  access_token;
  response = curl_get_file_contents(graph_url);
  var decoded_response = json_decode(response);
    
  //Check for errors 
  if (decoded_response.error) {
  // check to see if this is an oAuth error:
    if (decoded_response.error.type== "OAuthException") {
      // Retrieving a valid access token. 
      var dialog_url= "https://www.facebook.com/dialog/oauth?"
         + "" +  "client_id="  + "" +  app_id 
         + "" +  "&redirect_uri="  + "" +  urlencode(my_url);
      alert(("<script> top.location.href='"  + "" +  dialog_url 
       + "" +  "</script>"));
    }
    else {
      alert( "other error has happened");
    }
  } 
  else {
  // success
    alert(("success"  + "" +  decoded_response.name));
    alert((access_token));
  }

  // note this wrapper function exists in order to circumvent PHP’s 
  //strict obeying of HTTP error codes.  In this case, Facebook 
  //returns error code 400 which PHP obeys and wipes out 
  //the response.
  function curl_get_file_contents (URL) {
    var c = curl_init();
    curl_setopt(c, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt(c, CURLOPT_URL, URL);
    var contents = curl_exec(c);
    var err  = curl_getinfo(c,CURLINFO_HTTP_CODE);
    curl_close(c);
    if (contents) return contents;
    else return false;
  }

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leakim971

when I say it's not possible to do it without :
- server side
- popup

I don't see why translating (IF POSSIBLE) php code to JS code will allow it doable...
No, you should use server side code if you CAN'T use the popup version facebook give you.

JoachimPetersen

ASKER

I understand but above provided script checks the response from oauth (client side)
Then to display login, I use oauth again and have the above code the file on a webserver, provide the oauth return url to the webserver file.

JoachimPetersen

ASKER

What I am saying:

www.example.com/Myfile.html --> checks token provided ---> if no token ---> redirect to https://www.facebook.com/dialog/oauth with returnurl to www.example.com/Myfile.html
if token is working then it will call a as3 function

so I need the script as that would be the way to go with the information you have provided to me so far.

leakim971

so why people are using server side if they just can do it client side?

JoachimPetersen

ASKER

The facebook oauth does the server sided function, then it returns what I asked for in request, then I simply handle it.

ASKER CERTIFIED SOLUTION

leakim971

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JoachimPetersen

ASKER

No the points goes to the solution, what I asked for was not possible as you pointed out so you answered my question, I just wanted to write a complete solution as I could so other people would see the solution to this if they found this post.

So what I am going to do is use oauth insted of using facebook sdk javascript to avoid the popup window.