How can my facebook application post message to a wall?

Question

i already found out how to post something to a wall with the graph api on behalf of the facebook user. But now i want to post something in the name of my application.

Here is how i'm trying to do this:

protected void btn_submit_Click(object sender, EventArgs e)
{

    Dictionary<string, string> data = new Dictionary<string, string>();
    data.Add("message", "Testing");
    // i'll add more data later here (picture, link, ...)
    data.Add("access_token", FbGraphApi.getAppToken());
    FbGraphApi.postOnWall(ConfigSettings.getFbPageId(), data);

}

FbGraphApi.getAppToken()

// ...
private static string graphUrl = "https://graph.facebook.com";
//...

public static string getAppToken() {
    MyWebRequest req = new MyWebRequest(graphUrl + "/" + "oauth/access_token?type=client_cred&client_id=" + ConfigSettings.getAppID() + "&client_secret=" + ConfigSettings.getAppSecret(), "GET");
    return req.GetResponse().Split('=')[1];
}

FbGraphApi.postOnWall()

public static void postOnWall(string id, Dictionary<string,string> args)
    {
        call(id, "feed", args);
    }

FbGraphApi.call()

private static void call(string id, string method, Dictionary<string,string> args )
{
    string data = "";
    foreach (KeyValuePair<string, string> arg in args)
    {

        data += arg.Key + "=" + arg.Value + "&";

    }

    MyWebRequest req = new MyWebRequest(graphUrl +"/" + id + "/" + method, "POST", data.Substring(0, data.Length - 1));


    req.GetResponse();  // here i get: "The remote server returned an error: (403) Forbidden."
}

Does anyone see where this i going wrong? I'm really stuck on this.

Thanks!

Answer 1

private class FbWebViewClient extends WebViewClient {

    boolean started=false;

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        Log.d("Facebook-WebView", "Redirect URL: " + url);
        if (url.startsWith(Facebook.REDIRECT_URI)) {
            Bundle values = Util.parseUrl(url);

            String error = values.getString("error");
            if (error == null) {
                error = values.getString("error_type");
            }

            if (error == null) {
                mListener.onComplete(values);
            } else if (error.equals("access_denied")
                    || error.equals("OAuthAccessDeniedException")) {
                mListener.onCancel();
            } else {
                mListener.onFacebookError(new FacebookError(error));
            }

            FbDialog.this.dismiss();
            return true;
        } else if (url.startsWith(Facebook.CANCEL_URI)) {
            mListener.onCancel();
            FbDialog.this.dismiss();
            return true;
        } else if (url.contains(DISPLAY_STRING)) {
            return false;
        }
        // launch non-dialog URLs in a full browser
        getContext().startActivity(
                new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
        return true;
    }

    @Override
    public void onReceivedError(WebView view, int errorCode,
            String description, String failingUrl) {
        super.onReceivedError(view, errorCode, description, failingUrl);
        mListener.onError(new DialogError(description, errorCode,
                failingUrl));
        FbDialog.this.dismiss();
    }

    public Map<String, String> getUrlParameters(String url)
            throws UnsupportedEncodingException {
        Map<String, String> params = new HashMap<String, String>();
        String[] urlParts = url.split("\\?");
        if (urlParts.length > 1) {
            String query = urlParts[1];
            for (String param : query.split("&")) {
                String pair[] = param.split("=");
                String key = URLDecoder.decode(pair[0], "UTF-8");
                String value = "";
                if (pair.length > 1) {
                    value = URLDecoder.decode(pair[1], "UTF-8");
                }

                params.put(key, value);

            }
        }
        return params;
    }

    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        Log.d("Facebook-WebView", "Webview loading URL: " + url);

        String newUrl="http://www.facebook.com/dialog/feed?_path=feed&app_id="; 
        if (url.contains("touch") && started==false) {

            started=true;
            ChildTabBibleLessonActivity.fbMaterial=ChildTabBibleLessonActivity.fbMaterial.replace(" ", "+");
            url=url+"&picture=http://www.minibiblecollege.org/mbclandingpage/images/icmlogo-small.jpg&description="+ChildTabBibleLessonActivity.fbMaterial;
        /*  Map<String,String> param;
            try {
                param = getUrlParameters(url);
                newUrl=newUrl+param.get("app_id")+"&redirect_uri="+"https://deep-rain-6015.herokuapp.com"+"&display=page&picture=http://www.minibiblecollege.org/mbclandingpage/images/icmlogo-small.jpg"+"&name=MiniBible&description=heregoesMyMessage";

            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            */
            view.loadUrl(url);
            //super.onPageStarted(view, url, favicon);
        }
        else
        {
        super.onPageStarted(view, url, favicon);
        }
        mSpinner.show();
    }

    @Override
    public void onPageFinished(WebView view, String url) {
        super.onPageFinished(view, url);
        mSpinner.dismiss();
        /*
         * Once webview is fully loaded, set the mContent background to be
         * transparent and make visible the 'x' image.
         */
        mContent.setBackgroundColor(Color.TRANSPARENT);
        mWebView.setVisibility(View.VISIBLE);
        mCrossImage.setVisibility(View.VISIBLE);
    }
}

Answer 2

Recently I had worked With FB api's.
I had Done every thing in javascript.
Here is what i used to post to a users wall.
I hope this helps you.

Include the javascript library provided by FB and add your app id to it.

<div id="fb-root"></div>
      <script>

      window.fbAsyncInit = function() {
        FB.init({appId: 'your app id', status: true, cookie: true,
                 xfbml: true});
      };
      (function() {
        var e = document.createElement('script');
        e.type = 'text/javascript';
        e.src = document.location.protocol +
          '//connect.facebook.net/en_US/all.js';
        e.async = true;
        document.getElementById('fb-root').appendChild(e);
      }());

       </script>

For login , i used a button with "fb_login" as id and then i used jquery as follows:

$("#fb_login").click(function(){
    FB.login(function(response) {
        if (response.session) 
        {
            if (response.perms)
            {
                               // alert("Logged in and permission granted for posting");
            } 
            else 
            {
                  // alert("Logged in but permission not granted for posting"); 
            }
        }
        else
        {
                        //alert("Not Logged In");
        }
}, {perms:'publish_stream'});

Note that You have to add {perms:'publish_stream'} as done above which will obtain you the rights to post to the users wall.

A button with id="stream_publish" and then the following jquery:

$("#stream_publish").click(function(){

      FB.getLoginStatus(function(response){

          if(response.session)
          {
                publishPost(response.session);
          }

      });
});

function publishPost(session)
{
    var publish = {
      method: 'stream.publish',
      message: 'Your Message',
      picture : 'Image to be displayed',
      link : 'The link that will be the part of the post, which can point to either your app page or your personal page or any other page',
      name: 'Name or title of the post',
      caption: 'Caption of the Post',
      description: 'It is fun to write Facebook App!',
      actions : { name : 'Start Learning', link : 'link to the app'}
    };

    FB.api('/me/feed', 'POST', publish, function(response) {  

        document.getElementById('confirmMsg').innerHTML = 
               'A post had just been published into the stream on your wall.';
    });
};

Answer 3

You need to obtain the Auth Token for your application to post as that application.

The Auth_Token defines the security context you are posting as.

You would need to request the following Graph API URL, for the current user, to find the access token for your application.

https://graph.facebook.com/me/accounts?access_token=XXXXXXXX

This should give you an output similar to the following:

{
   "data": [
      {
         "name": "My App",
         "category": "Application",
         "id": "10258853",
     "access_token": "xxxxxxxxxxxxxxxx"
      }
   ]
}

Be sure you have the manage_pages permission before calling that API or your will not get the access token back.

Once you have the Access Token you publish to the wall like you would any other user. Note that the ID used in the URL matches the ID of the application. This will post to the Application's wall as the Application.

https://graph.facebook.com/10258853/feed?access_token=XXXXXXX

Be sure you have the publish_stream permission as well before posting to the wall.