How to post images on Facebook wall on a single button click from an iPhone app

I am making an iPhone app where in the user wants that the selected image should be posted on Facebook wall on a single button click. I have Actionsheet button for this.

I want that both authentication of user (loginButtonTapped in tutorial below) and posting images to the wall (rateTapped in tutorial below) be carried out on a single button click.

I am using the example on the link below as my reference for posting images on Facebook wall

http://www.raywenderlich.com/1626/how-to-post-to-a-users-wall-upload-photos-and-add-a-like-button-from-your-iphone-app

I am a beginner. What should I do?

You can use the facebook Graph Api for posting images to wall..

Here is the tutorial for this...

http://www.capturetheconversation.com/technology/iphone-facebook-oauth-2-0-and-the-graph-api-a-tutorial-part-2