hughrawlinsonfacebook.pde

import java.io.File;

// application api key and secret
String fbApiKey = "341862115846576";
String fbApiSecret = "d69f58ca2ba4cfc40ac340f61eac1475";

// a comma separated (no spaces!) list of user ids
String fbUserIDs = "1123363239";

/* other settings */
// 
// Facebook RESTful API
String fbRestServer = "https://api.facebook.com/";
String fbRestNode = "restserver.php";

XML[] usersXml;
int currentUser = 0;


void setup ()
{
  size( 300, 200 );

  // the details / params in here define what will be read, see:
  // http://wiki.developers.facebook.com/index.php/Users.getInfo
  String xmlResponse = fbCallMethod( new String[] {
    "method=facebook.friends.get", 
    "uid=" + fbUserIDs, 
    "fields=uid,first_name,last_name", // see link above for more options
    "format=XML"
  }
  );

  PrintWriter writer = createWriter("xml.txt");
  writer.print(xmlResponse);
  writer.flush();
  writer.close();

  if ( xmlResponse == null )  // an error occured
  {
    exit();
    return;
  }

  XML xml;
  xml = loadXML("xml.txt");
  File f = new File(dataPath("xml.txt"));
  f.delete();
  usersXml = xml.getChildren( "uid" );

  for (int i = 0; i < usersXml.length; i++) {
    String friendData = fbCallMethod( new String[] {
      "method=facebook.users.getInfo", 
      "uid=" + usersXml[i].getContent(), 
      "fields=uid,first_name,last_name,birthday_date", // see link above for more options
      "format=XML"
    });

    PrintWriter writer2 = createWriter(usersXml[i].getContent()+".txt");
    writer2.print(friendData);
    writer2.flush();
    writer2.close();
    
    XML xml2 = loadXML(usersXml[i].getContent()+".txt");
    
    println(xml2.getContent());
    
  }

  fill( 0 );
  textFont( createFont( "sans-serif", 24 ) );
  textAlign( CENTER );
  frameRate( 1 );
}


void draw () 
{
  background( 255 );

  String full_name = usersXml[currentUser].getContent();

  text( full_name, width/2, height/2 );

  currentUser++;
  currentUser %= usersXml.length; // modulo, wrap around
}

/**
 *  Place a Facebook call (GET request) using Processing API ( loadStrings(), join() )
 */
String fbCallMethod ( String[] args )
{
  String[] params = new String[args.length + 3];
  System.arraycopy( args, 0, params, 0, args.length );
  params[params.length-3] = "api_key=" + fbApiKey;
  params[params.length-2] = "call_id=" + System.currentTimeMillis();
  params[params.length-1] = "v=1.0";

  String sig = fbGenerateSIG ( params );
  String paramString = join( params, "&" ) + "&sig=" + sig;

  String[] lines = loadStrings( fbRestServer + fbRestNode + "?" + paramString );

  if ( lines == null )
  {
    println( "OUCH, nothing to read from that URL:\n" + fbRestServer + fbRestNode + "?" + paramString );
    return null;
  }

  String response = join( lines, "\n" );

  return response;
}

/**
 *  Generate a call signature, see:
 *  http://wiki.developers.facebook.com/index.php/How_Facebook_Authenticates_Your_Application
 *  http://wiki.developers.facebook.com/index.php/Authorization_and_Authentication_for_Desktop_Applications
 */
String fbGenerateSIG ( String[] args )
{
  java.util.Arrays.sort( args );
  String argString = join( args, "" );
  argString += fbApiSecret;

  return md5Encode( argString );
}

/**
 * MD5 encode a String using Processing API ( hex() )
 */
String md5Encode ( String data )
{
  java.security.MessageDigest digest = null;
  try {
    digest = java.security.MessageDigest.getInstance("MD5");
  } 
  catch ( java.security.NoSuchAlgorithmException nsae ) {
    nsae.printStackTrace();
  }
  digest.update( data.getBytes() );
  byte[] hash = digest.digest();

  StringBuilder hexed = new StringBuilder();

  for ( int i = 0; i < hash.length; i++ ) 
  {
    hexed.append( hex( hash[i], 2 ) );
  }

  return hexed.toString().toLowerCase();
}