fb_settings.inc in Drupal for Facebook 5.2

File

fb_settings.inc

<?php

// The URL will look something like fb_cb/NID/fb_cb_type/TYPE
// In the future, there may be additional parameters, like spoofing a session for anonymous visitors.
define('FB_SETTINGS_APP_NID', 'fb_cb');
define('FB_SETTINGS_PAGE_TYPE', 'fb_cb_type');
define('FB_SETTINGS_SESSION_KEY', 'fb_sess');
if (!is_array($conf)) {
  $conf = array();
}

// This allows us to test whether this file has been included
$conf['fb_settings_check'] = TRUE;

// Ensure unique session for facebook app.
$conf['session_inc'] = dirname(__FILE__) . '/fb_session.inc';
if ($nid = _fb_settings_parse(FB_SETTINGS_APP_NID)) {

  // We're providing a canvas page.
  if (isset($_REQUEST['fb_sig']) && isset($_REQUEST['fb_sig_in_canvas'])) {

    // It's a facebook callback to an FBML page.
    // Force clean URLs.  Looks better on facebook, and helps us know
    // what to expect Note that we set our facebook callback to end in
    // "?q=" so clean URLs will work in a facebook app whether or not
    // they work locally
    $conf['clean_url'] = 1;

    // Force the admin theme to be our facebook theme.
    // TODO: find a way to make this configurable.  I.e. to support iframe apps.
    $conf['admin_theme'] = 'fb_fbml';

    // Filters will behave differently on facebook, so we cannot share the cache_filter table.

    /*** NO LONGER NECESSARY XXX
      if (!is_array($db_prefix))
    	if (isset($db_prefix))
    	  $db_prefix = array('default' => $db_prefix);
    	else
    	  $db_prefix = array();
      if (!isset($db_prefix['cache_filter']))
    	$db_prefix['cache_filter'] = 'fb_';
      ***/

    // Worth considering: use db_prefix to give facebook, or each app,
    // it's own set of users.
  }
}

/**
 * Implementation of conf_url_rewrite
 * 
 * Defines the URL rewrite if not defined already.  If it is defined already,
 * or your using 118n modules, you should define a custom_url_rewrite in
 * settings.php which calls fb_canvas_url_rewrite in addition to any others
 * that need to be called.  The order will be important!
 */
if (!function_exists('custom_url_rewrite')) {
  function custom_url_rewrite($type, $path, $original) {
    return fb_settings_url_rewrite($type, $path, $original);
  }
}

/**
 * Rewrite URLs for facebook canvas pages.
 * 
 * Ideally, this function would live in fb_canvas.module and only be
 * set when serving canvas pages.  However, it gets called before
 * modules are loaded.  So it must live here.
 */
function fb_settings_url_rewrite($type, $path, $original) {

  //dpm(func_get_args(), 'fb_canvas_url_rewrite');

  //print("fb_canvas_url_rewrite($type, $path, $original)");
  $prefixes = array(
    FB_SETTINGS_APP_NID,
    FB_SETTINGS_PAGE_TYPE,
    FB_SETTINGS_SESSION_KEY,
  );
  if ($type == 'source') {

    // See if this is a request for us.
    if (strpos($path, FB_SETTINGS_APP_NID . '/') === 0) {

      // Too soon for arg() function.
      $args = explode('/', $path);
      while (count($args) && in_array($args[0], $prefixes)) {
        $key = array_shift($args);
        $value = array_shift($args);
        fb_settings($key, $value);

        // Store for use later.
      }
      if ($app_nid = fb_settings(FB_SETTINGS_APP_NID)) {
        if (count($args)) {
          $path = implode('/', $args);

          // remaining args
          $path = drupal_get_normal_path($path);
        }
        else {

          // frontpage
          $path = drupal_get_normal_path(variable_get('site_frontpage', 'node'));
        }
      }
    }
  }
  else {
    if ($type == 'alias') {
      $pre = '';

      // Prefix each known value to the URL
      foreach ($prefixes as $prefix) {
        if ($value = fb_settings($prefix)) {
          $pre .= $prefix . '/' . $value . '/';
        }
      }
      $path = $pre . $path;
    }
  }
  return $path;
}
function fb_settings($key, $value = NULL) {
  static $cache = array();
  if (isset($value)) {
    $cache[$key] = $value;
  }
  return $cache[$key];
}

/**
 * Parse a setting from the URL.  This may be called before
 * custom_url_rewrite, so we can't count on fb_settings() to return the value.
 * For internal use only (see fb_session.inc).
 */
function _fb_settings_parse($key) {
  if (isset($_GET['q'])) {
    $path = $_GET['q'];
    $pos = strpos($path, $key . '/');
    if ($pos !== FALSE) {

      // Too soon for arg() function.
      $args = explode('/', $path);
      $i = 0;
      while (isset($args[$i]) && isset($args[$i + 1])) {
        if ($args[$i] == $key) {

          // Found the value we're interested in
          return $args[$i + 1];
        }
        $i = $i + 2;
      }
    }
  }
}

Functions

Name	Description
fb_settings
fb_settings_url_rewrite	Rewrite URLs for facebook canvas pages.
_fb_settings_parse	Parse a setting from the URL. This may be called before custom_url_rewrite, so we can't count on fb_settings() to return the value. For internal use only (see fb_session.inc).

Constants

Name	Description
FB_SETTINGS_APP_NID
FB_SETTINGS_PAGE_TYPE
FB_SETTINGS_SESSION_KEY