context_prefix.module

<?php
// $Id$

/**
 * hook_menu()
 */
function context_prefix_menu($may_cache) {
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'type' => module_exists('context_ui') ? MENU_LOCAL_TASK : MENU_NORMAL_ITEM,
      'title' => t('Context Prefixes'),
      'description' => t('Displays a list of context definitions.'),
      'path' => 'admin/build/context/prefix',
      'callback' => 'context_prefix_admin',
      'access' => user_access('administer site configuration'),
      'weight' => 10,
    );
  }
  return $items;
}

/**
 * hook_init()
 * Checks for any valid context prefixes in request string and sets the context appropriately
 */
function context_prefix_init() {
  $q = isset($_REQUEST["q"]) ? trim($_REQUEST["q"], "/") : '';
  $prefix = _context_prefix_get_prefix($q);
  $items = context_prefix_items();
  if (isset($items[$prefix]) && $active = $items[$prefix] ) {
    context_set('context_prefix', $active->module, $active->id);
    context_set('context_prefix', 'prefix', $prefix);
    // if $_GET and $_REQUEST are different, the path has been aliased
    // we will continue to the aliased destination
    if ($_GET['q'] != $_REQUEST['q']) {
      return;
    }
    // there is nothing beyond the path prefix -- treat as frontpage
    else if ($q == $prefix) {
      $_GET['q'] = variable_get('site_frontpage', 'node');
    }
    // pass the rest of the path onto Drupal cleanly
    else {
      // for now, we check arg(0) + arg(1) for the prefix
      if (strpos($q, $prefix) !== 0) {
        $q = explode('/', $q);
        if ($q[1] == $prefix) {
          unset($q[1]);
        }
        $q = implode('/', $q);
        // reset _REQUEST as other prefixing modules (i18n) will use it and not $_GET
        $_REQUEST['q'] = $_GET['q'] = $q;
      }
      // trim off context path and reset q
      else {
        $q = trim(substr($q, strlen($prefix)), '/');
        $_REQUEST['q'] = $_GET['q'] = _context_prefix_get_normal_path($q, $prefix);
      }
    }
  }
}

/**
 * Page callback for the context_prefix administration page.
 */
function context_prefix_admin() {
  $items = context_prefix_items();
  if ($items) {
    $rows = array();
    foreach ($items as $item) {
      $rows[] = array($item->module, $item->prefix, $item->id);
    }
    return theme('table', array(t('Module'), t('Prefix'), t('ID')), $rows);
  }
  return "<p>". t('No context prefix definitions found.') ."</p>";
}

/**
 * Provides a simple API for validating, adding, and deleting context defintions.
 */
function context_prefix_api($op = 'insert', $context) {
  switch ($op) {
    case 'validate':
      if (check_plain($context['module']) && preg_match('!^[a-z0-9_-]+$!', $context['prefix'])) {
        $id = db_result(db_query("SELECT id FROM {context_prefix} WHERE prefix = '%s'", $context['prefix']));
        return $id ? false : true;
      }
      else {
        return false;
      }
    case 'insert':
      if (context_prefix_api('validate', $context)) {
        $status = db_query("INSERT INTO {context_prefix} (module, prefix, id) VALUES ('%s', '%s', %d)", $context['module'], $context['prefix'], $context['id']);
        return $status;
      }
      return false;
    case 'delete':
      if ($context['prefix']) {
        $param = 'prefix';
        $where = $context['prefix'];
      }
      else if ($context['id']) {
        $param = 'id';
        $where = $context['id'];
      }
      $check = db_result(db_query("SELECT id FROM {context_prefix} WHERE module = '%s' AND $param = '%s'", $context['module'], $where));
      if ($check) {
        $status = db_query("DELETE FROM {context_prefix} WHERE module = '%s' AND $param = '%s'", $context['module'], $where);
        return $status;
      }
      return false;
  }
  return false;
}

/**
 * Returns an array of available context definitions. If provided an
 * optional module argument, will only provide definitions for the
 * specified module. 
 */
function context_prefix_items($module = NULL) {
  static $items;
  static $by_module;
  if (!$items) {
    $items = $by_module = array();
    $result = db_query("SELECT * FROM {context_prefix} ORDER BY module ASC");
    while ($item = db_fetch_object($result)) {
      $items[$item->prefix] = $item;
      $by_module[$item->module][$item->prefix] = $item;
    }
  }
  if ($module) {
    return isset($by_module[$module]) ?  $by_module[$module] : array();
  }
  else {
    return $items;
  }
}

/**
 * Returns a prefix string from a url if a valid one is found
 */
function _context_prefix_get_prefix($q) {
  $exploded_q = explode('/', $q);
  $prefix = array_shift($exploded_q);
  // skip over i18n prefix if found
  if (module_exists('i18n') && function_exists('locale_supported_languages')) {
    $languages = locale_supported_languages();
    $languages = array_keys($languages['name']); // grab only language prefixes
    // if first prefix is in languages array, throw it out and use 2nd prefix
    if (array_search($path, $languages) !== false) {
      $prefix = array_shift($exploded_q);
    }
  }
  // check that this prefix is valid  
  $valid = context_prefix_items();
  if (isset($valid[$prefix])) {
    return $prefix;
  }
  else {
    return false;
  }
}

/**
 * Taken from i18n
 */
function _context_prefix_get_normal_path($path, $prefix) {
  // If bootstrap, drupal_lookup_path is not defined
  if (!function_exists('drupal_get_headers')) {
    return $path;
  }
  // Check alias without lang
  elseif ($alias = drupal_lookup_path('source', $path)) {
    return $alias;
  }
  else {
    return $path;
  }
}

/**
 * Jose's very smart collision avoidance
 */
if (!function_exists('custom_url_rewrite')) {
  function custom_url_rewrite($type, $path, $original) {
    return context_prefix_url_rewrite($type, $path, $original);
  }
}

/**
 * Rewrites path with current context and removes context if searching for source path
 */
function context_prefix_url_rewrite($type, $path, $original) {
  $working_path = $path; // preserve original path

  if (module_exists('i18n')) {
    if ($type == 'alias' && !i18n_get_lang_prefix($path)) {
      $prefix[] = i18n_get_lang();
    }
    elseif ($type == 'source') {
      if ($path == $original) {
        $working_path = i18n_get_normal_path($working_path);
      }
      else { // Path may have been dealiased but still have language prefix
        $working_path = i18n_get_lang_prefix($working_path, TRUE);
      }
    }
  }

  // by now i18n has added/removed language prefix as needed
  if (!clswitch('get')) {
    $context = context_get('context_prefix', 'prefix');
    if ($type == 'alias' && !_context_prefix_get_prefix($working_path) && $context) {
      $prefix[] = $context;
    }
    else if ($type == 'source') {
      if (_context_prefix_get_prefix($working_path)) {
        $working_path = trim(substr($working_path, strlen($context)), '/');
      }
    }
  }
  
  if ($working_path) {
    $prefix[] = $working_path;
  }

  return $prefix ? implode('/', $prefix) : '';
}

/**
 * Custom l wrapper for links that need to leave all group contexts
 */
function cl($text, $path, $attributes = array(), $query = NULL, $fragment = NULL, $absolute = FALSE, $html = FALSE, $dropcontext = FALSE) {
  clswitch('set', $dropcontext);
  if (!$dropcontext && $path == '<front>') {
    $path = context_prefix_url_rewrite('alias', '', '');
  }
  $l = l($text, $path, $attributes, $query, $fragment, $absolute, $html);
  clswitch('reset');
  return $l;
}

/**
 * Returns whether the current l/url call should use context rewriting or not
 */
function clswitch($op, $absolute = null) {
  static $drop;
  switch ($op) {
    case 'set';
      $drop = $absolute;
      break;
    case 'get':
      return $drop;
      break;
    case 'reset':
      $drop = null;
      break;
  }
}

/**
 * Like theme_links, but handles context warping.
 * theme_links couldn't believe it.
 */
function theme_context_links($links, $attributes = array('class' => 'links')) {
  $output = '';

  if (count($links) > 0) {
    $output = '<ul'. drupal_attributes($attributes) .'>';

    $num_links = count($links);
    $i = 1;

    foreach ($links as $key => $link) {
      $class = '';

      // Automatically add a class to each link and also to each LI
      if (isset($link['attributes']) && isset($link['attributes']['class'])) {
        $link['attributes']['class'] .= ' '. $key;
        $class = $key;
      }
      else {
        $link['attributes']['class'] = $key;
        $class = $key;
      }

      // Add first and last classes to the list of links to help out themers.
      $extra_class = '';
      if ($i == 1) {
        $extra_class .= 'first ';
      }
      if ($i == $num_links) {
        $extra_class .= 'last ';
      }
      $output .= '<li class="'. $extra_class . $class .'">';

      // Is the title HTML?
      $html = isset($link['html']) && $link['html'];

      // Initialize fragment and query variables.
      $link['query'] = isset($link['query']) ? $link['query'] : NULL;
      $link['fragment'] = isset($link['fragment']) ? $link['fragment'] : NULL;

      if (isset($link['href'])) {
        if ($link['warp']) {
          $output .= cl($link['title'], $link['href'], $link['attributes'], $link['query'], $link['fragment'], FALSE, $html, TRUE);
        }
        else {
          $output .= l($link['title'], $link['href'], $link['attributes'], $link['query'], $link['fragment'], FALSE, $html);
        }
      }
      else if ($link['title']) {
        //Some links are actually not links, but we wrap these in <span> for adding title and class attributes
        if (!$html) {
          $link['title'] = check_plain($link['title']);
        }
        $output .= '<span'. drupal_attributes($link['attributes']) .'>'. $link['title'] .'</span>';
      }

      $i++;
      $output .= "</li>\n";
    }

    $output .= '</ul>';
  }

  return $output;
}