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Drupal example source code file (install.inc)

This example Drupal source code file (install.inc) is included in the DevDaily.com "Drupal Source Code Warehouse" project. The intent of this project is to help you "Learn Drupal by Example".

PHP - Drupal tags/keywords

array, database, directory, file, foreach, function, if, install, module, module_list, php, return, schema, variable

The install.inc Drupal example source code

<?php
// $Id: install.inc,v 1.56.2.4 2009/02/16 10:25:02 goba Exp $

define('SCHEMA_UNINSTALLED', -1);
define('SCHEMA_INSTALLED', 0);

define('REQUIREMENT_INFO', -1);
define('REQUIREMENT_OK', 0);
define('REQUIREMENT_WARNING', 1);
define('REQUIREMENT_ERROR', 2);

define('FILE_EXIST',          1);
define('FILE_READABLE',       2);
define('FILE_WRITABLE',       4);
define('FILE_EXECUTABLE',     8);
define('FILE_NOT_EXIST',      16);
define('FILE_NOT_READABLE',   32);
define('FILE_NOT_WRITABLE',   64);
define('FILE_NOT_EXECUTABLE', 128);

/**
 * Initialize the update system by loading all installed module's .install files.
 */
function drupal_load_updates() {
  foreach (drupal_get_installed_schema_version(NULL, FALSE, TRUE) as $module => $schema_version) {
    if ($schema_version > -1) {
      module_load_install($module);
    }
  }
}

/**
 * Returns an array of available schema versions for a module.
 *
 * @param $module
 *   A module name.
 * @return
 *   If the module has updates, an array of available updates sorted by version. 
 *   Otherwise, FALSE.
 */
function drupal_get_schema_versions($module) {
  $updates = array();
  $functions = get_defined_functions();
  foreach ($functions['user'] as $function) {
    if (strpos($function, $module .'_update_') === 0) {
      $version = substr($function, strlen($module .'_update_'));
      if (is_numeric($version)) {
        $updates[] = $version;
      }
    }
  }
  if (count($updates) == 0) {
    return FALSE;
  }
  sort($updates, SORT_NUMERIC);
  return $updates;
}

/**
 * Returns the currently installed schema version for a module.
 *
 * @param $module
 *   A module name.
 * @param $reset
 *   Set to TRUE after modifying the system table.
 * @param $array
 *   Set to TRUE if you want to get information about all modules in the
 *   system.
 * @return
 *   The currently installed schema version.
 */
function drupal_get_installed_schema_version($module, $reset = FALSE, $array = FALSE) {
  static $versions = array();

  if ($reset) {
    $versions = array();
  }

  if (!$versions) {
    $versions = array();
    $result = db_query("SELECT name, schema_version FROM {system} WHERE type = '%s'", 'module');
    while ($row = db_fetch_object($result)) {
      $versions[$row->name] = $row->schema_version;
    }
  }

  return $array ? $versions : $versions[$module];
}

/**
 * Update the installed version information for a module.
 *
 * @param $module
 *   A module name.
 * @param $version
 *   The new schema version.
 */
function drupal_set_installed_schema_version($module, $version) {
  db_query("UPDATE {system} SET schema_version = %d WHERE name = '%s'", $version, $module);
}

/**
 * Loads the profile definition, extracting the profile's defined name.
 *
 * @return
 *   The name defined in the profile's _profile_details() hook.
 */
function drupal_install_profile_name() {
  global $profile;
  static $name = NULL;

  if (!isset($name)) {
    // Load profile details.
    $function = $profile .'_profile_details';
    if (function_exists($function)) {
      $details = $function();
    }
    $name = isset($details['name']) ? $details['name'] : 'Drupal';
  }

  return $name;
}

/**
 * Auto detect the base_url with PHP predefined variables.
 *
 * @param $file
 *   The name of the file calling this function so we can strip it out of
 *   the URI when generating the base_url.
 *
 * @return
 *   The auto-detected $base_url that should be configured in settings.php
 */
function drupal_detect_baseurl($file = 'install.php') {
  global $profile;
  $proto = $_SERVER['HTTPS'] ? 'https://' : 'http://';
  $host = $_SERVER['SERVER_NAME'];
  $port = ($_SERVER['SERVER_PORT'] == 80 ? '' : ':'. $_SERVER['SERVER_PORT']);
  $uri = preg_replace("/\?.*/", '', $_SERVER['REQUEST_URI']);
  $dir = str_replace("/$file", '', $uri);

  return "$proto$host$port$dir";
}

/**
 * Detect all databases supported by Drupal that are compiled into the current
 * PHP installation.
 *
 * @return
 *  An array of database types compiled into PHP.
 */
function drupal_detect_database_types() {
  $databases = array();

  foreach (array('mysql', 'mysqli', 'pgsql') as $type) {
    if (file_exists('./includes/install.'. $type .'.inc')) {
      include_once './includes/install.'. $type .'.inc';
      $function = $type .'_is_available';
      if ($function()) {
        $databases[$type] = $type;
      }
    }
  }

  return $databases;
}

/**
 * Read settings.php into a buffer line by line, changing values specified in
 * $settings array, then over-writing the old settings.php file.
 *
 * @param $settings
 *   An array of settings that need to be updated.
 */
function drupal_rewrite_settings($settings = array(), $prefix = '') {
  $default_settings = './sites/default/default.settings.php';
  $settings_file = './'. conf_path(FALSE, TRUE) .'/'. $prefix .'settings.php';

  // Build list of setting names and insert the values into the global namespace.
  $keys = array();
  foreach ($settings as $setting => $data) {
    $GLOBALS[$setting] = $data['value'];
    $keys[] = $setting;
  }

  $buffer = NULL;
  $first = TRUE;
  if ($fp = fopen($default_settings, 'r')) {
    // Step line by line through settings.php.
    while (!feof($fp)) {
      $line = fgets($fp);
      if ($first && substr($line, 0, 5) != '<?php') {
        $buffer = "<?php\n\n";
      }
      $first = FALSE;
      // Check for constants.
      if (substr($line, 0, 7) == 'define(') {
        preg_match('/define\(\s*[\'"]([A-Z_-]+)[\'"]\s*,(.*?)\);/', $line, $variable);
        if (in_array($variable[1], $keys)) {
          $setting = $settings[$variable[1]];
          $buffer .= str_replace($variable[2], " '". $setting['value'] ."'", $line);
          unset($settings[$variable[1]]);
          unset($settings[$variable[2]]);
        }
        else {
          $buffer .= $line;
        }
      }
      // Check for variables.
      elseif (substr($line, 0, 1) == '$') {
        preg_match('/\$([^ ]*) /', $line, $variable);
        if (in_array($variable[1], $keys)) {
          // Write new value to settings.php in the following format:
          //    $'setting' = 'value'; // 'comment'
          $setting = $settings[$variable[1]];
          $buffer .= '$'. $variable[1] ." = '". $setting['value'] ."';". (!empty($setting['comment']) ? ' // '. $setting['comment'] ."\n" : "\n");
          unset($settings[$variable[1]]);
        }
        else {
          $buffer .= $line;
        }
      }
      else {
        $buffer .= $line;
      }
    }
    fclose($fp);

    // Add required settings that were missing from settings.php.
    foreach ($settings as $setting => $data) {
      if ($data['required']) {
        $buffer .= "\$$setting = '". $data['value'] ."';\n";
      }
    }

    $fp = fopen($settings_file, 'w');
    if ($fp && fwrite($fp, $buffer) === FALSE) {
      drupal_set_message(st('Failed to modify %settings, please verify the file permissions.', array('%settings' => $settings_file)), 'error');
    }
  }
  else {
    drupal_set_message(st('Failed to open %settings, please verify the file permissions.', array('%settings' => $default_settings)), 'error');
  }
}

/**
 * Get list of all .install files.
 *
 * @param $module_list
 *   An array of modules to search for their .install files.
 */
function drupal_get_install_files($module_list = array()) {
  $installs = array();
  foreach ($module_list as $module) {
    $installs = array_merge($installs, drupal_system_listing($module .'.install$', 'modules'));
  }
  return $installs;
}

/**
 * Verify a profile for installation.
 *
 * @param profile
 *   Name of profile to verify.
 * @param locale
 *   Name of locale used (if any).
 * @return
 *   The list of modules to install.
 */
function drupal_verify_profile($profile, $locale) {
  include_once './includes/file.inc';
  include_once './includes/common.inc';

  $profile_file = "./profiles/$profile/$profile.profile";

  if (!isset($profile) || !file_exists($profile_file)) {
    install_no_profile_error();
  }

  require_once($profile_file);

  // Get a list of modules required by this profile.
  $function = $profile .'_profile_modules';
  $module_list = array_merge(drupal_required_modules(), $function(), ($locale != 'en' && !empty($locale) ? array('locale') : array()));

  // Get a list of modules that exist in Drupal's assorted subdirectories.
  $present_modules = array();
  foreach (drupal_system_listing('\.module$', 'modules', 'name', 0) as $present_module) {
    $present_modules[] = $present_module->name;
  }

  // Verify that all of the profile's required modules are present.
  $missing_modules = array_diff($module_list, $present_modules);
  if (count($missing_modules)) {
    foreach ($missing_modules as $module) {
      drupal_set_message(st('The %module module is required but was not found. Please move it into the <em>modules</em> subdirectory.', array('%module' => $module)), 'error');
    }
  }
  else {
    return $module_list;
  }
}

/**
 * Calls the install function and updates the system table for a given list of
 * modules.
 *
 * @param module_list
 *   The modules to install.
 */
function drupal_install_modules($module_list = array()) {
  $files = module_rebuild_cache();
  $module_list = array_flip(array_values($module_list));
  do {
    $moved = FALSE;
    foreach ($module_list as $module => $weight) {
      $file = $files[$module];
      if (isset($file->info['dependencies']) && is_array($file->info['dependencies'])) {
        foreach ($file->info['dependencies'] as $dependency) {
          if (isset($module_list[$dependency]) && $module_list[$module] < $module_list[$dependency] +1) {
            $module_list[$module] = $module_list[$dependency] +1;
            $moved = TRUE;
          }
        }
      }
    }
  } while ($moved);
  asort($module_list);
  $module_list = array_keys($module_list);
  array_filter($module_list, '_drupal_install_module');
  module_enable($module_list);
}

/**
 * Callback to install an individual profile module.
 *
 * Used during installation to install modules one at a time and then
 * enable them, or to install a number of modules at one time
 * from admin/build/modules.
 */
function _drupal_install_module($module) {
  if (drupal_get_installed_schema_version($module, TRUE) == SCHEMA_UNINSTALLED) {
    module_load_install($module);
    module_invoke($module, 'install');
    $versions = drupal_get_schema_versions($module);
    drupal_set_installed_schema_version($module, $versions ? max($versions) : SCHEMA_INSTALLED);
    return TRUE;
  }
}

/**
 * Callback to install the system module.
 *
 * Separated from the installation of other modules so core system
 * functions can be made available while other modules are installed.
 */
function drupal_install_system() {
  $system_path = dirname(drupal_get_filename('module', 'system', NULL));
  require_once './'. $system_path .'/system.install';
  module_invoke('system', 'install');
  $system_versions = drupal_get_schema_versions('system');
  $system_version = $system_versions ? max($system_versions) : SCHEMA_INSTALLED;
  db_query("INSERT INTO {system} (filename, name, type, owner, status, throttle, bootstrap, schema_version) VALUES('%s', '%s', '%s', '%s', %d, %d, %d, %d)", $system_path .'/system.module', 'system', 'module', '', 1, 0, 0, $system_version);
  // Now that we've installed things properly, bootstrap the full Drupal environment
  drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
  module_rebuild_cache();
}


/**
 * Calls the uninstall function and updates the system table for a given module.
 *
 * @param $module
 *   The module to uninstall.
 */
function drupal_uninstall_module($module) {
  // First, retrieve all the module's menu paths from db.
  drupal_load('module', $module);
  $paths = module_invoke($module, 'menu');

  // Uninstall the module(s).
  module_load_install($module);
  module_invoke($module, 'uninstall');

  // Now remove the menu links for all paths declared by this module.
  if (!empty($paths)) {
    $paths = array_keys($paths);
    // Clean out the names of load functions.
    foreach ($paths as $index => $path) {
      $parts = explode('/', $path, MENU_MAX_PARTS);
      foreach ($parts as $k => $part) {
        if (preg_match('/^%[a-z_]*$/', $part)) {
          $parts[$k] = '%';
        }
      }
      $paths[$index] = implode('/', $parts);
    }
    $placeholders = implode(', ', array_fill(0, count($paths), "'%s'"));

    $result = db_query('SELECT * FROM {menu_links} WHERE router_path IN ('. $placeholders .') AND external = 0 ORDER BY depth DESC', $paths);
    // Remove all such items. Starting from those with the greatest depth will
    // minimize the amount of re-parenting done by menu_link_delete().
    while ($item = db_fetch_array($result)) {
      _menu_delete_item($item, TRUE);
    }
  }

  drupal_set_installed_schema_version($module, SCHEMA_UNINSTALLED);
}

/**
 * Verify the state of the specified file.
 *
 * @param $file
 *   The file to check for.
 * @param $mask
 *   An optional bitmask created from various FILE_* constants.
 * @param $type
 *   The type of file. Can be file (default), dir, or link.
 * @return
 *   TRUE on success or FALSE on failure. A message is set for the latter.
 */
function drupal_verify_install_file($file, $mask = NULL, $type = 'file') {
  $return = TRUE;
  // Check for files that shouldn't be there.
  if (isset($mask) && ($mask & FILE_NOT_EXIST) && file_exists($file)) {
    return FALSE;
  }
  // Verify that the file is the type of file it is supposed to be.
  if (isset($type) && file_exists($file)) {
    $check = 'is_'. $type;
    if (!function_exists($check) || !$check($file)) {
      $return = FALSE;
    }
  }

  // Verify file permissions.
  if (isset($mask)) {
    $masks = array(FILE_EXIST, FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);
    foreach ($masks as $current_mask) {
      if ($mask & $current_mask) {
        switch ($current_mask) {
          case FILE_EXIST:
            if (!file_exists($file)) {
              if ($type == 'dir') {
                drupal_install_mkdir($file, $mask);
              }
              if (!file_exists($file)) {
                $return = FALSE;
              }
            }
            break;
          case FILE_READABLE:
            if (!is_readable($file) && !drupal_install_fix_file($file, $mask)) {
              $return = FALSE;
            }
            break;
          case FILE_WRITABLE:
            if (!is_writable($file) && !drupal_install_fix_file($file, $mask)) {
              $return = FALSE;
            }
            break;
          case FILE_EXECUTABLE:
            if (!is_executable($file) && !drupal_install_fix_file($file, $mask)) {
              $return = FALSE;
            }
            break;
          case FILE_NOT_READABLE:
            if (is_readable($file) && !drupal_install_fix_file($file, $mask)) {
              $return = FALSE;
            }
            break;
          case FILE_NOT_WRITABLE:
            if (is_writable($file) && !drupal_install_fix_file($file, $mask)) {
              $return = FALSE;
            }
            break;
          case FILE_NOT_EXECUTABLE:
            if (is_executable($file) && !drupal_install_fix_file($file, $mask)) {
              $return = FALSE;
            }
            break;
        }
      }
    }
  }
  return $return;
}

/**
 * Create a directory with specified permissions.
 *
 * @param file
 *  The name of the directory to create;
 * @param mask
 *  The permissions of the directory to create.
 * @param $message
 *  (optional) Whether to output messages. Defaults to TRUE.
 *
 * @return
 *  TRUE/FALSE whether or not the directory was successfully created.
 */
function drupal_install_mkdir($file, $mask, $message = TRUE) {
  $mod = 0;
  $masks = array(FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);
  foreach ($masks as $m) {
    if ($mask & $m) {
      switch ($m) {
        case FILE_READABLE:
          $mod += 444;
          break;
        case FILE_WRITABLE:
          $mod += 222;
          break;
        case FILE_EXECUTABLE:
          $mod += 111;
          break;
      }
    }
  }

  if (@mkdir($file, intval("0$mod", 8))) {
    return TRUE;
  }
  else {
    return FALSE;
  }
}

/**
 * Attempt to fix file permissions.
 *
 * The general approach here is that, because we do not know the security
 * setup of the webserver, we apply our permission changes to all three
 * digits of the file permission (i.e. user, group and all).
 *
 * To ensure that the values behave as expected (and numbers don't carry
 * from one digit to the next) we do the calculation on the octal value
 * using bitwise operations. This lets us remove, for example, 0222 from
 * 0700 and get the correct value of 0500.
 *
 * @param $file
 *  The name of the file with permissions to fix.
 * @param $mask
 *  The desired permissions for the file.
 * @param $message
 *  (optional) Whether to output messages. Defaults to TRUE.
 *
 * @return
 *  TRUE/FALSE whether or not we were able to fix the file's permissions.
 */
function drupal_install_fix_file($file, $mask, $message = TRUE) {
  $mod = fileperms($file) & 0777;
  $masks = array(FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);

  // FILE_READABLE, FILE_WRITABLE, and FILE_EXECUTABLE permission strings
  // can theoretically be 0400, 0200, and 0100 respectively, but to be safe
  // we set all three access types in case the administrator intends to
  // change the owner of settings.php after installation.
  foreach ($masks as $m) {
    if ($mask & $m) {
      switch ($m) {
        case FILE_READABLE:
          if (!is_readable($file)) {
            $mod |= 0444;
          }
          break;
        case FILE_WRITABLE:
          if (!is_writable($file)) {
            $mod |= 0222;
          }
          break;
        case FILE_EXECUTABLE:
          if (!is_executable($file)) {
            $mod |= 0111;
          }
          break;
        case FILE_NOT_READABLE:
          if (is_readable($file)) {
            $mod &= ~0444;
          }
          break;
        case FILE_NOT_WRITABLE:
          if (is_writable($file)) {
            $mod &= ~0222;
          }
          break;
        case FILE_NOT_EXECUTABLE:
          if (is_executable($file)) {
            $mod &= ~0111;
          }
          break;
      }
    }
  }

  // chmod() will work if the web server is running as owner of the file.
  // If PHP safe_mode is enabled the currently executing script must also
  // have the same owner.
  if (@chmod($file, $mod)) {
    return TRUE;
  }
  else {
    return FALSE;
  }
}


/**
 * Send the user to a different installer page. This issues an on-site HTTP
 * redirect. Messages (and errors) are erased.
 *
 * @param $path
 *   An installer path.
 */
function install_goto($path) {
  global $base_url;
  header('Location: '. $base_url .'/'. $path);
  header('Cache-Control: no-cache'); // Not a permanent redirect.
  exit();
}

/**
 * Hardcoded function for doing the equivalent of t() during
 * the install process, when database, theme, and localization
 * system is possibly not yet available.
 */
function st($string, $args = array()) {
  static $locale_strings = NULL;
  global $profile, $install_locale;

  if (!isset($locale_strings)) {
    $locale_strings = array();
    $filename = './profiles/'. $profile .'/translations/'. $install_locale .'.po';
    if (file_exists($filename)) {
      require_once './includes/locale.inc';
      $file = (object) array('filepath' => $filename);
      _locale_import_read_po('mem-store', $file);
      $locale_strings = _locale_import_one_string('mem-report');
    }
  }

  require_once './includes/theme.inc';
  // Transform arguments before inserting them
  foreach ($args as $key => $value) {
    switch ($key[0]) {
      // Escaped only
      case '@':
        $args[$key] = check_plain($value);
        break;
      // Escaped and placeholder
      case '%':
      default:
        $args[$key] = '<em>'. check_plain($value) .'</em>';
        break;
      // Pass-through
      case '!':
    }
  }
  return strtr((!empty($locale_strings[$string]) ? $locale_strings[$string] : $string), $args);
}

/**
 * Check a profile's requirements.
 *
 * @param profile
 *   Name of profile to check.
 */
function drupal_check_profile($profile) {
  include_once './includes/file.inc';

  $profile_file = "./profiles/$profile/$profile.profile";

  if (!isset($profile) || !file_exists($profile_file)) {
    install_no_profile_error();
  }

  require_once($profile_file);

  // Get a list of modules required by this profile.
  $function = $profile .'_profile_modules';
  $module_list = array_unique(array_merge(drupal_required_modules(), $function()));

  // Get a list of all .install files.
  $installs = drupal_get_install_files($module_list);

  // Collect requirement testing results
  $requirements = array();
  foreach ($installs as $install) {
    require_once $install->filename;
    if (module_hook($install->name, 'requirements')) {
      $requirements = array_merge($requirements, module_invoke($install->name, 'requirements', 'install'));
    }
  }
  return $requirements;
}

/**
 * Extract highest severity from requirements array.
 */
function drupal_requirements_severity(&$requirements) {
  $severity = REQUIREMENT_OK;
  foreach ($requirements as $requirement) {
    if (isset($requirement['severity'])) {
      $severity = max($severity, $requirement['severity']);
    }
  }
  return $severity;
}

/**
 * Check a module's requirements.
 */
function drupal_check_module($module) {
  // Include install file
  $install = drupal_get_install_files(array($module));
  if (isset($install[$module])) {
    require_once $install[$module]->filename;

    // Check requirements
    $requirements = module_invoke($module, 'requirements', 'install');
    if (is_array($requirements) && drupal_requirements_severity($requirements) == REQUIREMENT_ERROR) {
      // Print any error messages
      foreach ($requirements as $requirement) {
        if (isset($requirement['severity']) && $requirement['severity'] == REQUIREMENT_ERROR) {
          $message = $requirement['description'];
          if (isset($requirement['value']) && $requirement['value']) {
            $message .= ' ('. t('Currently using !item !version', array('!item' => $requirement['title'], '!version' => $requirement['value'])) .')';
          }
          drupal_set_message($message, 'error');
        }
      }
      return FALSE;
    }
  }
  return TRUE;
}

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