source: sipes/modules_contrib/geocode/geocode.module @ 8a8efa8

<?php // $Id: geocode.module,v 1.6 2009/12/21 17:34:43 vauxia Exp $

/**
 * The Geocode API call.
 */
function geocode($handler, $input, $return = 'point', $options = array()) {
  static $handlers = array();

  if (!isset($handlers[$handler])) {
    $info = geocode_handler_info();
    if ($h = $info[$handler]) {
      // Load the geocoder's file.
      $path = (isset($h['file path'])) ? $h['file path'] .'/' : '';
      require_once $path . $h['file'];

      // Instantiate a class for it.
      $handlers[$handler] = New $handler($options);
    }
  }

  if (!$handler = $handlers[$handler]) return FALSE;

  if ($handler->geocode($input, $options)) {
    list ($type, $item) = explode(':', $return);
    return $handler->get_result($type, $item);
  }
}

/**
 * Return a list of all handlers that might geocode something for you.
 */
function geocode_handler_info($field_type = NULL, $return_type = NULL) {
  static $handlers;
  if (!$handlers) {
    module_load_include('inc', 'geocode', 'includes/geocode');
    $handlers = module_invoke_all('geocode_handler_info');
    drupal_alter('geocode_handlers', $handlers);
  }
  $return = $handlers;

  if ($field_type) {
    foreach($return as $i => $handler) {
      if (!in_array($field_type, $handler['field types'])) {
        unset($return[$i]);
      }
    }
  }
/* // TODO parse return types.
  if ($return_type) {
    list($group, $type) = explode(':', $return_type);
    foreach($return as $key => $items) {
      if ($key !=
      if (!in_array($field_type, $handler['field types'])) {
        unset($return[$i]);
      }
    }
  }
*/
  return $return;
}

/**
 * Implementation of our own hook_geocode_handler_info().
 */
function geocode_geocode_handler_info() {
  $handlers = array();

  // A default geocoding handler.
  $handlers['geocode_google'] = array(
    'label' => t('Google API'),
    'callback' => 'geocode_handler_google',
    'module' => 'geocode',
    'file' => 'geocode.inc',
    'file path' => drupal_get_path('module', 'geocode') .'/includes',
    'field types' => array('postal_field', 'postal', 'text'),
    'element types' => array('postal', 'textfield', 'textarea'),
    'return types' => array(
      'geo' => array('point'),
      'postal' => array('postal'),
      'text' => array('country', 'city', 'state', 'zip'),
    ),
  );

  // Based on availablilty, include handlers that leverage installed modules.
  // This is for some out-of-the-box interoperability, but should be supplanted
  // by modules implementing hook_geocode_hander_info() on their own.
  $dir = drupal_get_path('module', 'geocode') . '/includes/modules/';
  foreach (file_scan_directory($dir, '\.inc$') as $file) {
    if (module_exists($module = $file->name)) {
      $func = $module . '_geocode_handler_info';

      // Call hook_geocode_handler_info() if the module doesn't account for it.
      if (!function_exists($func) && !function_exists($func .'_alter')) {
        require $dir . $module .'.inc';
        $handlers = array_merge($handlers, $func());
      }
    }
  }

  return $handlers;
}

/**
 * Implementation of hook_gis_input_info().
 */
function geocode_gis_input_info($gis_type = NULL) {
  $inputs = array();
  foreach (geocode_handler_info() as $handler => $info) {
    // Only deal with handlers that attach to a form element.
    if (!isset($info['element types']) || !isset($info['return types']['geo'])) {
       continue;
    }

    foreach ($info['element types'] as $type) {
      $inputs[$handler .'_'. $type] = array(
        'label' => $info['label'] .': '. $type,
        'gis input' => 'wkt',  // TODO this is for compatibility with GIS tools.  Perhaps there's a way to define what we expect?
        'gis types' => $info['return types']['geo'],
        'gis callback' => 'geocode_convert',
        'handler' => $handler,
        'element' => array(
          '#type' => $type,
        ),
      );
    }
  }
  return $inputs;
}

// TODO this should be deprecated completely.  Currently proof of concept.
function geocode_convert($input, $value, $return_format) {
  $handler = $input['handler'];
  return geocode($handler, $value, $return_format);
}