Utility drupal php function to get polygon data from node containing a geofield that stores polygons.

gistfile1.php

<?
/**
 * Utility function to get market areas map data.
 * Pretty much just a typical parse entities data into market areas array
 *
 * @param  array $filters contextual array (entity_type, bundle, field_name)
 * @return array $market_areas output array used for painting market area layer.
 */
function capacitype_mapbox_get_market_areas($filters) {
  $market_areas = array();
  // if any of the expected filters are not provided , exit.
  if ( empty($filters['entity_type']) ||
    empty($filters['bundle']) ||
    empty($filters['field_name']) ||
    ($filters['entity_type'] != 'node')
    ) {
    return array();
  }
  $query = new EntityFieldQueryExtraFields();
  $query->entityCondition('entity_type', $filters['entity_type'])
    ->propertyCondition('type', $filters['bundle'])
    // adds node title.
    ->addTag('ctm_mapbox_specific');
  //->propertyCondition('status', 1);
  $results =  $query->execute();
  if (!isset($results['node'])) {
    return array();
  }
  $display_fields = array($filters['field_name']);
  $fields = field_info_instances($filters['entity_type'], $filters['bundle']);
  if (empty($fields)) {
    return array();
  }
  // pretty expensive operation.. try to find a better way..
  // $nodes = node_load_multiple(array_keys($results['node']));

  // better than node_load_multiple because of less hook_node_load calls.
  // depending on cache situation results might have other fields also included from cache data
  // but this makes sure we have all fields data as specified in display fields.
  foreach ($display_fields as $display_field) {
    if (isset($fields[$display_field]['field_id'])) {
      field_attach_load($filters['entity_type'],
        $results['node'],
        FIELD_LOAD_CURRENT,
        array('field_id' => $fields[$display_field]['field_id'])
      );
    }
  }
  geophp_load();
  foreach ($results['node'] as $nid => $node) {
    $feature = $properties = array();
    if (!isset($node->{$filters['field_name']}[LANGUAGE_NONE][0])) {
      continue;
    }
    $item = $node->{$filters['field_name']}[LANGUAGE_NONE][0];
    $geometry = geoPHP::load($item['geom']);
    if ($geometry->isEmpty()) {
      continue;
    }
    $geojson = $geometry->out('json');
    $properties['nid'] = $nid;
    // include the title coming from previous efq query.
    $properties['title'] = $node->extraFields->title;
    if (isset($node->title)) {
      $properties['name'] = $node->title;
    }
    $data = array('geometry' => $geojson);
    if (!empty($properties)) {
      $data['properties'] = $properties;
    }
    $market_areas[] = $data;
  }
  return $market_areas;
}