<?php /** * Elgg geo-location tagging library. * * @package Elgg.Core * @subpackage Location */ /** * Encode a location into a latitude and longitude, caching the result. * * Works by triggering the 'geocode' 'location' plugin * hook, and requires a geocoding plugin to be installed. * * @param string $location The location, e.g. "London", or "24 Foobar Street, Gotham City" * @return string|false */ function elgg_geocode_location($location) { global $CONFIG; if (is_array($location)) { return false; } $location = sanitise_string($location); // Look for cached version $query = "SELECT * from {$CONFIG->dbprefix}geocode_cache WHERE location='$location'"; $cached_location = get_data_row($query); if ($cached_location) { return array('lat' => $cached_location->lat, 'long' => $cached_location->long); } // Trigger geocode event if not cached $return = false; $return = elgg_trigger_plugin_hook('geocode', 'location', array('location' => $location), $return); // If returned, cache and return value if (($return) && (is_array($return))) { $lat = (float)$return['lat']; $long = (float)$return['long']; // Put into cache at the end of the page since we don't really care that much $query = "INSERT DELAYED INTO {$CONFIG->dbprefix}geocode_cache " . " (location, lat, `long`) VALUES ('$location', '{$lat}', '{$long}')" . " ON DUPLICATE KEY UPDATE lat='{$lat}', `long`='{$long}'"; execute_delayed_write_query($query); } return $return; } /** * Return entities within a given geographic area. * * Also accepts all options available to elgg_get_entities(). * * @see elgg_get_entities * * @param array $options Array in format: * * latitude => FLOAT Latitude of the location * * longitude => FLOAT Longitude of the location * * distance => FLOAT/ARR ( * latitude => float, * longitude => float, * ) * The distance in degrees that determines the search box. A * single float will result in a square in degrees. * @warning The Earth is round. * * @see ElggEntity::setLatLong() * * @return array * @since 1.8.0 */ function elgg_get_entities_from_location(array $options = array()) { global $CONFIG; if (!isset($options['latitude']) || !isset($options['longitude']) || !isset($options['distance'])) { return false; } if (!is_array($options['distance'])) { $lat_distance = (float)$options['distance']; $long_distance = (float)$options['distance']; } else { $lat_distance = (float)$options['distance']['latitude']; $long_distance = (float)$options['distance']['longitude']; } $lat = (float)$options['latitude']; $long = (float)$options['longitude']; $lat_min = $lat - $lat_distance; $lat_max = $lat + $lat_distance; $long_min = $long - $long_distance; $long_max = $long + $long_distance; $where = array(); $wheres[] = "lat_name.string='geo:lat'"; $wheres[] = "lat_value.string >= $lat_min"; $wheres[] = "lat_value.string <= $lat_max"; $wheres[] = "lon_name.string='geo:long'"; $wheres[] = "lon_value.string >= $long_min"; $wheres[] = "lon_value.string <= $long_max"; $joins = array(); $joins[] = "JOIN {$CONFIG->dbprefix}metadata lat on e.guid=lat.entity_guid"; $joins[] = "JOIN {$CONFIG->dbprefix}metastrings lat_name on lat.name_id=lat_name.id"; $joins[] = "JOIN {$CONFIG->dbprefix}metastrings lat_value on lat.value_id=lat_value.id"; $joins[] = "JOIN {$CONFIG->dbprefix}metadata lon on e.guid=lon.entity_guid"; $joins[] = "JOIN {$CONFIG->dbprefix}metastrings lon_name on lon.name_id=lon_name.id"; $joins[] = "JOIN {$CONFIG->dbprefix}metastrings lon_value on lon.value_id=lon_value.id"; // merge wheres to pass to get_entities() if (isset($options['wheres']) && !is_array($options['wheres'])) { $options['wheres'] = array($options['wheres']); } elseif (!isset($options['wheres'])) { $options['wheres'] = array(); } $options['wheres'] = array_merge($options['wheres'], $wheres); // merge joins to pass to get_entities() if (isset($options['joins']) && !is_array($options['joins'])) { $options['joins'] = array($options['joins']); } elseif (!isset($options['joins'])) { $options['joins'] = array(); } $options['joins'] = array_merge($options['joins'], $joins); return elgg_get_entities_from_relationship($options); } /** * Returns a viewable list of entities from location * * @param array $options * * @see elgg_list_entities() * @see elgg_get_entities_from_location() * * @return string The viewable list of entities * @since 1.8.0 */ function elgg_list_entities_from_location(array $options = array()) { return elgg_list_entities($options, 'elgg_get_entities_from_location'); } // Some distances in degrees (approximate) // @todo huh? see warning on elgg_get_entities_from_location() define("MILE", 0.01515); define("KILOMETER", 0.00932);