aboutsummaryrefslogtreecommitdiff
path: root/engine/lib/location.php
diff options
context:
space:
mode:
Diffstat (limited to 'engine/lib/location.php')
-rw-r--r--engine/lib/location.php94
1 files changed, 94 insertions, 0 deletions
diff --git a/engine/lib/location.php b/engine/lib/location.php
new file mode 100644
index 000000000..eec665234
--- /dev/null
+++ b/engine/lib/location.php
@@ -0,0 +1,94 @@
+<?php
+
+ /**
+ * Elgg geo-location tagging library.
+ *
+ * @package Elgg
+ * @subpackage Core
+ * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
+ * @author Curverider Ltd
+ * @copyright Curverider Ltd 2008
+ * @link http://elgg.org/
+ */
+
+ /**
+ * Define an interface for geo-tagging entities.
+ *
+ */
+ interface Locatable
+ {
+ /** Set a location text */
+ public function setLocation($location);
+
+ /**
+ * Set latitude and longitude tags for a given entity.
+ *
+ * @param float $lat
+ * @param float $long
+ */
+ public function setLatLong($lat, $long);
+
+ /**
+ * Get the contents of the ->geo:lat field.
+ *
+ */
+ public function getLatitude();
+
+ /**
+ * Get the contents of the ->geo:lat field.
+ *
+ */
+ public function getLongitude();
+
+ /**
+ * Get the ->location metadata.
+ *
+ */
+ public function getLocation();
+ }
+
+ /**
+ * Encode a location into a latitude and longitude, caching the result.
+ *
+ * Works by triggering the 'geocode' 'location' plugin hook, and requires a geocoding module to be installed
+ * activated in order to work.
+ *
+ * @param String $location The location, e.g. "London", or "24 Foobar Street, Gotham City"
+ */
+ function elgg_geocode_location($location)
+ {
+ global $CONFIG;
+
+ $location = sanitise_string($location);
+
+ // Look for cached version
+ $cached_location = get_data_row("SELECT * from {$CONFIG->dbprefix}geocode_cache WHERE location='$location'");
+
+ // Trigger geocode event
+ $return = false;
+ $return = trigger_plugin_hook('geocode', 'location', array('location' => $location, $return));
+
+ // If returned, cache and return value
+ if (($return) && (is_array($return)))
+ {
+ $lat = (int)$return['lat'];
+ $long = (int)$return['long'];
+
+ // Put into cache at the end of the page since we don't really care that much
+ execute_delayed_write_query("INSERT DELAYED INTO {$CONFIG->dbprefix}geocode_cache (lat, long) VALUES ({$lat}, {$long}) ON DUPLICATE KEY UPDATE lat={$lat} long={$long}");
+ }
+
+ return $return;
+ }
+
+ // Some distances in degrees (approximate)
+ define("MILE", 0.01515);
+ define("KILOMETER", 0.00932);
+
+
+ // TODO: get objects within x miles by entities, metadata and relationship
+
+ // TODO: List
+
+
+?> \ No newline at end of file