/**
* Generate clustered GEOJSON from incidents
*
* @param ORM_Iterator|Database_Result|array $incidents collection of incidents
* @param int $category_id
* @param string $color
* @param string $icon
* @return array $json_features geojson features array
**/
protected function clusters_geojson($incidents, $category_id, $color, $icon)
{
$json_features = array();
// Extra params for clustering
// Start date
$start_date = (isset($_GET['s']) and intval($_GET['s']) > 0) ? intval($_GET['s']) : NULL;
// End date
$end_date = (isset($_GET['e']) and intval($_GET['e']) > 0) ? intval($_GET['e']) : NULL;
// Get Zoom Level
$zoomLevel = (isset($_GET['z']) and !empty($_GET['z'])) ? (int) $_GET['z'] : 8;
$distance = (10000000 >> $zoomLevel) / 100000;
// Get markers array
if ($incidents instanceof ORM_Iterator) {
$markers = $incidents->as_array();
} elseif ($incidents instanceof Database_Result) {
$markers = $incidents->result_array();
} else {
$markers = $incidents;
}
$clusters = array();
// Clustered
$singles = array();
// Non Clustered
// Loop until all markers have been compared
while (count($markers)) {
$marker = array_pop($markers);
$cluster = array();
// Handle both reports::fetch_incidents() response and actual ORM objects
$marker->id = isset($marker->incident_id) ? $marker->incident_id : $marker->id;
if (isset($marker->latitude) and isset($marker->longitude)) {
$marker_latitude = $marker->latitude;
$marker_longitude = $marker->longitude;
} elseif (isset($marker->location) and isset($marker->location->latitude) and isset($marker->location->longitude)) {
$marker_latitude = $marker->location->latitude;
$marker_longitude = $marker->location->longitude;
} else {
// No location - skip this report
continue;
}
// Compare marker against all remaining markers.
foreach ($markers as $key => $target) {
// Handle both reports::fetch_incidents() response and actual ORM objects
if (isset($target->latitude) and isset($target->longitude)) {
$target_latitude = $target->latitude;
$target_longitude = $target->longitude;
} elseif (isset($target->location) and isset($target->location->latitude) and isset($target->location->longitude)) {
$target_latitude = $target->location->latitude;
$target_longitude = $target->location->longitude;
} else {
// No location - skip this report
continue;
}
// This function returns the distance between two markers, at a defined zoom level.
// $pixels = $this->_pixelDistance($marker['latitude'], $marker['longitude'],
// $target['latitude'], $target['longitude'], $zoomLevel);
$pixels = abs($marker_longitude - $target_longitude) + abs($marker_latitude - $target_latitude);
// If two markers are closer than defined distance, remove compareMarker from array and add to cluster.
if ($pixels < $distance) {
unset($markers[$key]);
$cluster[] = $target;
}
}
// If a marker was added to cluster, also add the marker we were comparing to.
if (count($cluster) > 0) {
$cluster[] = $marker;
$clusters[] = $cluster;
} else {
$singles[] = $marker;
}
}
// Create Json
foreach ($clusters as $cluster) {
// Calculate cluster center
$bounds = $this->calculate_center($cluster);
$cluster_center = array_values($bounds['center']);
$southwest = $bounds['sw']['longitude'] . ',' . $bounds['sw']['latitude'];
$northeast = $bounds['ne']['longitude'] . ',' . $bounds['ne']['latitude'];
// Number of Items in Cluster
$cluster_count = count($cluster);
// Get the time filter
$time_filter = (!empty($start_date) and !empty($end_date)) ? "&s=" . $start_date . "&e=" . $end_date : "";
// Build query string for title link, passing through any GET params
// This allows plugins to extend more easily
$query = http_build_query(array_merge(array('sw' => $southwest, 'ne' => $northeast), $_GET));
// Build out the JSON string
$link = url::site("reports/index/?{$query}");
$item_name = $this->get_title(Kohana::lang('ui_main.reports_count', $cluster_count), $link);
$json_item = array();
$json_item['type'] = 'Feature';
$json_item['properties'] = array('name' => $item_name, 'link' => $link, 'category' => array($category_id), 'color' => $color, 'icon' => $icon, 'thumb' => '', 'timestamp' => 0, 'count' => $cluster_count);
$json_item['geometry'] = array('type' => 'Point', 'coordinates' => $cluster_center);
array_push($json_features, $json_item);
}
// Pass single points to standard markers json
$json_features = array_merge($json_features, $this->markers_geojson($singles, $category_id, $color, $icon, FALSE));
//
// E.Kala July 27, 2011
// @todo Parking this geometry business for review
//
/*
//Get Incident Geometries
$geometry = $this->_get_geometry($marker->incident_id, $marker->incident_title, $marker->incident_date);
if (count($geometry))
{
foreach ($geometry as $g)
{
array_push($json_features, $g);
}
}
*/
Event::run('ushahidi_filter.json_cluster_features', $json_features);
return $json_features;
}