Get nearby locations using google places api in php/codeigniter - codeigniter

Question

I have to fetch results of nearby locations within 2 km of my given latitude/longitude values. Have to do it using Google Places API. Details go here:
http://code.google.com/apis/maps/documentation/javascript/places.html
They have provided a sample code in javascript. But I need to have this in php. Can anyone give me any idea how may I achieve it? Or how may I use this same javascript code in my php controller class? [I am using code igniter framework]. I have been stuck on this issue for so many hours. It will be great if someone can provide a sample php code. Highly appreciate any assistance.
Here is the code of my controller class:
<?php
class Welcome extends CI_Controller {
public function index()
{
$config = "";
//$this->load->library('googlemaps');
$this->load->library('googlemaps');
$config['center'] = '37.4419, -122.1419';
$config['zoom'] = 'auto';
$config['places'] = TRUE;
$config['placesLocation'] = '37.4419, -122.1419';
$config['placesRadius'] = 200;
$this->googlemaps->initialize($config);
$data['map'] = $this->googlemaps->create_map();
$this->load->view('map_view', $data);
}
}
?>
This is the error I encounter while I try to run the above code:
Fatal error: Using $this when not in object context in /Applications/XAMPP/xamppfiles/htdocs/ciplaces/application/controllers/mapcontroller.php on line 9
I am accessing my code using this url:
http://localhost/ciplaces/index.php/mapcontroller
Thanks

Answer 1

I've got a CodeIgniter library that has integration with the Google Maps and Places API. You can find information and download the library here:
http://biostall.com/codeigniter-google-maps-v3-api-library
A demo of the 'Places' integration can also be found below:
http://biostall.com/demos/google-maps-v3-api-codeigniter-library/places
Give me a shout if you have any questions or require any changes made to the library and I'll be happy to help out where I can.
Cheers

Answer 2

I have done something simular in PHP using the Lumb algorithm.
You should be able to get something from the code below (sits in my model, but you can put in anywhere).
public function search($start_latitude, $start_longitude, $radius, $radius_type, $offset, $limit)
{
$results = array();
$locations = array();
$sql = "SELECT `location_id`, `latitude`, `longitude` FROM `table`";
$query = $this->db->query($sql);
if ($query->num_rows() > 0)
{
foreach ($query->result() as $row)
{
$geo_data = $this->_bearing_distance_calc($start_latitude, $start_longitude, $row->latitude, $row->longitude, $radius_type);
$geo_data['radius_type'] = $radius_type;
if($geo_data['distance'] <= $radius)
{
// radial serach results
$locations[] = $row->location_id;
}
}
// return amount requested
$results['total'] = count($locations);
$results['locations'] = array_slice($locations, $offset, $limit);
return $results;
}
else
{
// no results
return FALSE;
}
}
/**
* Calculate Distance Between two points.
*
* This method is used to calculate the distance between to geographical points. <br />
* Used by the search method.
*
* #access private
*
* #param float $device_latitude
* #param float $device_longitude
* #param float $beach_latitude
* #param float $beach_longitude
* #param integer $radius_type
*
* #return array
*/
private function _bearing_distance_calc($start_latitude, $start_longitude, $building_latitude, $building_longitude, $radius_type)
{
// using Rhumb lines(or loxodrome)
// convert to rads for php trig functions
$start_latitude = deg2rad($start_latitude);
$start_longitude = deg2rad($start_longitude);
$building_latitude = deg2rad($building_latitude);
$building_longitude = deg2rad($building_longitude);
// testing variables
//$start_latitude = deg2rad(39.4422);
//$start_longitude = deg2rad(-122.0307);
//$building_latitude = deg2rad(49.4422);
//$building_longitude = deg2rad(-112.0307);
// calculate delta of lat and long
$delta_latitude = $building_latitude-$start_latitude;
$delta_longitude = $building_longitude-$start_longitude;
// earth radius
if ($radius_type == 'miles') // using miles
{
$earth_radius = 3959;
}
else // using kilometers
{
$earth_radius = 6371;
}
// now lets start mathing !!
// cast types
$dPhi = log(tan($building_latitude/2+M_PI/4)/tan($start_latitude/2+M_PI/4));
if ($dPhi != 0)
{
$q = $delta_latitude/$dPhi;
}
else
{
$q = cos($start_latitude);
}
//$q = (!is_nan($delta_latitude/$dPhi)) ? $delta_latitude/$dPhi : cos($start_latitude); // E-W line gives dPhi=0
// if dLon over 180° take shorter rhumb across 180° meridian:
if (abs($delta_longitude) > M_PI)
{
$delta_longitude = $delta_longitude>0 ? -(2*M_PI-$delta_longitude) : (2*M_PI+$delta_longitude);
}
$geo_data = array();
$geo_data['distance'] = sqrt($delta_latitude*$delta_latitude + $q*$q*$delta_longitude*$delta_longitude) * $earth_radius;
$bearing = rad2deg(atan2($delta_longitude, $dPhi));
if($bearing < 0)
{
$bearing = 360 + $bearing;
}
$geo_data['bearing'] = $bearing;
return $geo_data;
}