Geozip: zip code library for CodeIgniter

[eluser]nelson.wells[/eluser]
Hi all,

I was interested in radial zip searches in CodeIgniter, and couldn't really find anything. I found that someone on this board used Micah Carrick's native PHP library to do the same thing I was looking to do, but I decided to go a step further. Here, I have converted his library into a CI library. I'm open to suggestions, but I'm even more open to BitBucket pull requests

Here is my blog post that has the library and how to use it. I'll post the library in the next post... hope it is useful to someone!

[eluser]nelson.wells[/eluser]
[code]<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**
* Copyright 2010 Nelson Wells
* CI Class based on code by Micah Carrick at the following url:
* http://www.micahcarrick.com/04-19-2005/p...ation.html
*
* Distributed under GPL Version 3. See included gpl.txt for license.
*
* http://www.nelsonwells.net
*/

//constant for convering to kilometers from miles
define('M2KM_FACTOR', 1.609344);

// constants for passing $sort to get_zips_in_range()
define('SORT_BY_DISTANCE_ASC', 1);
define('SORT_BY_DISTANCE_DESC', 2);
define('SORT_BY_ZIP_ASC', 3);
define('SORT_BY_ZIP_DESC', 4);

class Geozip
{
var $units;
var $decimals;
var $last_error;
var $CI;

function __construct()
{
$this->CI = get_instance();

$this->units = "miles";
$this->decimals = 2;
}

function get_zip_details($zip)
{
$this->CI->db->select("lat AS lattitude, lon AS longitude, city, county, state_prefix");
$this->CI->db->select("state_name, area_code, time_zone");
$this->CI->db->where("zip_code", $zip);
$results = $this->CI->db->get("zip_code");

if($results->num_rows() < 1)
{
$this->set_last_error("Zip not found in database");
return false;
}
else
{
return $results->row();
}
}

function get_zips_in_range($zip, $range, $sort=1, $include_base=true)
{
//get base zip details
$details = $this->get_zip_point($zip);

if( ! $details)
{
return false;
}

//find max - min lat / long for radius and zero point and query
//only zips in that range.
$lat_range = $range/69.172;
$lon_range = abs($range/(cos($details->lat) * 69.172));
$min_lat = number_format($details->lat - $lat_range, "4", ".", "");
$max_lat = number_format($details->lat + $lat_range, "4", ".", "");
$min_lon = number_format($details->lon - $lon_range, "4", ".", "");
$max_lon = number_format($details->lon + $lon_range, "4", ".", "");

//build the sql query
$this->CI->db->select("zip_code, lat, lon");

if( ! $include_base)
{
$this->CI->db->where("zip_code <>", $zip);
}

$this->CI->db->where("lat BETWEEN '$min_lat' AND '$max_lat'");
$this->CI->db->where("lon BETWEEN '$min_lon' AND '$max_lon'");

$result = $this->CI->db->get("zip_code");

if($result->num_rows() < 1)
{
$this->set_last_error("SQL error in get_zips_in_range");
return false;
}
else
{
//loop through all 40 some thousand zip codes and determine whether
//or not it's within the specified range.

foreach($result->result() as $row)
{
$distance = $this->calculate_mileage($details->lat,$row->lat,$details->lon,$row->lon);

if($this->units == "kilos")
{
$distance *= M2KM_FACTOR;
}

if($distance <= $range)
{
$zips[$row->zip_code] = $distance;
}
}
}

//sort the zips as selected
switch($sort)
{
case SORT_BY_DISTANCE_ASC:
asort($zips);
break;

case SORT_BY_DISTANCE_DESC:
arsort($zips);
break;

case SORT_BY_ZIP_ASC:
ksort($zips);
break;

case SORT_BY_ZIP_DESC:
krsort($zips);
break;
}

return $zips;

}

[eluser]nelson.wells[/eluser]
[code]/*
* Get the distance between 2 zip codes.
*/
function get_distance($zip1, $zip2)
{
//return 0 miles / kilos if its the same zip
if($zip1 == $zip2)
{
return 0;
}

//get the details from the database and exit if there is an error
$details1 = $this->get_zip_point($zip1);
$details2 = $this->get_zip_point($zip2);

if($details1 === false || $details2 === false)
{
return false;
}

//calculate the distance between the 2 zip codes based on
//the latitude and longitude pulled from the database
$miles = $this->calculate_mileage($details1->lat,
$details2->lat,
$details1->lon,
$details2->lon);


if($this->units == "kilos")
{
return round($miles * M2KM_FACTOR, $this->decimals);
}
else
{
return round($miles, $this->decimals);
}
}

/*
* Set the units to describe distance
* Accepts "miles" or "kilos"
*/
function set_units($units = "miles")
{
if($units != "kilos" || $units != "miles")
{
$this->units = "miles";
}
else
{
$this->units = $units;
}
}

function get_last_error()
{
return $this->last_error();
}

/*
* Pull latitude and longitude from the database
*/
private function get_zip_point($zip)
{
$this->CI->db->select("lat, lon")->where("zip_code", $zip);
$result = $this->CI->db->get("zip_code");

if($result->num_rows() < 1)
{
$this->set_last_error("Zip code not found in db: $zip");
return false;
}
else
{
return $result->row();
}
}

private function calculate_mileage($lat1, $lat2, $lon1, $lon2)
{
//convert lattitude/longitude (degrees) to radians for calculations
$lat1 = deg2rad($lat1);
$lon1 = deg2rad($lon1);
$lat2 = deg2rad($lat2);
$lon2 = deg2rad($lon2);

//find the deltas
$delta_lat = $lat2 - $lat1;
$delta_lon = $lon2 - $lon1;

//find the Great Circle distance
$temp = pow(sin($delta_lat/2.0),2) + cos($lat1) * cos($lat2) * pow(sin($delta_lon/2.0),2);
$distance = 3956 * 2 * atan2(sqrt($temp),sqrt(1-$temp));

return $distance;
}

private function set_last_error($error)
{
$this->last_error = $error;
}
}

[eluser]jpwdesigns[/eluser]
Exactly what I was looking for. Thanks for sharing!

[eluser]nomie7[/eluser]
The distance return is a bird path correct not actual driving distance?

[eluser]jpwdesigns[/eluser]
Correct. It is not driving distance but physical distance.