Using PHP and Google Maps API to Work Out Distance Between 2 Post Codes (Uk)

Using PHP and google Maps Api to work out distance between 2 post codes (UK)

Assuming you are looking for the geographic distance, first you need to get the latitude and longitude of your two postcodes with the Google Maps server-side geocoding services as in the following example:

$url = 'http://maps.google.com/maps/geo?q=EC3M,+UK&output=csv&sensor=false';

$data = @file_get_contents($url);

$result = explode(",", $data);

echo $result[0]; // status code
echo $result[1]; // accuracy
echo $result[2]; // latitude
echo $result[3]; // longitude

Then you can calculate the distance between the coordinates of your two postcodes by using a great-circle distance implementation such as the following:

• Snipplr - Calculate distance between two coordinates in PHP

Note that the server-side geocoding service may only be used in conjunction with displaying results on a Google map; geocoding results without displaying them on a map is prohibited by the Google Maps API Terms of Service License Restrictions.

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UPDATE:

If you are looking for the driving distance instead of the geographical distance, note that there is no documented and approved method at the moment to access the Google Maps Directions API via an HTTP request on the server-side.

Nevertheless, an undocumented method that returns a JSON output is the following:

http://maps.google.com/maps/nav?q=from:London%20to:Dover

This will return you the driving directions, along with the total driving distance in JSON format: "meters":122977.

The format of the q parameter should be from:xxx%20to:yyy. Replace xxx and yyy with the start and destination respectively. You can use latitude and a longitude coordinates instead of full addresses:

http://maps.google.com/maps/nav?q=from:51.519894,-0.105667%20to:51.129079,1.306925

Note that not only this is undocumented, but it may also violate the restrictions 10.1 and 10.5 of the Google Maps API Terms and Conditions.

You may also be interesting in checking out the following related articles:

• Stack Overflow: Calculate driving directions using PHP?
• Getting distance using GDirections via URL
• Retrieve driving directions from google maps with server-side HTTP calls and show results with static maps for WAP
• Google Maps and Directions, REST Interface?

PHP Distance between 2 UK postcodes

Here is 1 problem with your code

$url = "http://maps.googleapis.com/maps/api/distancematrix/json?origins=postcode1&destinations=$postcode2&mode=driving&language=en-EN&sensor=false";

needs to be

$url = "http://maps.googleapis.com/maps/api/distancematrix/json?origins=$postcode1&destinations=$postcode2&mode=driving&language=en-EN&sensor=false";

So that the URL is correctly generated

EDIT-------------------------------------------------

Ive just ran this code

$url = "http://maps.googleapis.com/maps/api/distancematrix/json?origins=DN17%202HG&destinations=DN17%202HJ&mode=driving&language=en-EN&sensor=false";

$data   = @file_get_contents($url);
$result = json_decode($data, true);
//print_r($result);  //outputs the array

$distance = array( // converts the units
    "meters" => $result["rows"][0]["elements"][0]["distance"]["value"],
    "kilometers" => $result["rows"][0]["elements"][0]["distance"]["value"] / 1000,
    "yards" => $result["rows"][0]["elements"][0]["distance"]["value"] * 1.0936133,
    "miles" => $result["rows"][0]["elements"][0]["distance"]["value"] * 0.000621371
);

print_r($distance);

and it produced me

Array
(
    [meters] => 420
    [kilometers] => 0.42
    [yards] => 459.317586
    [miles] => 0.26097582
)

which is spot on, The problem most likely exists in the postcodes, check that the URL is correct and urlencode the both the postcodes

ANOTHER EDIT ----------------------------

It might be a bigger problem that I thought...

You need to wrap the end bit of code in a function so that the distance can be calculated in for each user

if (isset($_GET['search'])) {
    $userSearch = $_GET['search']; // search for users by username
    $query      = mysql_query("SELECT username, postcode, user_id FROM users WHERE username LIKE '%$userSearch%'");
    $rowcount   = mysql_num_rows($query);

    if ($userSearch == "") {

    } else {
        if ($rowcount != 0) {
            while ($row = mysql_fetch_assoc($query)) {
                $username = $row['username'];
                $postcode = $row['postcode'];

                $user_id = $row['user_id'];
                $sql     = mysql_query("SELECT postcode FROM users WHERE user_id = $user_id");
                $results = mysql_fetch_assoc($sql);
                echo $results['postcode'];
                $distance = getDistance($user_data['postcode'], $postcode); 
                //im not sure where the $user_data comes from but it was in your original code

                echo '<a href="' . $username . '">' . $username . '</a> ' . $postcode . ' is : ' . number_format($distance["miles"], 2) . " Mile(s) away" . '<br/>'; // returns results
            }
        } else {

            echo "No user found";
        }
    }
}

function getDistance($start, $end) {
    // Google Map API which returns the distance between 2 postcodes
    $postcode1 = preg_replace('/\s+/', '', $start); 
    $postcode2 = preg_replace('/\s+/', '', $end);
    $result    = array();

    $url = "http://maps.googleapis.com/maps/api/distancematrix/json?origins=$postcode1&destinations=$postcode2&mode=driving&language=en-EN&sensor=false";

    $data   = @file_get_contents($url);
    $result = json_decode($data, true);
    //print_r($result);  //outputs the array

    return array( // converts the units
        "meters" => $result["rows"][0]["elements"][0]["distance"]["value"],
        "kilometers" => $result["rows"][0]["elements"][0]["distance"]["value"] / 1000,
        "yards" => $result["rows"][0]["elements"][0]["distance"]["value"] * 1.0936133,
        "miles" => $result["rows"][0]["elements"][0]["distance"]["value"] * 0.000621371
    );
}

I really must point out that using mysql_* is not such a good thing, I would recommend looking into mysqli or PDO both which have much safer interface. If you must use the queries in this way make sure you escape the data or you could become a victim of SQL injection!

Using PHP and google Maps Api to work out distance between 2 latitude and longitude

Calculate distance between two points in google maps V3

I think you might be after something like this which has a few good answers.

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