php function doesn't work at second iteration

Question

I have write a function file that has de following code:

<?php

  function get_lat_long_from_address($address)
  {

    $prepAddr = str_replace(' ','+',$address); 
    $geocode=file_get_contents('http://maps.google.com/maps/api/geocode/json?address='.$prepAddr.'&sensor=false'); 
    $output= json_decode($geocode);

    $lat = $output->results[0]->geometry->location->lat;
    $long = $output->results[0]->geometry->location->lng;

    return array($lat,$long);
  }

  //function get_closest_disco($client_adress)
  //{
    include ('connection.php');

    $num_discos = get_num_discos();
    $client_address = "C/ Sant Pere, 69, Barcelona";
    list($client_lat,$client_long) = get_lat_long_from_address($client_address);
    echo $client_address.'<br>Lat: '.$client_lat.'<br>Long: '.$client_long;
    $query = 'SELECT adress FROM disco';
    $result = mysql_query($query,$connect);

    while ($row = mysql_fetch_row($result))
    {
        $disco_address[] = $row;        
    }

    for ($i = 0; $i<count($disco_address); $i++)
    {
        $all_disco_address[] = implode(',', $disco_address[$i]);        
    }
    echo '<br>';
    var_dump($disco_address);
    echo '<br>';
    print_r($disco_address);

    for ($i = 0; $i<count($disco_address); $i++)
    {
        list($disco_lat,$disco_long) = get_lat_long_from_address($disco_address[$i][0]);
        /*$d = acos(sin($client_lat)*sin($disco_lat) + 
                  cos($client_lat)*cos($disco_lat) *
                  cos($client_long-$disco_long)) * 6371000;*/
        echo $all_disco_address[$i].'<br>Lat: '.$disco_lat.'<br>Long: '.$disco_long;

    }
 // }


?>

I want to calculate the latitude and longitude from the adresses I'have stored in my db. Then I make my query and I store the results on the var $disco_address[]. Finally I the function get_lat_long_from_address($address) to obtain the latitude and the longitude from those addresses. The problem is that I can get the lat&long from the first result of the query, but not for the following ones... This i the output I get:

C/ Sant Pere, 69, Barcelona
Lat: 41.4451768
Long: 2.2451514
array(4) { [0]=> array(1) { [0]=> string(35) "C/ Nou de la Rambla, 113, Barcelona" } [1]=> array(1) { [0]=> string(29) "C/ Almogàvers, 122, Barcelona" } [2]=> array(1) { [0]=> string(22) "C/ A sobre de l'Api, 1" } [3]=> array(1) { [0]=> string(27) "C/ Serra i Moret, 6, Mataró" } } 
Array ( [0] => Array ( [0] => C/ Nou de la Rambla, 113, Barcelona ) [1] => Array ( [0] => C/ Almogàvers, 122, Barcelona ) [2] => Array ( [0] => C/ A sobre de l'Api, 1 ) [3] => Array ( [0] => C/ Serra i Moret, 6, Mataró ) ) C/ Nou de la Rambla, 113, Barcelona
Lat: 41.3743451
Long: 2.1694939
Notice: Undefined offset: 0 in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Undefined offset: 0 in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34
C/ Almogàvers, 122, Barcelona
Lat: 
Long: 
Notice: Undefined offset: 0 in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Undefined offset: 0 in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34
C/ A sobre de l'Api, 1
Lat: 
Long: 
Notice: Undefined offset: 0 in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 33

Notice: Undefined offset: 0 in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34

Notice: Trying to get property of non-object in C:\xampp\htdocs\test\functions.php on line 34
C/ Serra i Moret, 6, Mataró
Lat: 
Long:

Looks like there's an error from the second iteration of the last foor loop with the offset of the function get_lat_long_from_address($address), but I don't know why. I'd appreciate any help. Thank you.

Answer 1

I finally found why. Was a matter of adresses. Looks like json_decode doesn't accept addresses with accents. Some of my addresses in my db had accents like: Mataró, Almogàvers. Oh, and also the abreviation of street in my lenguage (catalan) doesn't work well at all ("C/" means "Carrer" and only work in some cases).

Answer 2

I suppose the line 33 and the error is $lat = $output->results[0].

Try to var_dump($output) jus after $output= json_decode($geocode); to see the data returned from gmaps API

Anyway I'm trying to emulate your code this way:

$s = urlencode('C/ Sant Pere, 69, Barcelona');

$j = file_get_contents('http://maps.google.com/maps/api/geocode/json?address='.$s.'&sensor=false');
$j = json_decode($j);

var_dump($j->results[0]);

and I get the correct json result, so maybe you need to provide more details here

Answer 3

The problem is here

$lat = $output->results[0]->geometry->location->lat;
$long = $output->results[0]->geometry->location->lng;

You have to check the $output->status like this:

if ($output->status == "OK") {
    $lat = $output->results[0]->geometry->location->lat;
    $long = $output->results[0]->geometry->location->lng;
    return array($lat,$long);
} else {
    return array("error", $output->status);
}

And change this to:

list($client_lat,$client_long) = get_lat_long_from_address($client_address);
if ($client_lat == "error") {
    echo "status error: " . $client_long;
    exit;
}