help with php and xml for yahoo service

Question

I am working on a PHP code for my social network, what I am planning to do is on user signup or profile update I will take there zipcode that they enter and use yahoo to lookup there lattitude and logitude from there zipcode I will then save these value to there user mysql table, this will be used later on to find users located within X amount of miles from them.

Here is my code so far to get this info before storing into DB

<?PHP
function yahoo_geo($location) {
    $q = 'http://api.local.yahoo.com/MapsService/V1/geocode';
    q .= '?appid=rlerdorf&location='.rawurlencode($location);
    echo $q;
    libxml_use_internal_errors(true);
    $xml = simplexml_load_file($q); 
    if(!is_object($xml)) return false;
    $ret['precision'] = (string)$xml->Result['precision'];
    foreach($xml->Result->children() as $key=>$val) {
     if(strlen($val)){
      $ret[(string)$key] =  (string)$val;
     } 
    return $ret;
}

$_REQUEST['location'] = 32744; // my zip code
$a = yahoo_geo($_REQUEST['location']);

// set retunred data to some variables for storage into MySQL
$latitude = $a[Latitude];
$longitude = $a[Longitude];

    // MySQL code will go here

// Output for demo
echo 'Lattitude' .$latitude. '<BR><BR>';
echo 'Longitude' .$longitude. '<BR><BR>';
?>

This works great except if a long. and lat. is not found it returns an error to the browser

Warning: simplexml_load_file(http://api.local.yahoo.com/MapsService/V1/geocode?appid=rlerdorf&location=some non zipcode) [function.simplexml-load-file]: failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request in C:\webserver\htdocs\test\geolocation\index.php on line 16

Note; I could make sure that zipcode is numeric only but I would rather not as yahoo will let me search with other fields as well, so If a user does not enter a zipcode I will make it use a city or state or even country at the worse case so every user should have some sort of longitude and lat. saved

Is there a good way to avoid the error showing or even better is there a way to detect id there is an error and if an error occurs I could insert a default value for that user?

Answer 1

Not exactly sure what your question is, but I think you're looking for the error control operator @

xml = @simplexml_load_file($q);

Your function will then return false as normal. You need to check that later though (and add some quotes):

if (!$a)
{
    // Do something
}
else
{
    $latitude = $a['Latitude'];
    $longitude = $a['Longitude'];
}

Answer 2

With the @ operator :

• you have to use it everytime you need it
• when you want to debug, you have to remove it from everywhere (or use the scream extension -- which you cannot always install, depending on your hosting service)
• if there is an error somewhere you didn't put @, it will still be displayed to the user.

Another solution would be to use something like this at the beginning of your script, when you are on the production server :

ini_set('display_errors', 'Off');

That way, no error is ever displayed to the end-user (they don't need to see those, and probably wouldn't understand), even in situations you didn't think about ; and it's easy to get all the errors displayed on your development machine : just on line to comment ;-)

Note : in production, if you can set the configuration like you want, there is the possibility to log errors to a file ; that way, you can check those, and not have them displayed.