Consistent Results from Google API

Question

Using the Google API to determine the County from one of two choices (by latitude and longitude) is giving inconsistent results. One gives the County under the key of 2; the other with the key of 4. How can I fetch the needed information with this inconsistency?

I have used Json only a couple times so perhaps I've misunderstood how values are retrieved so here is my PHP function for parsing it:

function getCounty($LatLong) {
    global $googlekey;
    $url = "https://maps.googleapis.com/maps/api/geocode/json?latlng=$LatLong&key=$googlekey";
    $json = @file_get_contents($url);
    $data = json_decode($json);
    $status = $data->status;
    if ($status === "OK") :
        //return $data->results[0]->address_components[2]->long_name;
        return $data->results[0]->address_components[4]->long_name;
    else :
        return FALSE;
    endif;
}

In other words, to get one County name it needs this:

return $data->results[0]->address_components[2]->long_name;

. . . while it needs this to get the other County name:

return $data->results[0]->address_components[4]->long_name;

This defeats the purpose of trying to find dynamically in which County it is being used!

Using Json to parse it, gives this (a partial snippet of the output) for one county where the key for the County is 2

[2] => stdClass Object
    (
        [long_name] => Santa Cruz County
        [short_name] => Santa Cruz County
        [types] => Array
            (
                [0] => administrative_area_level_2
                [1] => political
            )

    )

[3] => stdClass Object
    (
        [long_name] => California
        [short_name] => CA
        [types] => Array
            (
                [0] => administrative_area_level_1
                [1] => political
            )

    )

[4] => stdClass Object
    (
        [long_name] => United States
        [short_name] => US
        [types] => Array
            (
                [0] => country
                [1] => political
            )

    )

. . . and this gives the key for the other County as 4:

[2] => stdClass Object
    (
        [long_name] => West Valley
        [short_name] => West Valley
        [types] => Array
            (
                [0] => neighborhood
                [1] => political
            )

    )

[3] => stdClass Object
    (
        [long_name] => San Jose
        [short_name] => San Jose
        [types] => Array
            (
                [0] => locality
                [1] => political
            )

    )

[4] => stdClass Object
    (
        [long_name] => Santa Clara County
        [short_name] => Santa Clara County
        [types] => Array
            (
                [0] => administrative_area_level_2
                [1] => political
            )

    )

Having said that, is there a way to get the County directly from the IP address? I saw somewhere that Google frowns on it but then within the Google API documentation, I saw references to use the IP but no examples so it was vague on how it might be done.

Answer 1

As @enricog said; What you want is to extract the value according a specific type.

Based on the documentation: https://developers.google.com/maps/documentation/geocoding/intro?hl=de#Types

Here's an idea of what you can do:

$data = json_decode($json);
$counties = [];

foreach($data->results as $result){
    $counties = array_merge($counties, array_filter($result->address_components, function ($address) { 
        return in_array('administrative_area_level_2', $address->types);
    })); 
}


$counties = array_map(function ($county) { 
    return $county->long_name;
}, $counties); 

echo implode(', ', $counties);

https://3v4l.org/UUboK

I don't work with google map API, I have no idea if you can have multiple counties in the response. The JSON structure allow it and I guess, depend of what the request is, it may have some. I have added fictional values to the json to validate the principle.

I believe this snippet can be optimized. But at least it will return every single counties from the response and you won't get an undefined index

Review

After playing a bit with the API I can now answer a bit more precisely. But this is only my constatation. When you request the location it will returns many known place that are close to your location. The first result should always be the closest to you.

Note from Google : Reverse geocoding is not an exact science. The geocoder will attempt to find the closest addressable location within a certain tolerance.

Based on that, we can optimize the code to have only one result which should be the correct county.

function getCounty($LatLong) {
    // do stuff
    $data = json_decode($json);
    $counties = [];

    if(!empty($data->results)){
        $counties = array_merge($counties, array_filter($data->results[0]->address_components, function ($address) { 
            return in_array('administrative_area_level_2', $address->types);
        })); 
    }

    if(!empty($counties)){
        return reset($counties)->long_name; // https://stackoverflow.com/a/3771228/8068675
    }
    return 'No county found';
}

https://3v4l.org/5RGOe
I did read, you where not using PHP 7. However I will keep this code with PHP 7 compatibility since php 5.6 is no longer supported and shouldn't be used anymore.

Answer 2

Using cbaconnier's looping and limiting it to run only once, it is now working! Note that $counties = []; worked on my local PHP 7.2 development system but not on the older version of PHP on the live server so I changed it to $counties = array();.

Thank you for all the help. Now if there is a way to do it directly from the IP, I would like to know what it is!

function getCounty($LatLong) {
    global $googlekey;

    $url = "https://maps.googleapis.com/maps/api/geocode/json?latlng=$LatLong&key=$googlekey";
    $json = @file_get_contents($url);
    $data = json_decode($json);
    $status = $data->status;
    if ($status === "OK") :
        //$counties = []; // for later PHP versions but does not work on live server
        $counties = array();

        $i = 0;
        foreach (range(1, 1)  as $i) :
            foreach($data->results as $result) :
                if ($i++ > 1) break;
                $counties = array_merge($counties, array_filter($result->address_components, function ($address) { 
                    return in_array('administrative_area_level_2', $address->types);
                })); 
            endforeach;
        endforeach;

        $counties = array_map(function ($county) { 
            return $county->long_name;
        }, $counties);

        return $counties[0];

    else :
        return FALSE;
    endif;
}