Dynamically add fields to http_build_query - php

Question

I have built an API that I want to test. By that reason I'm building a simple client to try out the different features (CRUD). Below is the function for updating a producer, which works fine. However, I also want to be able to update parts of a producer, e.g. address (/producers/8?method=put&address=milkyway).
The array producer always contains the same elements (name, address, zipcode etc) but I only want to update the producer with the elements in the array which contains of anything. What I mean with that is that if for example the name element in the array is empty then name shouldn't be included in *http_build_query*. If only the name element contains of anything then only name should be updated.
So, let's say that the array (except for id that of course is mandatory) contains of address. How can I dynamically add only that to *http_build_query* ?
Thanks in advance!
public function UpdateProducer($producer) {
$url = 'http://localhost/webbteknik2/Labb2/api/v1/producers/ . $producer['id'] . '?method=put';
$data = http_build_query(array(
'name' => $producer['name'],
'address' => $producer['address'],
'zipcode' => $producer['zipcode'],
'town' => $producer['town'],
'url' => $producer['url'],
'imgurl' => $producer['imgurl'],
'latitude' => $producer['latitude'],
'longitude' => $producer['longitude'],
));
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
...
the rest of the curl code
}
Note: I know this is bad coding in many ways, but as I said I only, asap want to be able to test the CRUD functionality through the client.

Answer 1

use array_filter to remove the empty elements....
$params = array(
'name' => $producer['name'],
'address' => $producer['address'],
'zipcode' => $producer['zipcode'],
'town' => $producer['town'],
'url' => $producer['url'],
'imgurl' => $producer['imgurl'],
'latitude' => $producer['latitude'],
'longitude' => $producer['longitude'],
);
$data = http_build_query(array_filter($params, 'is_null'));