JSON to PHP array / Empty json

So I have a php file which generates json data based on different "params"

.php?params=foo,bar,blaa

(some sort of API?) I have checked it, and it returns valid json data. Mostly I'm using this file for jQuery/ajax -calls, but this time I want't this data to php array.

?param=comments returns all comments from database (because no extra params given like userid, time etc..). Different [GET]params make it to return different data. And yes - it works.

[{"type":"comment","commentid":"789006","userid":"235541","to_postid":"4003","content":"Hello","commented":"2014-07-01 13:54:54"}]

I return it like this:

// Output
header('Content-Type: application/json');
echo json_encode($result);

$result is array containing all data. This is how I push data (nothing wrong here?)

$result[] = array(
    "type"=>"comment",
    "commentid"=>$foo->commentid,
    "userid"=>$foo->userid,
    "to_postid"=>$foo->to_postid,
    "content"=>$foo->content,
    "commented"=>$foo->commented
);

In PHP I'm trying to use

json_decode(file_get_contents(HTTP_PATH."foo/myFile.php?params=comments"),true);

HTTP_PATH is just a defined variable for my localhost (using XAMPP) path

var_dump(file_get_content(...));

returns

string(2) "[]"

For some reason JSON is empty. Can't get it to php array. I have tried various things. Also checked whitespaces, file path, charset, error_log ... Also posted this problem to here (not in english): http://www.ohjelmointiputka.net/keskustelu/28188-json-php-array/sivu-1

json_decode(file_get_contents(HTTP_PATH."file/myFile.php?params=comments"),true); json_decode(file_get_contents(HTTP_PATH."file/myFile.php?params=comments"));

If I add $result[] = array("Hello!");

It will be displayed http://gyazo.com/81a96c8c5570e5fddacb47038bfa01ff

Hope u understood. What am I doing wrong??