// Given an array of key=>value mappings, save that data to the configuration file
function hello_world_save_config($config = array()) {
  $file     = HELLO_WORLD_CONFIGFILE;
  $contents = json_encode($config);            // Encodes the array into a valid JSON string

  return file_put_contents($file, $contents);  // Saves the JSON string into the configuration JSON file
}

// Load plugin configuration from the JSON file as an array
function hello_world_get_config() {
  $file     = HELLO_WORLD_CONFIGFILE;
  $contents = file_get_contents($file);
  $json     = json_decode($contents);    // Decodes the string
  $config   = (array) $json;             // Converts the object into a PHP array

  return $config;
}