获得特定服务的速率 - EasyPost

Question

I currently have EasyPost creating a shipment. When I create the shipment it provides me with all the available services and rates.

I would like to dynamically select service and only return that rate.

I originally would read through the array using the index number (I guess that how to describe it).

The problem with this is every time I create a new shipment the order of the rates array changes so what would have been $shipment->rates[0]['rate'] would be express and then the next time first class.

I want to create a shipment with "Express" and only return that rate.

Any advice would be appreciated.

Here is my code:

$name = $this->thiscustomer->cust_first . ' ' . $this->thiscustomer->cust_first;
$street_1 = $this->thiscustomer->street_1;
$street_2 = $this->thiscustomer->street_2;
$city = $this->thiscustomer->city;
$state = $this->thiscustomer->state;
$zip = $this->thiscustomer->zip;


$weight = $this->weight;
    $packaging = $this->packaging;
    $service = $this->service;
    $caddress = $this->consultant->address;
    $cstreet_1 = $this->consultant->street_1;
    $cstreet_2 = $this->consultant->street_2;
    $ccity = $this->consultant->city;
    $cstate = $this->consultant->state;
    $czip = $this->consultant->zip;
    $cname = $this->consultant->first_name . ' ' . $this->consultant->last_name;
    $cuser_id = $this->consultant->user_id;




require_once(dirname(__FILE__) . '/lib/easypost.php');
\EasyPost\EasyPost::setApiKey('KUk4fZUI6YaYc1h0FiIXFw');


$shipment = \EasyPost\Shipment::create(array(
 'to_address' => array(
"name"    => $name,
"street1" => $street_1,
"street2" => $street_2,
"city"    => $city,
"state"   => $state,
"zip"     => $zip
 ),
 'from_address' => array(
"company" => $cname,
"street1" => $cstreet_1,
"street2" => $cstreet_2,
"city"    => $ccity,
"state"   => $cstate,
"zip"     => $czip
 ),
 'parcel' => array(
'weight' => $weight,
'predefined_package'=> $packaging
),
'rates' => array(
  'service' => $service
)

));

echo $shipment->rates[0]['rate']. '<br>';

Answer 1

In EasyPost's Getting Started Guide there is an example of buying a specific carrier+rate:

$shipment->buy($shipment->lowest_rate(array('USPS'), array('Express')));