ZF3 development of RestAPI: handling Post request for - zend-framework3

Question

I am new to Zf3, and developing Email Restful API.
having difficulties in handling request. I can't get POST parameters.i think there is some problem in module.config.php > 'router'
Questions
1 How can I get POST variables from request.
2 I found it when I request page (using Postman)
- if I passes ID, controller call get($id) method
- if I POST variables controller calls Create($data) function.
--is this always the case ? and is it good to write zendEmail code inside create($data) method
.
bwsmail controller
(create function)
public function create($data)
{
echo $this->getRequest()->getPost('id', "no value");
// Output
// this returns no value
echo $this->getRequest();
// Output
//POST http://localhost:8080/bwsmail/mail?id=123456789 HTTP/1.1
//Cookie: PHPSESSID=p5i7o8lm2ed0iocdhkc8jvos01
//Cache-Control: no-cache
//Postman-Token: ccaf5b37-02a2-4537-bf3f-c1dc419d8ceb
//User-Agent: PostmanRuntime/7.6.1
//Accept: */*
//Host: localhost:8080
//Accept-Encoding: gzip, deflate
//Content-Length: 0
//Connection: keep-alive
$response = $this->getResponseWithHeader()->setContent( __METHOD__.' create new item of data :<b>'.'</b>');
return $response;
}
module.config.php (route)
'bwsmail' => [
'type' => Literal::class,
'options' => [
'route' => '/bwsmail',
'defaults' => [
'controller' => Controller\BwsMailController::class,
]
],
'may_terminate' => true,
'child_routes' => [
'mail' => [
'type' => 'segment',
'options' => [
'route' => '/mail[/:id]',
'constraints'=>
[
'id' => '[0-9a-zA-Z]+',
],
'defaults' => [
'controller' => Controller\BwsMailController::class,
]
],
],
],
],

Answer 1

if BwsMailController extends AbstractController or AbstractRestfulController you can simply: $this->params()->fromRoute() or ->fromQuery() if you're using a get string. For example:
$routeParamId = $this->params()->fromRoute('id', null);
This gets the parameter id as it is defined in the route configuration. If it's not set, it will default to null.
If you have a GET url, something like: site.com/mail?id=123, then you do:
$getParamId = $this->params()->fromQuery('id', null); // sets '123' in var
More options are available, have a good read of the routing documentation.