Request / Reply , how should one initiate the actual sending of the transmission?

Question

I'm working on Language level interfaces to web API's. These libraries are of course built around existing HTTP Request/Reply interfaces. I see myself as having a few options

submit method on the request object e.g

my $req = Request->new( ... );

my $response = $req->submit; # returns response

my $res2     = $req->submit; # sends the same request again

lazy request accessor

my $req = Request->new( ... );

my $response = $req->response; # returns a reference to the response

my $res2     = $req->response; # doesn't send again, just returns the reference

$req->clear_response;          # clears the response value

my $res3     = $req->response; # sends again because no response exists

These are the 2 options I'm thinking of. I have seen more examples of the former but I'm not sure if there's a reason why. Do you have any preferences on which style interface? or are there other ways I'm not thinking of? Overall I'm trying to discern what the best API is to retrieve the response.

Answer 1

Most people who want to keep a reference to the same response around will just save $response somewhere. Your second option violates the single responsibility principle for the method and makes it unpredictable. Sometimes response returns an old reference and sometimes it sends a new request. It also adds additional steps if you want to send another request. It's obvious in a small function, but if a lot of code intervenes between requests, you won't know for sure if you need or want to do a clear first in order to generate a new response.

If you are set on caching the response in the Request object, I would at least make it a separate name from the one that submits it. For example, $response = $req->submit for actually submitting it, and $req->response if you just want to retrieve the last cached response.