Usage
==========
The main predicate of the library is http_listen/2, which needs a port number
- (usually 80) and a list of handlers. A handler is a compund term with the functor
+ (usually 80) and a list of handlers. A handler is created using the http_route/3 predicate
as one HTTP method (in lowercase) and followed by a Route Match and a predicate
which will handle the call.
parameter_handler(User, Request, Response) :-
http_body(Response, text(User)).
- http_listen(7890, [
- get(echo, text_handler), % GET /echo
- post(user/User, parameter_handler(User)) % POST /user/<User>
- ]).
+ server :-
+ http_route(get(echo), text_handler, TextHandler),
+ http_route(post(user/User), parameter_handler(User), ParameterHandler),
+ http_listen(7890, [
+ TextHandler, % GET /echo
+ ParameterHandler % POST /user/<User>
+ ]).
Every handler predicate will have at least 2-arity, with Request and Response.
Although you can work directly with http_request and http_response terms, it is
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
:- module(http_server, [
+ http_route/3,
http_listen/2,
http_headers/2,
http_status_code/2,
url_decode//1
]).
+:- meta_predicate http_route(?, 2, ?).
+
:- use_module(library(sockets)).
:- use_module(library(dcgs)).
:- use_module(library(format)).
:- use_module(library(time)).
:- use_module(library(crypto)).
+http_route(Path, Handler, MetaHandler) :-
+ Path =.. [Method, Pattern],
+ MetaHandler =.. [Method, Pattern, Handler].
+
% Server initialization
http_listen(Port, Handlers) :-
must_be(integer, Port),
HttpResponse = http_response(_, _, _),
(call(Handler, HttpRequest, HttpResponse) ->
send_response(Stream, HttpResponse)
- ; format(Stream, "HTTP/1.0 500 Internal Server Error\r\n\r\n")
+ ; format(Stream, "HTTP/1.0 500 Internal Server Error\r\n\r\n", [])
)
)
; format(Stream, "HTTP/1.0 404 Not Found\r\n\r\n", [])