http_server.pl -- HTTP server libraryhttp_server.pl -- HTTP server libraryThis library combines the core server functionality provided by several libraries that are needed by almost any web server. It exports the commonly used predicates from library(http/thread_httpd), library(http/http_dispatch), library(http/http_wrapper), library(http/http_parameters), library(http/html_write), library(http/http_json), and library(http/http_dyn_workers).
http_server(+Options) is detThe following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.
reply_html_page(:Head, :Body) is det reply_html_page(+Style, :Head, :Body) is detContent-type is
provided by html_current_option/1.
html_meta(+Heads) is dethtml. For example:
:- html_meta
page(html,html,?,?).
http_handler(+Path, :Closure, +Options) is det'/home.html' or a term Alias(Relative).
Where Alias is associated with a concrete path using location/3
and resolved using http_absolute_location/3. Relative can be a
single atom or a term `Segment1/Segment2/...`, where each element is
either an atom or a variable. If a segment is a variable it matches
any segment and the binding may be passed to the closure. If the
last segment is a variable it may match multiple segments. This
allows registering REST paths, for example:
:- http_handler(root(user/User), user(Method, User),
[ method(Method),
methods([get,post,put])
]).
user(get, User, Request) :-
...
user(post, User, Request) :-
...
If an HTTP request arrives at the server that matches Path, Closure is called as below, where Request is the parsed HTTP request.
call(Closure, Request)
Options is a list containing the following options:
Basic HTTP authentication.Transfer-encoding: chunked if the client allows for it.true on a prefix-handler (see prefix), possible children
are masked. This can be used to (temporary) overrule part of the
tree.methods([Method]). Using method(*) allows for all methods.
:- http_handler(/, http_404([index('index.html')]),
[spawn(my_pool),prefix]).
infinite, default or a positive number (seconds). If
default, the value from the setting http:time_limit is
taken. The default of this setting is 300 (5 minutes). See
setting/2.Note that http_handler/3 is normally invoked as a directive and processed using term-expansion. Using term-expansion ensures proper update through make/0 when the specification is modified.
is_json_content_type(+ContentType) is semidet http_read_json_dict(+Request, -Dict) is det http_read_json_dict(+Request, -Dict, +Options) is det http_read_json_dict(+Request, -Dict) is det http_read_json_dict(+Request, -Dict, +Options) is det reply_json_dict(+JSONTerm) is det reply_json_dict(+JSONTerm, +Options) is det reply_json_dict(+JSONTerm) is det reply_json_dict(+JSONTerm, +Options) is det http_parameters(+Request, ?Parms) is det http_parameters(+Request, ?Parms, :Options) is detcall(Goal, A, Declarations).The attribute_declarations hook allows sharing the declaration of attribute-properties between many http_parameters/3 calls. In this form, the requested attribute takes only one argument and the options are acquired by calling the hook. For example:
...,
http_parameters(Request,
[ sex(Sex)
],
[ attribute_declarations(http_param)
]),
...
http_param(sex, [ oneof(male, female),
description('Sex of the person')
]).
http_parameters(+Request, ?Parms) is det http_parameters(+Request, ?Parms, :Options) is detcall(Goal, A, Declarations).The attribute_declarations hook allows sharing the declaration of attribute-properties between many http_parameters/3 calls. In this form, the requested attribute takes only one argument and the options are acquired by calling the hook. For example:
...,
http_parameters(Request,
[ sex(Sex)
],
[ attribute_declarations(http_param)
]),
...
http_param(sex, [ oneof(male, female),
description('Sex of the person')
]).
http_current_request(-Request) is semidet http_peer(+Request, -PeerIP:atom) is semidetFastly-client-ipX-real-ipX-forwarded-for http_server(:Goal, :Options) is detAF_UNIX). See socket_create/2.main thread.
If you need to control resource usage you may consider the
spawn option of http_handler/3 and library(thread_pool).true (default false), do not print an informational
message that the server was started.A typical initialization for an HTTP server that uses http_dispatch/1 to relay requests to predicates is:
:- use_module(library(http/thread_httpd)).
:- use_module(library(http/http_dispatch)).
start_server(Port) :-
http_server(http_dispatch, [port(Port)]).
Note that multiple servers can coexist in the same Prolog process. A notable application of this is to have both an HTTP and HTTPS server, where the HTTP server redirects to the HTTPS server for handling sensitive requests.
The following predicates are exported, but not or incorrectly documented.
http_location_by_id(Arg1, Arg2) http_404(Arg1, Arg2) http_delete_handler(Arg1) http_stop_server(Arg1, Arg2) http_workers(Arg1, Arg2) http_current_handler(Arg1, Arg2, Arg3) http_redirect(Arg1, Arg2, Arg3) html(Arg1, Arg2, Arg3) http_spawn(Arg1, Arg2) http_current_server(Arg1, Arg2) http_reload_with_parameters(Arg1, Arg2, Arg3) http_current_handler(Arg1, Arg2) http_reply_file(Arg1, Arg2, Arg3) http_add_worker(Arg1, Arg2) http_server_property(Arg1, Arg2) http_link_to_id(Arg1, Arg2, Arg3) http_switch_protocol(Arg1, Arg2) http_request_expansion(Arg1, Arg2) http_dispatch(Arg1) http_current_worker(Arg1, Arg2)