SWI-Prolog HTTP support library

This directory provides the SWI-Prolog libraries for accessing and providing HTTP services.

Client library

The main client library is library(http/http_open), which can open both HTTP and HTTPS connections and handle all request methods.

Server library

The main server libarys are

• library(http/thread_httpd) implements the server
• library(http/http_dispatch) implements binding locations predicates
• library(http/http_unix_daemon) implements integration in various Unix server managers and in general provides a suitable entry point for HTTP servers on Unix.
• library(http/html_write) implements generating HTML
• library(http/http_json) implements reading and writing JSON documents.

Requirements

This library uses functionality from the ssl package to support HTTPS, the sgml package to read XML/HTML and the clib package for various extensions.

Prolog files

html_head.pl  -- Automatic inclusion of CSS and scripts links
html_quasiquotations.pl  -- HTML quasi quotations
html/4	The predicate html/4 implements HTML quasi quotations.
html_write.pl  -- Write HTML text
html/3	Generate HTML from Content.
html_begin/3	For html_begin//1, Env is a term Env(Attributes); for html_end//1 it is the plain environment name.
html_current_option/1	True if Option is an active option for the HTML generator.
html_end/3	For html_begin//1, Env is a term Env(Attributes); for html_end//1 it is the plain environment name.
html_meta/1	This directive can be used to declare that an HTML rendering rule takes HTML content as argument.
html_post/4	Reposition HTML to the receiving Id.
html_print_length/2	Determine the content length of a token list produced using html//1.
html_quoted/3	Quote the value for normal (CDATA) text.
html_quoted_attribute/3	Quote the value according to the rules for tag-attributes included in double-quotes.
html_receive/3	Receive posted HTML tokens.
html_receive/4	This extended version of html_receive//1 causes Handler to be called to process all messages posted to the channal at the time output is generated.
html_root_attribute/4	Add an attribute to the HTML root element of the page.
html_set_options/1	Set options for the HTML output.
layout/3	Define required newlines before and after tags.
page/3	Generate a page including the HTML <!DOCTYPE> header.
page/4	Generate a page including the HTML <!DOCTYPE> header.
print_html/1	Print list of atoms and layout instructions.
print_html/2	Print list of atoms and layout instructions.
reply_html_page/2	Provide the complete reply as required by http_wrapper.pl for a page constructed from Head and Body.
reply_html_page/3	Provide the complete reply as required by http_wrapper.pl for a page constructed from Head and Body.
xhtml_ns/4	Demand an xmlns:id=Value in the outer html tag.
http_authenticate.pl  -- Authenticate HTTP connections using 401 headers
http_authenticate/3	True if Request contains the information to continue according to Type.
http_authorization_data/2	Decode the HTTP Authorization header.
http_current_user/3	True when User is present in the htpasswd file File and Fields provides the additional fields.
http_read_passwd_file/2	Read a password file.
http_write_passwd_file/2	Write password data Data to File.
authenticate/3	Plugin for library(http_dispatch) to perform basic HTTP authentication.
http_client.pl  -- HTTP client library
http_cors.pl  -- Enable CORS: Cross-Origin Resource Sharing
cors_enable/0	Emit the HTTP header Access-Control-Allow-Origin using domains from the setting http:cors.
cors_enable/2	CORS reply to a Preflight OPTIONS request.
http_digest.pl  -- HTTP Digest authentication
authenticate/3	Plugin for library(http_dispatch) to perform basic HTTP authentication.
authenticate_client/2	This hooks is called by http_open/3 with the following Action value:.
http_digest_challenge/4	Generate the content for a 401 WWW-Authenticate: Digest header field.
http_digest_password_hash/4	Compute the password hash for the HTTP password file.
http_digest_response/5	Formulate a reply to a digest authentication request.
http_parse_digest_challenge/2	Parse the value of an HTTP WWW-Authenticate header into a list of Name(Value) terms.
http_dispatch.pl  -- Dispatch requests in the HTTP server
http_404/2	Reply using an "HTTP 404 not found" page.
http_current_handler/2	True if Location is handled by Closure.
http_current_handler/3	Resolve the current handler and options to execute it.
http_delete_handler/1	Delete handler for Spec.
http_dispatch/1	Dispatch a Request using http_handler/3 registrations.
http_handler/3	Register Closure as a handler for HTTP requests.
http_link_to_id/3	HREF is a link on the local server to a handler with given ID, passing the given Parameters.
http_location_by_id/2	True when Location represents the HTTP path to which the handler with identifier ID is bound.
http_redirect/3	Redirect to a new location.
http_reload_with_parameters/3	Create a request on the current handler with replaced search parameters.
http_reply_file/3	Options is a list of.
http_request_expansion/2	Register Goal for expanding the HTTP request handler.
http_safe_file/2	True if FileSpec is considered safe.
http_switch_protocol/2	Send an "HTTP 101 Switching Protocols" reply.
http_dyn_workers.pl  -- Dynamically schedule HTTP workers.
schedule_workers/1	Called if there is no immediately free worker to handle the incomming request.
http_exception.pl  -- Map Prolog exceptions to HTTP errors
bad_request_error/2	If an exception of the term error(Formal, context(Stack, Context)) is caught and subsumes_term(ContextTemplate, Context) is true, translate the exception into an HTTP 400 exception.
in_or_exclude_backtrace/2	Remove the stacktrace from the exception, unless setting http:client_backtrace is true.
map_exception_to_http_status/4	Map certain exceptions to HTTP status codes.
http_header.pl  -- Handling HTTP headers
http_hook.pl  -- HTTP library hooks
convert_parameter/3	Hook to execute a step in the HTTP parameter conversion process.
http_connection_over_proxy/6	Try to connect to the host Endpoint via Proxy for the purposes of retrieving the resource identified by URLParts.
http_host.pl  -- Obtain public server location
http_json.pl  -- HTTP JSON Plugin module
post_data_hook/3	Hook implementation that allows http_post_data/3 posting JSON objects using one of the forms below.
http_convert_data/4	Hook implementation that supports reading JSON documents.
http_read_json/2	Extract JSON data posted to this HTTP request.
http_read_json/3	Extract JSON data posted to this HTTP request.
http_read_json_dict/2	Similar to http_read_json/2,3, but by default uses the version 7 extended datatypes.
http_read_json_dict/3	Similar to http_read_json/2,3, but by default uses the version 7 extended datatypes.
is_json_content_type/1	True if ContentType is a header value (either parsed or as atom/string) that denotes a JSON value.
json_type/1	True if MediaType is a JSON media type.
reply_json/1	Formulate a JSON HTTP reply.
reply_json/2	Formulate a JSON HTTP reply.
reply_json_dict/1	As reply_json/1 and reply_json/2, but assumes the new dict based data representation.
reply_json_dict/2	As reply_json/1 and reply_json/2, but assumes the new dict based data representation.
http_multipart_plugin.pl  -- Multipart form-data plugin
http_convert_data/4	Convert multipart/form-data messages for http_read_data/3.
http_open.pl  -- HTTP client library
http_parameters.pl  -- Extract parameters (GET and POST) from HTTP requests
http_convert_parameter/4	Conversion of an HTTP form value.
http_convert_parameters/2	Implements the parameter translation of http_parameters/2 or http_parameters/3.
http_convert_parameters/3	Implements the parameter translation of http_parameters/2 or http_parameters/3.
http_parameters/2	Get HTTP GET or POST form-data, applying type validation, default values, etc.
http_parameters/3	Get HTTP GET or POST form-data, applying type validation, default values, etc.
http_path.pl  -- Abstract specification of HTTP server locations
http_server_files.pl  -- Serve files needed by modules from the server
serve_files_in_directory/2	Serve files from the directory Alias from the path-info from Request.
http_session.pl  -- HTTP Session management
http_ssl_plugin.pl  -- SSL plugin for HTTP libraries
http_connection_over_proxy/6	Facilitate an HTTPS connection via a proxy using HTTP CONNECT.
http_protocol_hook/5	Hook for http_open/3 to connect to an HTTPS (SSL-based HTTP) server.
open_options/2	Implementation of the multifile hook http:open_options/2 used by library(http/http_open).
ssl_server_create_hook/3	Extensible predicate that is called once after creating an HTTPS server.
ssl_server_open_client_hook/3	Extensible predicate that is called before each connection that the server negotiates with a client.
accept_hook/2	Implement the accept for HTTPS connections.
make_socket_hook/3	Hook into http_server/2 to create an SSL server if the option ssl(SSLOptions) is provided.
http_stream.pl  -- HTTP Streams
http_unix_daemon.pl  -- Run SWI-Prolog HTTP server as a Unix system daemon
sni_options/2	Hook to provide Server Name Indication (SNI) for TLS servers.
http_certificate_hook/3	Hook called before starting the server if the --https option is used.
http_daemon/0	Start the HTTP server as a daemon process.
http_daemon/1	Start the HTTP server as a daemon process.
http_server_hook/1	Hook that is called to start the HTTP server.
http_wrapper.pl  -- Server processing of an HTTP request
hub.pl  -- Manage a hub for websockets
current_hub/2	True when there exists a hub Hub with Name.
hub_add/3	Add a WebSocket to the hub.
hub_broadcast/2	Send Message to all websockets associated with Hub for which call(Condition, Id) succeeds.
hub_broadcast/3	Send Message to all websockets associated with Hub for which call(Condition, Id) succeeds.
hub_create/3	Create a new hub.
hub_send/2	Send message to the indicated ClientId.
jquery.pl  -- Provide JQuery
js_grammar.pl  -- JavaScript grammar
js_token/3	Matches and classifies the next JavaScript token.
js_write.pl  -- Utilities for including JavaScript
json.pl  -- Reading and writing JSON serialization
atom_json_dict/3	Convert between textual representation and a JSON term represented as a dict.
atom_json_term/3	Convert between textual representation and a JSON term.
is_json_term/1	True if Term is a json term.
is_json_term/2	True if Term is a json term.
json_read/2	Read next JSON value from Stream into a Prolog term.
json_read/3	Read next JSON value from Stream into a Prolog term.
json_read_dict/2	Read a JSON object, returning objects as a dicts.
json_read_dict/3	Read a JSON object, returning objects as a dicts.
json_write/2	Write a JSON term to Stream.
json_write/3	Write a JSON term to Stream.
json_write_dict/2	Write a JSON term, represented using dicts.
json_write_dict/3	Write a JSON term, represented using dicts.
mimepack.pl  -- Create a MIME message
mime_pack/3	Pack a number of inputs into a MIME package using a specified or generated boundary.
mimetype.pl  -- Determine mime-type for a file
charset/3	Hook that determines the Charset for File that has media type MediaType.
mime_extension/2	Hook that is called by file_mime_type/2 before the default table is examined.
file_content_type/2	True if File should be served using ContentType: ContentType.
file_content_type/3	True if File should be served using ContentType: ContentType.
file_mime_type/2	True when MimeType is the mime-type to be used for sending FileName.
term_html.pl  -- Represent Prolog terms as HTML
thread_httpd.pl  -- Threaded HTTP server
schedule_workers/1	Hook called if a new connection or a keep-alive connection cannot be scheduled immediately to a worker.
http_add_worker/2	Add a new worker to the HTTP server for port Port.
http_close_connection/1	Close connection associated to Request.
http_current_server/2	True if Goal is the goal of a server at Port.
http_current_worker/2	True if ThreadID is the identifier of a Prolog thread serving Port.
http_enough_workers/3	Check that we have enough workers in our queue.
http_requeue/1	Re-queue a connection to the worker pool.
http_server/2	Create a server at Port that calls Goal for each parsed request.
http_server_property/2	True if Property is a property of the HTTP server running at Port.
http_spawn/2	Continue this connection on a new thread.
http_stop_server/2	Stop the indicated HTTP server gracefully.
http_workers/2	Query or set the number of workers for the server at this port.
message_level/2	Determine the message stream used for exceptions that may occur during server_loop/5.
websocket.pl  -- WebSocket support
http_open_websocket/3	Establish a client websocket connection.
http_upgrade_to_websocket/3	Create a websocket connection running call(Goal, WebSocket), where WebSocket is a socket-pair.
ws_close/3	Close a WebSocket connection by sending a close message if this was not already sent and wait for the close reply.
ws_open/3	Turn a raw TCP/IP (or any other binary stream) into a websocket stream.
ws_property/2	True if Property is a property WebSocket.
ws_receive/2	Receive the next message from WebSocket.
ws_receive/3	Receive the next message from WebSocket.
ws_send/2	Send a message over a websocket.