/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: jan@swi-prolog.org WWW: http://www.swi-prolog.org Copyright (c) 2024, SWI-Prolog Solutions b.v. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ :- module(htmx, [ reply_htmx/1, % +HTML reply_htmx/2, % +HTML, +Request htmx_oob//2 % ++Id, :HTML ]). :- use_module(library(http/html_write)). /** Support htmx.org Quoted from htmx.org: > [htmx](https://htmx.org) gives you access to AJAX, CSS Transitions, > WebSockets and Server Sent Events directly in HTML, using attributes, > so you can build modern user interfaces with the simplicity and power > of hypertext The idea behind htmx is to allow adding attributes to any HTML element that cause an HTTP request. The HTTP response is typically a (short) HTML fragment that extends or replaces an element on the page. This allows us to program a most functionality interactive seen in modern web applications using the powerful SWI-Prolog HTML generation framework rather than having to write a JSON backend and accompanying JavaScript frontend that runs in the browser. Below is a minimal, yet fully functional application ``` :- use_module(library(http/http_server)). :- use_module(library(http/htmx)). :- use_module(library(main)). :- initialization(main, main). main(_Argv) :- http_server([port(8080)]), thread_get_message(quit). http:location(htmx, root(htmx), []). :- http_handler(root(.), home, []). home(_Request) :- reply_html_page( [ title('HTMX demo'), script(src('https://unpkg.com/htmx.org'), []) ], [ button([ 'hx-post'('/htmx/clicked'), 'hx-swap'('outerHTML') ], 'Click me') ]). :- http_handler(htmx(clicked), reply_htmx(\clicked), []). clicked --> html('Thanks for clicking me!'). ``` HTMX requires no dedicated support from the server. This library provides reply_htmx/1,2 to reply with a single HTML element rather than an entire page. Future versions of this library may provide some additional utility predicates. */ :- html_meta reply_htmx(html), reply_htmx(html, +), htmx_oob(+, html, ?, ?). %! reply_htmx(+HTML) is det. %! reply_htmx(+HTML, +Request) is det. % % Reply a plain HTML element as opposed to a complete HTML page as % created using reply_html_page/2,3. While reply_htmx/1 is to be used % in a normal HTTP handler (route), reply_htmx/2 may be registered % directly in the http_handler/3 declaration to deal with simple cases % where we do not need the `Request` data. reply_htmx(HTML) :- phrase(html(HTML), Tokens), format('Content-type: text/html~n~n', []), print_html(Tokens). reply_htmx(HTML, _Request) :- reply_htmx(HTML). %! htmx_oob(++Target, :HTML)// is det. % % Emit an htmx out-of-band element. HTML is used to swap the % content of the DOM element with id Target. htmx_oob(Target, HTML) --> html(div([id(Target), 'hx-swap-oob'(true)], HTML)).