1/*  Part of SWISH
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  2014-2018, VU University Amsterdam
    7			      CWI, Amsterdam
    8    All rights reserved.
    9
   10    Redistribution and use in source and binary forms, with or without
   11    modification, are permitted provided that the following conditions
   12    are met:
   13
   14    1. Redistributions of source code must retain the above copyright
   15       notice, this list of conditions and the following disclaimer.
   16
   17    2. Redistributions in binary form must reproduce the above copyright
   18       notice, this list of conditions and the following disclaimer in
   19       the documentation and/or other materials provided with the
   20       distribution.
   21
   22    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   23    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   24    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   25    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   26    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   27    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   28    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   29    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   30    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   31    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   32    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   33    POSSIBILITY OF SUCH DAMAGE.
   34*/
   35
   36:- module(swish_page,
   37	  [ swish_reply/2,			% +Options, +Request
   38	    swish_reply_resource/1,		% +Request
   39	    swish_page//1,			% +Options
   40
   41	    swish_navbar//1,			% +Options
   42	    swish_content//1,			% +Options
   43
   44	    pengine_logo//1,			% +Options
   45	    swish_logo//1,			% +Options
   46
   47	    swish_resources//0,
   48	    swish_js//0,
   49	    swish_css//0
   50	  ]).   51:- use_module(library(http/http_open)).   52:- use_module(library(http/http_dispatch)).   53:- use_module(library(http/http_parameters)).   54:- use_module(library(http/http_header)).   55:- use_module(library(http/html_write)).   56:- use_module(library(http/js_write)).   57:- use_module(library(http/json)).   58:- use_module(library(http/http_json)).   59:- use_module(library(http/http_path)).   60:- if(exists_source(library(http/http_ssl_plugin))).   61:- use_module(library(http/http_ssl_plugin)).   62:- endif.   63:- use_module(library(debug)).   64:- use_module(library(time)).   65:- use_module(library(lists)).   66:- use_module(library(option)).   67:- use_module(library(uri)).   68:- use_module(library(error)).   69:- use_module(library(http/http_client)).   70
   71:- use_module(config).   72:- use_module(help).   73:- use_module(search).   74:- use_module(chat).   75:- use_module(authenticate).   76:- use_module(pep).   77
   78/** <module> Provide the SWISH application as Prolog HTML component
   79
   80This library provides the SWISH page  and   its  elements as Prolog HTML
   81grammer rules. This allows for server-side   generated  pages to include
   82swish or parts of swish easily into a page.
   83*/
   84
   85http:location(pldoc, swish(pldoc), [priority(100)]).
   86
   87:- http_handler(swish(.), swish_reply([]), [id(swish), prefix]).   88
   89:- multifile
   90	swish_config:logo//1,
   91	swish_config:title//1,
   92	swish_config:source_alias/2,
   93	swish_config:reply_page/1,
   94	swish_config:li_login_button//1.   95
   96%%	swish_reply(+Options, +Request)
   97%
   98%	HTTP handler to reply the  default   SWISH  page.  Processes the
   99%	following parameters:
  100%
  101%	  - code(Code)
  102%	  Use Code as initial code. Code is either an HTTP url or
  103%	  - url(URL)
  104%	  Download code from URL.  As code(URL), but makes the browser
  105%	  download the source rather than the server.
  106%	  - background(Code)
  107%	  Similar to Code, but not displayed in the editor.
  108%	  - examples(Code)
  109%	  Provide examples. Each example starts with ?- at the beginning
  110%	  of a line.
  111%	  - q(Query)
  112%	  Use Query as the initial query.
  113%	  - show_beware(Boolean)
  114%	  Control showing the _beware limited edition_ warning.
  115%	  - preserve_state(Boolean)
  116%	  If `true`, save state on unload and restore old state on load.
  117
  118swish_reply(Options, Request) :-
  119	(   option(identity(_), Options)
  120	->  Options2 = Options
  121	;   authenticate(Request, Auth),
  122	    Options2 = [identity(Auth)|Options]
  123	),
  124	swish_reply2(Options2, Request).
  125
  126swish_reply2(Options, Request) :-
  127	option(method(Method), Request),
  128	Method \== get, Method \== head, !,
  129	swish_rest_reply(Method, Request, Options).
  130swish_reply2(_, Request) :-
  131	swish_reply_resource(Request), !.
  132swish_reply2(Options, Request) :-
  133	swish_reply_config(Request, Options), !.
  134swish_reply2(SwishOptions, Request) :-
  135	Params = [ code(_,	  [optional(true)]),
  136		   url(_,	  [optional(true)]),
  137		   label(_,	  [optional(true)]),
  138		   show_beware(_, [optional(true)]),
  139		   background(_,  [optional(true)]),
  140		   examples(_,    [optional(true)]),
  141		   q(_,           [optional(true)]),
  142		   format(_,      [oneof([swish,raw,json]), default(swish)])
  143		 ],
  144	http_parameters(Request, Params),
  145	params_options(Params, Options0),
  146	add_show_beware(Options0, Options1),
  147	add_preserve_state(Options1, Options2),
  148	merge_options(Options2, SwishOptions, Options3),
  149	source_option(Request, Options3, Options4),
  150	option(format(Format), Options4),
  151	swish_reply3(Format, Options4).
  152
  153swish_reply3(raw, Options) :-
  154	option(code(Code), Options), !,
  155	format('Content-type: text/x-prolog~n~n'),
  156	format('~s', [Code]).
  157swish_reply3(json, Options) :-
  158	option(code(Code), Options), !,
  159	option(meta(Meta), Options, _{}),
  160	option(chat_count(Count), Options, 0),
  161	reply_json_dict(json{data:Code, meta:Meta, chats:_{total:Count}}).
  162swish_reply3(_, Options) :-
  163	swish_config:reply_page(Options), !.
  164swish_reply3(_, Options) :-
  165	reply_html_page(
  166	    swish(main),
  167	    \swish_title(Options),
  168	    \swish_page(Options)).
  169
  170params_options([], []).
  171params_options([H0|T0], [H|T]) :-
  172	arg(1, H0, Value), nonvar(Value), !,
  173	functor(H0, Name, _),
  174	H =.. [Name,Value],
  175	params_options(T0, T).
  176params_options([_|T0], T) :-
  177	params_options(T0, T).
  178
  179%!	add_show_beware(+Options0, -Option) is det.
  180%
  181%	Add show_beware(false) when called with code, query or examples.
  182%	These are dedicated calls that do not justify this message.
  183
  184add_show_beware(Options0, Options) :-
  185	implicit_no_show_beware(Options0), !,
  186	Options = [show_beware(false)|Options0].
  187add_show_beware(Options, Options).
  188
  189implicit_no_show_beware(Options) :-
  190	option(show_beware(_), Options), !,
  191	fail.
  192implicit_no_show_beware(Options) :-
  193	\+ option(format(swish), Options), !,
  194	fail.
  195implicit_no_show_beware(Options) :-
  196	option(code(_), Options).
  197implicit_no_show_beware(Options) :-
  198	option(q(_), Options).
  199implicit_no_show_beware(Options) :-
  200	option(examples(_), Options).
  201implicit_no_show_beware(Options) :-
  202	option(background(_), Options).
  203
  204%!	add_preserve_state(+Options0, -Option) is det.
  205%
  206%	Add preserve_state(false) when called with code.
  207
  208add_preserve_state(Options0, Options) :-
  209	option(preserve_state(_), Options0), !,
  210	Options = Options0.
  211add_preserve_state(Options0, Options) :-
  212	option(code(_), Options0), !,
  213	Options = [preserve_state(false)|Options0].
  214add_preserve_state(Options, Options).
  215
  216
  217%%	source_option(+Request, +Options0, -Options)
  218%
  219%	If the data was requested  as   '/Alias/File',  reply using file
  220%	Alias(File).
  221
  222source_option(_Request, Options0, Options) :-
  223	option(code(Code), Options0),
  224	option(format(swish), Options0), !,
  225	(   uri_is_global(Code)
  226	->  Options = [url(Code),st_type(external)|Options0]
  227	;   Options = Options0
  228	).
  229source_option(_Request, Options0, Options) :-
  230	option(url(_), Options0),
  231	option(format(swish), Options0), !,
  232	Options = [st_type(external),download(browser)|Options0].
  233source_option(Request, Options0, Options) :-
  234	source_file(Request, File, Options0), !,
  235	option(path(Path), Request),
  236	(   source_data(File, String, Options1)
  237	->  append([ [code(String), url(Path), st_type(filesys)],
  238		     Options1,
  239		     Options0
  240		   ], Options)
  241	;   http_404([], Request)
  242	).
  243source_option(_, Options, Options).
  244
  245%%	source_file(+Request, -File, +Options) is semidet.
  246%
  247%	File is the file associated with a SWISH request.  A file is
  248%	associated if _path_info_ is provided.  If the file does not
  249%	exist, an HTTP 404 exception is returned.  Options:
  250%
  251%	  - alias(-Alias)
  252%	    Get the swish_config:source_alias/2 Alias name that
  253%	    was used to find File.
  254
  255source_file(Request, File, Options) :-
  256	option(path_info(PathInfo), Request), !,
  257	PathInfo \== 'index.html',
  258	(   path_info_file(PathInfo, File, Options)
  259	->  true
  260	;   http_404([], Request)
  261	).
  262
  263path_info_file(PathInfo, Path, Options) :-
  264	sub_atom(PathInfo, B, _, A, /),
  265	sub_atom(PathInfo, 0, B, _, Alias),
  266	sub_atom(PathInfo, _, A, 0, File),
  267	catch(swish_config:source_alias(Alias, AliasOptions), E,
  268	      (print_message(warning, E), fail)),
  269	Spec =.. [Alias,File],
  270	http_safe_file(Spec, []),
  271	absolute_file_name(Spec, Path,
  272			   [ access(read),
  273			     file_errors(fail)
  274			   ]),
  275	confirm_access(Path, AliasOptions), !,
  276	option(alias(Alias), Options, _).
  277
  278source_data(Path, Code, [title(Title), type(Ext), meta(Meta)]) :-
  279	setup_call_cleanup(
  280	    open(Path, read, In, [encoding(utf8)]),
  281	    read_string(In, _, Code),
  282	    close(In)),
  283	source_metadata(Path, Code, Meta),
  284	file_base_name(Path, File),
  285	file_name_extension(Title, Ext, File).
  286
  287%%	source_metadata(+Path, +Code, -Meta:dict) is det.
  288%
  289%	Obtain meta information about a local  source file. Defined meta
  290%	info is:
  291%
  292%	  - last_modified:Time
  293%	  Last modified stamp of the file.  Always present.
  294%	  - loaded:true
  295%	  Present of the file is a loaded source file
  296%	  - modified_since_loaded:true
  297%	  Present if the file loaded, has been edited, but not
  298%	  yet reloaded.
  299
  300source_metadata(Path, Code, Meta) :-
  301	findall(Name-Value, source_metadata(Path, Code, Name, Value), Pairs),
  302	dict_pairs(Meta, meta, Pairs).
  303
  304source_metadata(Path, _Code, path, Path).
  305source_metadata(Path, _Code, last_modified, Modified) :-
  306	time_file(Path, Modified).
  307source_metadata(Path, _Code, loaded, true) :-
  308	source_file(Path).
  309source_metadata(Path, _Code, modified_since_loaded, true) :-
  310	source_file_property(Path, modified(ModifiedWhenLoaded)),
  311	time_file(Path, Modified),
  312	ModifiedWhenLoaded \== Modified.
  313source_metadata(Path, _Code, module, Module) :-
  314	file_name_extension(_, Ext, Path),
  315	user:prolog_file_type(Ext, prolog),
  316	xref_public_list(Path, _, [module(Module)]).
  317
  318confirm_access(Path, Options) :-
  319	option(if(Condition), Options), !,
  320	must_be(oneof([loaded]), Condition),
  321	eval_condition(Condition, Path).
  322confirm_access(_, _).
  323
  324eval_condition(loaded, Path) :-
  325	source_file(Path).
  326
  327%%	swish_reply_resource(+Request) is semidet.
  328%
  329%	Serve /swish/Resource files. In recent   Bootstrap versions, the
  330%	path  to  `fonts/`   is   generated    that   should   refer  to
  331%	`node_modules/bootstrap/dist/fonts`. This could  be   a  bug  in
  332%	Bootstrap or in teh CSS cleaning. For   now,  we hack around the
  333%	issue here.
  334
  335swish_reply_resource(Request) :-
  336	option(path_info(Info), Request),
  337	resource_prefix(Prefix),
  338	sub_atom(Info, 0, _, _, Prefix), !,
  339	http_reply_file(swish_web(Info), [], Request).
  340swish_reply_resource(Request) :-	% see above
  341	option(path_info(Info), Request),
  342	sub_atom(Info, 0, _, _, 'fonts/'), !,
  343	atom_concat('node_modules/bootstrap/dist/', Info, Path),
  344	http_reply_file(swish_web(Path), [], Request).
  345
  346resource_prefix('css/').
  347resource_prefix('help/').
  348resource_prefix('form/').
  349resource_prefix('icons/').
  350resource_prefix('js/').
  351resource_prefix('node_modules/').
  352
  353%%	swish_page(+Options)//
  354%
  355%	Generate the entire SWISH default page.
  356
  357swish_page(Options) -->
  358	swish_navbar(Options),
  359	swish_content(Options).
  360
  361%%	swish_navbar(+Options)//
  362%
  363%	Generate the swish navigation bar.
  364
  365swish_navbar(Options) -->
  366	swish_resources,
  367	html(nav([ class([navbar, 'navbar-default']),
  368		   role(navigation)
  369		 ],
  370		 [ div(class('navbar-header'),
  371		       [ \collapsed_button,
  372			 \swish_logos(Options)
  373		       ]),
  374		   div([ class([collapse, 'navbar-collapse']),
  375			 id(navbar)
  376		       ],
  377		       [ ul([class([nav, 'navbar-nav', menubar])], []),
  378			 ul([class([nav, 'navbar-nav', 'navbar-right'])],
  379			    [ li(\notifications(Options)),
  380			      li(\search_box(Options)),
  381			      \li_login_button(Options),
  382			      li(\broadcast_bell(Options)),
  383			      li(\updates(Options))
  384			    ])
  385		       ])
  386		 ])).
  387
  388li_login_button(Options) -->
  389	swish_config:li_login_button(Options).
  390li_login_button(_Options) -->
  391	[].
  392
  393collapsed_button -->
  394	html(button([type(button),
  395		     class('navbar-toggle'),
  396		     'data-toggle'(collapse),
  397		     'data-target'('#navbar')
  398		    ],
  399		    [ span(class('sr-only'), 'Toggle navigation'),
  400		      span(class('icon-bar'), []),
  401		      span(class('icon-bar'), []),
  402		      span(class('icon-bar'), [])
  403		    ])).
  404
  405updates(_Options) -->
  406	html([ a(id('swish-updates'), []) ]).
  407
  408
  409		 /*******************************
  410		 *	      BRANDING		*
  411		 *******************************/
  412
  413%!	swish_title(+Options)// is det.
  414%
  415%	Emit the HTML header options dealing with the title and shortcut
  416%	icons.  This can be hooked using swish_config:title//1.
  417
  418swish_title(Options) -->
  419	swish_config:title(Options), !.
  420swish_title(_Options) -->
  421	html([ title('SWISH -- SWI-Prolog for SHaring'),
  422	       link([ rel('shortcut icon'),
  423		      href('/icons/favicon.ico')
  424		    ]),
  425	       link([ rel('apple-touch-icon'),
  426		      href('/icons/swish-touch-icon.png')
  427		    ])
  428	     ]).
  429
  430%!	swish_logos(+Options)// is det.
  431%
  432%	Emit the navbar branding logos at   the  top-left. Can be hooked
  433%	using swish_config:swish_logos//1.
  434
  435swish_logos(Options) -->
  436	swish_config:logo(Options), !.
  437swish_logos(Options) -->
  438	pengine_logo(Options),
  439	swish_logo(Options).
  440
  441%!	swish_config:logo(+Options)// is semidet.
  442%
  443%	Hook  to  include  the  top-left    logos.   The  default  calls
  444%	pengine_logo//1 and swish_logo//1.  The   implementation  should
  445%	emit     zero     or      more       <a>      elements.      See
  446%	`config_available/branding.pl` for an example.
  447
  448%!	pengine_logo(+Options)// is det.
  449%!	swish_logo(+Options)// is det.
  450%
  451%	Emit an <a> element that provides a   link to Pengines and SWISH
  452%	on this server. These may be called from swish_config:logo//1 to
  453%	include the default logos.
  454
  455pengine_logo(_Options) -->
  456	{ http_absolute_location(root(.), HREF, [])
  457	},
  458	html(a([href(HREF), class('pengine-logo')], &(nbsp))).
  459swish_logo(_Options) -->
  460	{ http_absolute_location(swish(.), HREF, [])
  461	},
  462	html(a([href(HREF), class('swish-logo')], &(nbsp))).
  463
  464
  465		 /*******************************
  466		 *	     CONTENT		*
  467		 *******************************/
  468
  469%%	swish_content(+Options)//
  470%
  471%	Generate the SWISH editor, Prolog output  area and query editor.
  472%	Options processed:
  473%
  474%	  - source(HREF)
  475%	  Load initial source from HREF
  476%	  - chat_count(Count)
  477%	  Indicate the presense of Count chat messages
  478
  479swish_content(Options) -->
  480	{ document_type(Type, Options)
  481	},
  482	swish_resources,
  483	swish_config_hash(Options),
  484	swish_options(Options),
  485	html(div([id(content), class([container, 'tile-top'])],
  486		 [ div([class([tile, horizontal]), 'data-split'('50%')],
  487		       [ div([ class([editors, tabbed])
  488			     ],
  489			     [ \source(Type, Options),
  490			       \notebooks(Type, Options)
  491			     ]),
  492			 div([class([tile, vertical]), 'data-split'('70%')],
  493			     [ div(class('prolog-runners'), []),
  494			       div(class('prolog-query'), \query(Options))
  495			     ])
  496		       ]),
  497		   \background(Options),
  498		   \examples(Options)
  499		 ])).
  500
  501
  502%%	swish_config_hash(+Options)//
  503%
  504%	Set `window.swish.config_hash` to a  hash   that  represents the
  505%	current configuration. This is used by   config.js  to cache the
  506%	configuration in the browser's local store.
  507
  508swish_config_hash(Options) -->
  509	{ swish_config_hash(Hash, Options) },
  510	js_script({|javascript(Hash)||
  511		   window.swish = window.swish||{};
  512		   window.swish.config_hash = Hash;
  513		   |}).
  514
  515
  516%!	swish_options(+Options)//
  517%
  518%	Emit additional options. This is  similar   to  config,  but the
  519%	config object is big and stable   for a particular SWISH server.
  520%	The options are set per session.
  521
  522swish_options(Options) -->
  523	js_script({|javascript||
  524		   window.swish = window.swish||{};
  525		   window.swish.option = window.swish.option||{};
  526		  |}),
  527	swish_options([show_beware, preserve_state], Options).
  528
  529swish_options([], _) --> [].
  530swish_options([H|T], Options) -->
  531	swish_option(H, Options),
  532	swish_options(T, Options).
  533
  534swish_option(Name, Options) -->
  535	{ Opt =.. [Name,Val],
  536	  option(Opt, Options),
  537	  JSVal = @(Val)
  538	}, !,
  539	js_script({|javascript(Name, JSVal)||
  540		   window.swish.option[Name] = JSVal;
  541		   |}).
  542swish_option(_, _) -->
  543	[].
  544
  545%%	source(+Type, +Options)//
  546%
  547%	Associate the source with the SWISH   page. The source itself is
  548%	stored  in  the  textarea  from  which  CodeMirror  is  created.
  549%	Options:
  550%
  551%	  - code(+String)
  552%	  Initial code of the source editor
  553%	  - file(+File)
  554%	  If present and code(String) is present, also associate the
  555%	  editor with the given file.  See storage.pl.
  556%	  - url(+URL)
  557%	  as file(File), but used if the data is loaded from an
  558%	  alias/file path.
  559%	  - title(+Title)
  560%	  Defines the title used for the tab.
  561
  562source(pl, Options) -->
  563	{ (   option(code(Spec), Options)
  564	  ;   option(download(browser), Options)
  565          ),
  566          !,
  567          download_source(Spec, Source, Options),
  568	  phrase(source_data_attrs(Options), Extra),
  569          option(label(Label), Options, 'Program')
  570	},
  571	html(div([ class(['prolog-editor']),
  572		   'data-label'(Label)
  573		 ],
  574		 [ textarea([ class([source,prolog]),
  575			      style('display:none')
  576			    | Extra
  577			    ],
  578			    Source)
  579		 ])).
  580source(_, _) --> [].
  581
  582source_data_attrs(Options) -->
  583	(source_file_data(Options) -> [] ; []),
  584	(source_url_data(Options) -> [] ; []),
  585	(source_download_data(Options) -> [] ; []),
  586	(source_title_data(Options) -> [] ; []),
  587	(source_meta_data(Options) -> [] ; []),
  588	(source_st_type_data(Options) -> [] ; []),
  589	(source_chat_data(Options) -> [] ; []).
  590
  591source_file_data(Options) -->
  592	{ option(file(File), Options) },
  593	['data-file'(File)].
  594source_url_data(Options) -->
  595	{ option(url(URL), Options) },
  596	['data-url'(URL)].
  597source_download_data(Options) -->
  598	{ option(download(Who), Options) },
  599	['data-download'(Who)].
  600source_title_data(Options) -->
  601	{ option(title(File), Options) },
  602	['data-title'(File)].
  603source_st_type_data(Options) -->
  604	{ option(st_type(Type), Options) },
  605	['data-st_type'(Type)].
  606source_meta_data(Options) -->
  607	{ option(meta(Meta), Options), !,
  608	  atom_json_dict(Text, Meta, [])
  609	},
  610	['data-meta'(Text)].
  611source_chat_data(Options) -->
  612	{ option(chat_count(Count), Options),
  613	  atom_json_term(JSON, _{count:Count}, [as(string)])
  614	},
  615	['data-chats'(JSON)].
  616
  617%%	background(+Options)//
  618%
  619%	Associate  the  background  program  (if  any).  The  background
  620%	program is not displayed in  the  editor,   but  is  sent to the
  621%	pengine for execution.
  622
  623background(Options) -->
  624	{ option(background(Spec), Options), !,
  625	  download_source(Spec, Source, Options)
  626	},
  627	html(textarea([ class([source,prolog,background]),
  628			style('display:none')
  629		      ],
  630		      Source)).
  631background(_) --> [].
  632
  633
  634examples(Options) -->
  635	{ option(examples(Examples), Options), !
  636	},
  637	html(textarea([ class([examples,prolog]),
  638			style('display:none')
  639		      ],
  640		      Examples)).
  641examples(_) --> [].
  642
  643
  644query(Options) -->
  645	{ option(q(Query), Options)
  646	}, !,
  647	html(textarea([ class([query,prolog]),
  648			style('display:none')
  649		      ],
  650		      Query)).
  651query(_) --> [].
  652
  653%%	notebooks(+Type, +Options)//
  654%
  655%	We have opened a notebook. Embed the notebook data in the
  656%	left-pane tab area.
  657
  658notebooks(swinb, Options) -->
  659	{ option(code(Spec), Options),
  660	  download_source(Spec, NoteBookText, Options),
  661	  phrase(source_data_attrs(Options), Extra)
  662	},
  663	html(div([ class('notebook'),
  664		   'data-label'('Notebook')		% Use file?
  665		 ],
  666		 [ pre([ class('notebook-data'),
  667			 style('display:none')
  668		       | Extra
  669		       ],
  670		       NoteBookText)
  671		 ])).
  672notebooks(_, _) --> [].
  673
  674%%	download_source(+HREF, -Source, +Options) is det.
  675%
  676%	Download source from a URL.  Options processed:
  677%
  678%	  - timeout(+Seconds)
  679%	    Max time to wait for reading the source.  Default
  680%	    is 10 seconds.
  681%	  - max_length(+Chars)
  682%	    Maximum lenght of the content.  Default is 1 million.
  683%	  - encoding(+Encoding)
  684%	    Encoding used to interpret the text.  Default is UTF-8.
  685%
  686%	@bug: Should try to interpret the encoding from the HTTP
  687%	      header.
  688
  689download_source(_HREF, Source, Options) :-
  690	option(download(browser), Options),
  691	!,
  692        Source = "".
  693download_source(HREF, Source, Options) :-
  694	uri_is_global(HREF), !,
  695	download_href(HREF, Source, Options).
  696download_source(Source0, Source, Options) :-
  697	option(max_length(MaxLen), Options, 1_000_000),
  698	string_length(Source0, Len),
  699	(   Len =< MaxLen
  700	->  Source = Source0
  701	;   format(string(Source),
  702		   '% ERROR: Content too long (max ~D)~n', [MaxLen])
  703	).
  704
  705download_href(HREF, Source, Options) :-
  706	option(timeout(TMO), Options, 10),
  707	option(max_length(MaxLen), Options, 1_000_000),
  708	catch(call_with_time_limit(
  709		  TMO,
  710		  setup_call_cleanup(
  711		      http_open(HREF, In,
  712				[ cert_verify_hook(cert_accept_any)
  713				]),
  714		      read_source(In, MaxLen, Source, Options),
  715		      close(In))),
  716	      E, load_error(E, Source)).
  717
  718read_source(In, MaxLen, Source, Options) :-
  719	option(encoding(Enc), Options, utf8),
  720	set_stream(In, encoding(Enc)),
  721	ReadMax is MaxLen + 1,
  722	read_string(In, ReadMax, Source0),
  723	string_length(Source0, Len),
  724	(   Len =< MaxLen
  725	->  Source = Source0
  726	;   format(string(Source),
  727		   ' % ERROR: Content too long (max ~D)~n', [MaxLen])
  728	).
  729
  730load_error(E, Source) :-
  731	message_to_string(E, String),
  732	format(string(Source), '% ERROR: ~s~n', [String]).
  733
  734%%	document_type(-Type, +Options) is det.
  735%
  736%	Determine the type of document.
  737%
  738%	@arg Type is one of `swinb` or `pl`
  739
  740document_type(Type, Options) :-
  741	(   option(type(Type0), Options)
  742	->  Type = Type0
  743	;   option(meta(Meta), Options),
  744	    file_name_extension(_, Type0, Meta.name),
  745	    Type0 \== ''
  746	->  Type = Type0
  747	;   option(st_type(external), Options),
  748	    option(url(URL), Options),
  749	    file_name_extension(_, Ext, URL),
  750	    ext_type(Ext, Type)
  751	->  true
  752	;   Type = pl
  753	).
  754
  755ext_type(swinb, swinb).
  756
  757
  758		 /*******************************
  759		 *	     RESOURCES		*
  760		 *******************************/
  761
  762%%	swish_resources//
  763%
  764%	Include  SWISH  CSS  and   JavaScript.    This   does   not  use
  765%	html_require//1  because  we  need  to   include  the  JS  using
  766%	RequireJS, which requires a non-standard script element.
  767
  768swish_resources -->
  769	swish_css,
  770	swish_js.
  771
  772swish_js  --> html_post(head, \include_swish_js).
  773swish_css --> html_post(head, \include_swish_css).
  774
  775include_swish_js -->
  776	{ swish_resource(js, JS),
  777	  swish_resource(rjs, RJS),
  778	  http_absolute_location(swish(js/JS), SwishJS, []),
  779	  http_absolute_location(swish(RJS),   SwishRJS, [])
  780	},
  781	rjs_timeout(JS),
  782	html(script([ src(SwishRJS),
  783		      'data-main'(SwishJS)
  784		    ], [])).
  785
  786rjs_timeout('swish-min') --> !,
  787	js_script({|javascript||
  788// Override RequireJS timeout, until main file is loaded.
  789window.require = { waitSeconds: 0 };
  790		  |}).
  791rjs_timeout(_) --> [].
  792
  793
  794include_swish_css -->
  795	{ swish_resource(css, CSS),
  796	  http_absolute_location(swish(css/CSS), SwishCSS, [])
  797	},
  798	html(link([ rel(stylesheet),
  799		    href(SwishCSS)
  800		  ])).
  801
  802swish_resource(Type, ID) :-
  803	alt(Type, ID, File),
  804	(   File == (-)
  805	;   absolute_file_name(File, _P, [file_errors(fail), access(read)])
  806	), !.
  807
  808alt(js,  'swish-min',     swish_web('js/swish-min.js')) :-
  809	\+ debugging(nominified).
  810alt(js,  'swish',         swish_web('js/swish.js')).
  811alt(css, 'swish-min.css', swish_web('css/swish-min.css')) :-
  812	\+ debugging(nominified).
  813alt(css, 'swish.css',     swish_web('css/swish.css')).
  814alt(rjs, 'js/require.js', swish_web('js/require.js')) :-
  815	\+ debugging(nominified).
  816alt(rjs, 'node_modules/requirejs/require.js', -).
  817
  818
  819		 /*******************************
  820		 *	       REST		*
  821		 *******************************/
  822
  823%%	swish_rest_reply(+Method, +Request, +Options) is det.
  824%
  825%	Handle non-GET requests.  Such requests may be used to modify
  826%	source code.
  827
  828swish_rest_reply(put, Request, Options) :-
  829	merge_options(Options, [alias(_)], Options1),
  830	source_file(Request, File, Options1), !,
  831	option(content_type(String), Request),
  832	http_parse_header_value(content_type, String, Type),
  833	read_data(Type, Request, Data, Meta),
  834	authorized(file(update(File,Meta)), Options1),
  835	setup_call_cleanup(
  836	    open(File, write, Out, [encoding(utf8)]),
  837	    format(Out, '~s', [Data]),
  838	    close(Out)),
  839	reply_json_dict(true).
  840
  841read_data(media(Type,_), Request, Data, Meta) :-
  842	http_json:json_type(Type), !,
  843	http_read_json_dict(Request, Dict),
  844	del_dict(data, Dict, Data, Meta).
  845read_data(media(text/_,_), Request, Data, _{}) :-
  846	http_read_data(Request, Data,
  847		       [ to(string),
  848			 input_encoding(utf8)
  849		       ])