1/*  Part of ClioPatria SeRQL and SPARQL server
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@cs.vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (C): 2010 VU University Amsterdam
    7
    8    This program is free software; you can redistribute it and/or
    9    modify it under the terms of the GNU General Public License
   10    as published by the Free Software Foundation; either version 2
   11    of the License, or (at your option) any later version.
   12
   13    This program is distributed in the hope that it will be useful,
   14    but WITHOUT ANY WARRANTY; without even the implied warranty of
   15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   16    GNU General Public License for more details.
   17
   18    You should have received a copy of the GNU General Public
   19    License along with this library; if not, write to the Free Software
   20    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   21
   22    As a special exception, if you link this library with other files,
   23    compiled with a Free Software compiler, to produce an executable, this
   24    library does not by itself cause the resulting executable to be covered
   25    by the GNU General Public License. This exception does not however
   26    invalidate any other reasons why the executable file might be covered by
   27    the GNU General Public License.
   28*/
   29
   30:- module(html_basics,
   31	  [ hidden//2,			% +Name, +Value
   32	    form_input//2,		% +Label, +Input
   33	    form_submit//1,		% +Label
   34	    n//2,			% +Format, +Value
   35	    nc//2,			% +Format, +Value
   36	    nc//3,			% +Format, +Value, +Options
   37	    odd_even_row//3,		% +Row, -Next, :Content
   38	    sort_th//3,			% +Field, +ByNow, :Content
   39	    insert_html_file//1		% +FileSpec
   40	  ]).   41:- use_module(library(http/html_write)).   42:- use_module(library(sgml)).   43:- use_module(library(lists)).   44:- use_module(library(option)).   45:- use_module(library(occurs)).   46:- use_module(library(http/http_dispatch)).   47:- use_module(library(http/http_wrapper)).   48
   49:- html_meta((
   50	form_input(html, html, ?, ?),
   51	odd_even_row(+, -, html, ?, ?),
   52	sort_th(+, +, html, ?, ?))).

   57		 /*******************************
   58		 *	       FORMS		*
   59		 *******************************/

 hidden(+Name, +Value)// is det

Create a hidden input field with given name and value

   65hidden(Name, Value) -->
   66	html(input([ type(hidden),
   67		     name(Name),
   68		     value(Value)
   69		   ])).

 form_input(+Label, +Input)// is det

 form_submit(+Label)// is det

Building blocks for HTML forms. The form itself is a two-column table of class form with labels at the left and inputs at the right. These rules create rows for input and submit.

   79form_input(Label, Input) -->
   80	html(tr([ th(class(label), Label),
   81		  td(Input)
   82		])).
   83
   84
   85form_submit(Label) -->
   86	html(tr(class(buttons),
   87		[ th([align(right), colspan(2)],
   88		     input([ type(submit),
   89			     value(Label)
   90			   ]))
   91		])).
   92
   93
   94		 /*******************************
   95		 *	       TABLES		*
   96		 *******************************/

 nc(+Format, +Value)// is det

 nc(+Format, +Value, +Options)// is det

Numeric cell. The value is formatted using Format and right-aligned in a table cell (td).

Arguments:

Format	- is a (numeric) format as described by format/2 or the constant human. Human formatting applies to integers and prints then in abreviated (K,M,T) form, e.g., 4.5M for 4.5 million.
Options	- is passed as attributed to the td element. Default alignment is right.

  111nc(Fmt, Value) -->
  112	nc(Fmt, Value, []).
  113
  114nc(Fmt, Value, Options) -->
  115	{ class(Value, Class),
  116	  merge_options(Options,
  117			[ align(right),
  118			  class(Class)
  119			], Opts),
  120	  number_html(Fmt, Value, HTML)
  121	},
  122	html(td(Opts, HTML)).
  123
  124class(Value, Class) :-
  125	(   integer(Value)
  126	->  Class = int
  127	;   float(Value)
  128	->  Class = float
  129	;   Class = value
  130	).

 odd_even_row(+Row, -Next, :Content)//

Create odd/even alternating table rows from a DCG.

  137odd_even_row(Row, Next, Content) -->
  138	{ (   Row mod 2 =:= 0
  139	  ->  Class = even
  140	  ;   Class = odd
  141	  ),
  142	  Next is Row+1
  143	},
  144	html(tr(class(Class), Content)).

 sort_th(+Field, +ByNow, :Label)

Provide a column-header for a table that can be resorted. This call creates a th element holding an a. The a has either CSS class sorted if the column is sorted or resort if the column can be sorted on this column. The use of this component demands that the handler processes the parameter sort_by using the field-name as argument.

Arguments:

Field	- is the field-name that describes the sort on this column.
ByNow	- is the field on which the table is currently sorted.
Label	- is the label of the a element

  161sort_th(Name, Name, Label) -->
  162	html(th(a([class(sorted)], Label))).
  163sort_th(Name, _By, Label) -->
  164	{ http_current_request(Request),
  165	  http_reload_with_parameters(Request, [sort_by(Name)], HREF)
  166	},
  167	html(th(a([href(HREF), class(resort)], Label))).
  168
  169
  170		 /*******************************
  171		 *	       NUMBERS		*
  172		 *******************************/

 n(+Format, +Value)//

HTML component to emit a number.

See also

- nc//2 for details.

  180n(Fmt, Value) -->
  181	{ number_html(Fmt, Value, HTML) },
  182	html(HTML).
  183
  184number_html(human, Value, HTML) :-
  185	integer(Value), !,
  186	human_count(Value, HTML).
  187number_html(Fmt, Value, HTML) :-
  188	number(Value), !,
  189	HTML = Fmt-[Value].
  190number_html(_, Value, '~p'-[Value]).
  191
  192
  193human_count(Number, HTML) :-
  194	Number < 1024, !,
  195	HTML = '~d'-[Number].
  196human_count(Number, HTML) :-
  197	Number < 1024*1024, !,
  198	KB is Number/1024,
  199	digits(KB, N),
  200	HTML = '~*fK'-[N, KB].
  201human_count(Number, HTML) :-
  202	Number < 1024*1024*1024, !,
  203	MB is Number/(1024*1024),
  204	digits(MB, N),
  205	HTML = '~*fM'-[N, MB].
  206human_count(Number, HTML) :-
  207	TB is Number/(1024*1024*1024),
  208	digits(TB, N),
  209	HTML = '~*fG'-[N, TB].
  210
  211digits(Count, N) :-
  212	(   Count < 100
  213	->  N = 1
  214	;   N = 0
  215	).
  216
  217
  218		 /*******************************
  219		 *	   INCLUDE FILES	*
  220		 *******************************/

 insert_html_file(+Specification)//

Insert the content of an HTML file into the current document. Only the content of the body element is included.

  227insert_html_file(Alias) -->
  228	{ absolute_file_name(Alias, Page, [access(read)]),
  229	  load_html_file(Page, DOM),
  230	  contains_term(element(body, _, Body), DOM),
  231	  Style = element(style, _, _),
  232	  findall(Style, sub_term(Style, DOM), Styles),
  233	  append(Styles, Body, Content)
  234	},
  235	html(Content)