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/* Part of XPCE --- The SWI-Prolog GUI toolkit
Author: Jan Wielemaker and Anjo Anjewierden
E-mail: jan@swi.psy.uva.nl
WWW: http://www.swi.psy.uva.nl/projects/xpce/
Copyright (c) 2000-2013, University of Amsterdam
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(html_form, []).
:- use_module(library(pce)).
:- use_module(library(url)).
:- use_module(doc(emit)).
:- use_module(doc(util)).
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Define the classes required to realise HTML forms. Note that a form
itself is *not* a parbox object (and device). This would seem logical,
but makes it extremely difficult to make it completely `absent' with
regard to layout, for example of the form is inside a <center> it should
center its content.
For these reasons, a form is just an abstract object, related to its
controls and enclosing pbox using hyper-links.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
:- pce_begin_class(html_form, object,
"Represent an HTML form").
variable(method, {get,post}, both, "Submission method").
variable(action, name, both, "Script URL").
variable(hidden, sheet*, get, "Hidden fields").
variable(enctype, name := 'application/x-www-form-urlencoded',
both, "Field-encoding used").
initialise(F, Attrs:prolog, PB:parbox) :->
"Create from HTML attributes"::
send_super(F, initialise),
new(_, hyper(PB, F, form, parbox)),
apply_options(Attrs, form_option, F).
form_option(_,_) :- fail.
hidden_input(F, Name:name, Value:name) :->
"Attach a hidden input-field to the form"::
( get(F, hidden, Sheet),
Sheet \== @nil
-> true
; send(F, slot, hidden, new(Sheet, sheet))
),
send(Sheet, value, Name, Value).
submit(F) :->
"Submit the form"::
get(F, form_data, Sheet),
( get(F, method, get)
-> get(F, action, Action),
new(S, string),
send(Sheet, for_all,
message(@prolog, add_field, S, @arg1?name, @arg1?value)),
send(S, prepend, Action),
get(F, hypered, parbox, PB),
send(PB?window, goto_url, S) % @browser
; send(@display, inform, 'No support for POST forms yet')
).
add_field(String, Name, Value) :-
www_form_encode(Name, CodedName),
www_form_encode(Value, CodeValue),
( get(String, size, 0)
-> Fmt = '?%s=%s'
; Fmt = '&%s=%s'
),
send(String, append, string(Fmt, [CodedName, CodeValue])).
form_data(F, Data:sheet) :<-
"Get data from the form as a sheet"::
( get(F, hidden, Hidden),
Hidden \== @nil
-> get(Hidden, clone, Data)
; new(Data, sheet)
),
send(F, send_hyper, control, fill_form, Data).
append(F, Control:object) :->
"Associate a control to this form"::
new(_, hyper(F, Control, control, form)).
:- pce_end_class.
:- pce_begin_class(html_text_input, text_item,
"HTML Input field").
initialise(I, Attributes:prolog) :->
send_super(I, initialise, input),
send(I, show_label, @off),
apply_options(Attributes, input_option, I).
input_option(type(_), _).
input_option(size(W), I) :-
send(I, length, W).
input_option(value(V), I) :-
send(I, selection, V).
fill_form(I, Data:sheet) :->
"Add my contribution to the form"::
send(Data, value, I?name, I?selection).
:- pce_end_class.
:- pce_begin_class(html_submit_input, button,
"Submit the form").
initialise(B, Attrs:prolog) :->
"Create from HTML attributes"::
send_super(B, initialise, submit, message(@receiver, submit)),
apply_options(Attrs, submit_options, B).
submit_options(value(Name), B) :-
send(B, selection, Name).
submit_options(type(_), _).
fill_form(_B, _Data:sheet) :->
"Nothing to do for buttons"::
true.
submit(B) :->
"Find form and submit it"::
( get(B, hypered, form, Form)
-> send(Form, submit)
; send(B, error, no_form)
).
:- pce_end_class.
/*******************************
* <SELECT> *
*******************************/
:- pce_begin_class(html_select_menu, menu, "<select> without size").
initialise(S, Name:name, Attr:prolog, Content:prolog) :->
send_super(S, initialise, Name, cycle),
send(S, show_label, @off),
select_content(Content, S),
apply_options(Attr, select_menu_option, S).
select_menu_option(_, _).
fill_form(I, Data:sheet) :->
"Add my contribution to the form"::
send(Data, value, I?name, I?selection).
select_content([], _).
select_content([element(option, Attr, Content)|T], Menu) :-
content_to_atom(Content, Atom),
get(Atom, strip, canonicalise, Clean),
( option(value(Value), Attr)
-> true
; Value = Clean
),
send(Menu, append, new(MI, menu_item(Value, @default, Clean))),
( option(selected, Attr)
-> send(Menu, selection, MI)
; true
),
select_content(T, Menu).
:- pce_end_class.
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