/* 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
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. /******************************* * 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.