:- package(servlet).
servlet_init(Servlet) :-
info(servlet_init(Servlet)).
servlet_destroy(Servlet) :-
info(servlet_destroy(Servlet)).
servlet_post(Servlet, Request, Response) :- % called on "POST"
info(servlet_post(Servlet, Request, Response)),
minserve(Servlet, Request, Response).
servlet_get(Servlet, Request, Response) :- % called on "GET"
info(servlet_get(Servlet, Request, Response)),
minserve(Servlet, Request, Response).
minserve(Servlet, Request, Response) :-
info(minserve(Servlet, Request, Response)),
request_get_parameter_values(Request,'radio1',[Type|_]),
info(request_get_parameter_values(Request,'Type',[Type|_])),
'_init_stream'(Type,Response,Stream),
info('init_stream'(Type,Response,Stream)),
'_collect_parameters'(Request,Parameterss),
info('collect_parameters'(Request,Parameterss)),
'_write_parameters'(Type,Parameterss, Stream),
info('write_parameters'(Type,Parameterss, Stream)),
info('done').
% info(+Term) - log something to server log
info(Term) :-
writeq(Term),nl,flush_output.
'_collect_parameters'(Request,Parameterss) :-
request_get_parameter_names(Request,Names),
findall(name_values(Name,ValuesOfName),
(
member(Name,Names),
request_get_parameter_values(Request,Name,ValuesOfName)
),
Parameterss).
%'_write_parameters'(+Mimetype, +Parameterss, +Stream)
'_write_parameters'(text, Parameterss,Stream) :-
writeq(Stream,Parameterss),nl(Stream),flush_output(Stream).
'_write_parameters'(html, Parameterss, Stream) :-
write(Stream,''),nl(Stream),
write(Stream,'output in html format'),nl(Stream),
write(Stream,''),nl(Stream),
write(Stream,''),nl(Stream),
write(Stream,''),nl(Stream),
once( ( member(Parameters,Parameterss),
writeq(Stream,Parameters),nl(Stream),
fail
;
true
)),
write(Stream,'
'),nl(Stream),
write(Stream,''),nl(Stream),
write(Stream,''),nl(Stream),flush_output(Stream).
'_write_parameters'(xml, Parameterss,Stream) :-
namevalues_xml(Parameterss,XMLterm),
info(write_xml(XMLterm)),
write_xml(Stream,XMLterm),flush_output(Stream).
% convert Parameter lists to/from XML term.
namevalues_xml(NameValues,document([xml([version = '1.0'])],element(data,[],Elements),[])):-
'_nvs_elements'(NameValues,Elements).
'_nvs_elements'([],[]).
'_nvs_elements'([NameValue|NameValues],[Element|Elements]):-
'_nvs_element'(NameValue,Element),
'_nvs_elements'(NameValues,Elements).
'_nvs_element'(name_values(Name,Values),element(name_values,[],[element(name,[],[chardata(Name)])|ValueElements])):-
'_value_elements'(Values,ValueElements).
'_value_elements'([],[]).
'_value_elements'([Value|Values],[ValueElement|ValueElements]):-
'_value_element'(Value,ValueElement),
'_value_elements'(Values,ValueElements).
'_value_element'(Value,element(value,[],[chardata(Value)])).
% set the right MIME type for each format.
'_init_stream'(html,Response, Stream) :-
response_set_content_type(Response, 'text/html'),
response_get_writer(Response, Stream).
'_init_stream'(text,Response, Stream) :-
response_set_content_type(Response, 'text/plain'),
response_get_writer(Response, Stream).
'_init_stream'(xml,Response, Stream) :-
response_set_content_type(Response, 'text/xml'),
response_get_writer(Response, Stream).