/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@cs.vu.nl WWW: http://www.swi-prolog.org Copyright (C): 2013, VU University Amsterdam This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA As a special exception, if you link this library with other files, compiled with a Free Software compiler, to produce an executable, this library does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. */ :- module(http_ax, [ http_ax_attributes/2, % +Spec, -AttributeList ax_form_attributes/2 % +Form, -Values ]). :- use_module(library(error)). /** Attribute Exchange library This library can be used to create HTTP request parameters and analyse form-data for _attribute exchange_. Attribute exchange (AX) is used by OpenID and OAuth to fetch attributes for accounts, such as the real username or e-mail address. */ %% http_ax_attributes(+Spec, -HTTPAttributes) is det. % % True when HTTPAttributes is a list of Name=Value pairs that can % be used with an HTTP request to query for the attributes Spec. % Spec is a list of elements =|Alias(Value[, Options])|=. Options % include: % % - required % The attribute is required. This is mutually exclusive % with =if_available=. % - if_available % Only provide the attribute if it is available. This is % mutually exclusive with =required=. This is the default. % - url(+URL) % Can be used to ovcerrule or extend the ax_alias/2. % - count(+Count) % Maximum number of values to provide % % For example: % % == % ?- http_ax_attributes([ nickname(Nick), % email(Email, [required]) % ], Params). % Params = [ 'openid.ax.mode' = fetch_request, % 'openid.ax.type.nickname' = 'http://axschema.org/namePerson/friendly', % 'openid.ax.type.email' = 'http://axschema.org/contact/email', % 'openid.ax.required' = email, % 'openid.ax.if_available' = nickname % ]. % == http_ax_attributes(Spec, [ 'openid.ns.ax' = 'http://openid.net/srv/ax/1.0', 'openid.ax.mode' = fetch_request | AllAttr ]) :- maplist(type_alias, Spec, AliasAttrs), partition(required, Spec, Required, Optional), alias_list(Required, 'openid.ax.required', RequiredAttr), alias_list(Optional, 'openid.ax.if_available', IfAvailableAttr), count_attr(Spec, CountAttr), append([AliasAttrs, RequiredAttr, IfAvailableAttr, CountAttr], AllAttr). type_alias(Spec, Attr=URL) :- functor(Spec, Alias, Arity), ( Arity > 1, arg(2, Spec, Options), memberchk(url(URL), Options) -> true ; ax_alias(Alias, URL) -> true ; existence_error(ax_alias, Alias) ), atom_concat('openid.ax.type.', Alias, Attr). required(Spec) :- functor(Spec, _, 2), arg(2, Spec, Options), memberchk(required, Options). alias_list([], _, []). alias_list(Specs, A, [A=V]) :- maplist(alias_name, Specs, Aliases), atomic_list_concat(Aliases, ',', V). alias_name(Spec, Alias) :- functor(Spec, Alias, _). count_attr([], []). count_attr([Spec|T0], [A=Count|T]) :- functor(Spec, Alias, 2), arg(2, Spec, Options), memberchk(count(Count), Options), !, atomic_list_concat('openid.ax.count.', Alias, A), count_attr(T0, T). count_attr([_|T0], T) :- count_attr(T0, T). %% ax_alias(?Alias, ?URL) is nondet. % % True when Alias is an alias name for the AX schema URL. This % predicate is defined as _multifile_. % % Note that Google federated login only supports =email=, % =country=, =language=, =firstname= and =lastname=. :- multifile ax_alias/2. ax_alias(nickname, 'http://axschema.org/namePerson/friendly'). ax_alias(email, 'http://axschema.org/contact/email'). ax_alias(fullname, 'http://axschema.org/namePerson'). ax_alias(dob, 'http://axschema.org/birthDate'). ax_alias(gender, 'http://axschema.org/person/gender'). ax_alias(postcode, 'http://axschema.org/contact/postalCode/home'). ax_alias(country, 'http://axschema.org/contact/country/home'). ax_alias(language, 'http://axschema.org/pref/language'). ax_alias(timezone, 'http://axschema.org/pref/timezone'). ax_alias(prefix, 'http://axschema.org/namePerson/prefix'). ax_alias(firstname, 'http://axschema.org/namePerson/first'). ax_alias(lastname, 'http://axschema.org/namePerson/last'). ax_alias(suffix, 'http://axschema.org/namePerson/suffix'). /******************************* * RESPONSE * *******************************/ %% ax_form_attributes(+Form, -Values) is det. % % True if Values is a list Alias(Value) for each exchanged % attribute. % % Note that we assume we get the same alias names as we used for % requesting the data. Not sure whether this is true. % % @arg Form is an HTTP form as returned using the form(Form) % option of http_parameters/3. ax_form_attributes(Form, Values) :- ( memberchk('openid.ax.mode'=fetch_response, Form) -> Ext = ax ; memberchk(ExtNS='http://openid.net/srv/ax/1.0', Form), atomic_list_concat([openid,ns,Ext], '.', ExtNS) -> true ), ax_attributes(Form, Ext, Values). ax_form_attributes(_, []). ax_attributes([], _, []). ax_attributes([Name=Value|T0], Ext, AXs) :- atomic_list_concat([openid, Ext, value, Alias|_Num], '.', Name), !, AX =.. [Alias,Value], AXs = [AX|AXT], ax_attributes(T0, Ext, AXT). ax_attributes([_|T0], Ext, AXs) :- ax_attributes(T0, Ext, AXs).