tailbone/tailbone/subscribers.py

# -*- coding: utf-8; -*-
################################################################################
#
#  Rattail -- Retail Software Framework
#  Copyright © 2010-2022 Lance Edgar
#
#  This file is part of Rattail.
#
#  Rattail 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 3 of the License, or (at your option) any later
#  version.
#
#  Rattail 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
#  Rattail.  If not, see <http://www.gnu.org/licenses/>.
#
################################################################################
"""
Event Subscribers
"""

from __future__ import unicode_literals, absolute_import

import six
import json
import datetime

import rattail
from rattail.db import model

import colander
import deform
from pyramid import threadlocal
from webhelpers2.html import tags

import tailbone
from tailbone import helpers
from tailbone.db import Session
from tailbone.config import csrf_header_name
from tailbone.menus import make_simple_menus
from tailbone.util import should_use_buefy


def new_request(event):
    """
    Identify the current user, and cache their current permissions.  Also adds
    the ``rattail_config`` attribute to the request.

    A global Rattail ``config`` should already be present within the Pyramid
    application registry's settings, which would normally be accessed via::
    
       request.registry.settings['rattail_config']

    This function merely "promotes" that config object so that it is more
    directly accessible, a la::

       request.rattail_config

    .. note::
       This of course assumes that a Rattail ``config`` object *has* in fact
       already been placed in the application registry settings.  If this is
       not the case, this function will do nothing.
    """
    request = event.request
    rattail_config = request.registry.settings.get('rattail_config')
    # TODO: why would this ever be null?
    if rattail_config:
        request.rattail_config = rattail_config

    request.user = None
    uuid = request.authenticated_userid
    if uuid:
        request.user = Session.query(model.User).get(uuid)
        if request.user:
            # assign user to the session, for sake of versioning
            Session().set_continuum_user(request.user)

    # assign client IP address to the session, for sake of versioning
    Session().continuum_remote_addr = request.client_addr

    request.is_admin = bool(request.user) and request.user.is_admin()
    request.is_root = request.is_admin and request.session.get('is_root', False)

    if rattail_config:
        app = rattail_config.get_app()
        auth = app.get_auth_handler()
        request.tailbone_cached_permissions = auth.get_permissions(
            Session(), request.user)


def before_render(event):
    """
    Adds goodies to the global template renderer context.
    """

    request = event.get('request') or threadlocal.get_current_request()

    renderer_globals = event
    renderer_globals['rattail_app'] = request.rattail_config.get_app()
    renderer_globals['h'] = helpers
    renderer_globals['url'] = request.route_url
    renderer_globals['rattail'] = rattail
    renderer_globals['tailbone'] = tailbone
    renderer_globals['model'] = request.rattail_config.get_model()
    renderer_globals['enum'] = request.rattail_config.get_enum()
    renderer_globals['six'] = six
    renderer_globals['json'] = json
    renderer_globals['datetime'] = datetime
    renderer_globals['colander'] = colander
    renderer_globals['deform'] = deform
    renderer_globals['csrf_header_name'] = csrf_header_name(request.rattail_config)

    # theme  - we only want do this for classic web app, *not* API
    # TODO: so, clearly we need a better way to distinguish the two
    if 'tailbone.theme' in request.registry.settings:
        renderer_globals['theme'] = request.registry.settings['tailbone.theme']
        # note, this is just a global flag; user still needs permission to see picker
        expose_picker = request.rattail_config.getbool('tailbone', 'themes.expose_picker',
                                                       default=False)
        renderer_globals['expose_theme_picker'] = expose_picker
        if expose_picker:
            # tailbone's config extension provides a default theme selection,
            # so the default we specify here *probably* should not matter
            available = request.rattail_config.getlist('tailbone', 'themes',
                                                       default=['falafel'])
            if 'default' not in available:
                available.insert(0, 'default')
            options = [tags.Option(theme) for theme in available]
            renderer_globals['theme_picker_options'] = options

        # heck while we're assuming the classic web app here...
        # (we don't want this to happen for the API either!)
        # TODO: just..awful *shrug*
        # note that we assume "simple" menus nowadays
        if request.rattail_config.getbool('tailbone', 'menus.simple', default=True):
            renderer_globals['menus'] = make_simple_menus(request)

        # TODO: ugh, same deal here
        renderer_globals['messaging_enabled'] = request.rattail_config.getbool(
            'tailbone', 'messaging.enabled', default=False)

        # background color may be set per-request, by some apps
        if hasattr(request, 'background_color') and request.background_color:
            renderer_globals['background_color'] = request.background_color
        else: # otherwise we use the one from config
            renderer_globals['background_color'] = request.rattail_config.get(
                'tailbone', 'background_color')

        # buefy themes get some extra treatment
        if should_use_buefy(request):

            # declare vue.js and buefy versions to use.  the default
            # values here are "quite conservative" as of this writing,
            # perhaps too much so, but at least they should work fine.
            renderer_globals['vue_version'] = request.rattail_config.get(
                'tailbone', 'vue_version') or '2.6.10'
            renderer_globals['buefy_version'] = request.rattail_config.get(
                'tailbone', 'buefy_version') or '0.8.6'

            # maybe set custom stylesheet
            css = None
            if request.user:
                css = request.rattail_config.get('tailbone.{}'.format(request.user.uuid),
                                                 'buefy_css')
            if not css:
                css = request.rattail_config.get('tailbone', 'theme.falafel.buefy_css')
            renderer_globals['buefy_css'] = css

        # here we globally declare widths for grid filter pseudo-columns
        widths = request.rattail_config.get('tailbone', 'grids.filters.column_widths')
        if widths:
            widths = widths.split(';')
            if len(widths) < 2:
                widths = None
        if not widths:
            widths = ['15em', '15em']
        renderer_globals['filter_fieldname_width'] = widths[0]
        renderer_globals['filter_verb_width'] = widths[1]


def add_inbox_count(event):
    """
    Adds the current user's inbox message count to the global renderer context.

    Note that this is not enabled by default; to turn it on you must do this:

       config.add_subscriber('tailbone.subscribers.add_inbox_count', 'pyramid.events.BeforeRender')
    """
    request = event.get('request') or threadlocal.get_current_request()
    if request.user:
        renderer_globals = event
        enum = request.rattail_config.get_enum()
        renderer_globals['inbox_count'] = Session.query(model.Message)\
                                                 .outerjoin(model.MessageRecipient)\
                                                 .filter(model.MessageRecipient.recipient == Session.merge(request.user))\
                                                 .filter(model.MessageRecipient.status == enum.MESSAGE_STATUS_INBOX)\
                                                 .count()


def context_found(event):
    """
    Attach some goodies to the request object.

    The following is attached to the request:

    * The currently logged-in user instance (if any), as ``user``.

    * ``is_admin`` flag indicating whether user has the Administrator role.

    * ``is_root`` flag indicating whether user is currently elevated to root.

    * A shortcut method for permission checking, as ``has_perm()``.

    * A shortcut method for fetching the referrer, as ``get_referrer()``.
    """

    request = event.request

    def has_perm(name):
        if name in request.tailbone_cached_permissions:
            return True
        return request.is_root
    request.has_perm = has_perm

    def has_any_perm(*names):
        for name in names:
            if has_perm(name):
                return True
        return False
    request.has_any_perm = has_any_perm

    def get_referrer(default=None, **kwargs):
        if request.params.get('referrer'):
            return request.params['referrer']
        if request.session.get('referrer'):
            return request.session.pop('referrer')
        referrer = request.referrer
        if (not referrer or referrer == request.current_route_url()
            or not referrer.startswith(request.host_url)):
            if default:
                referrer = default
            else:
                referrer = request.route_url('home')
        return referrer
    request.get_referrer = get_referrer

    def get_session_timeout():
        """
        Returns the timeout in effect for the current session
        """
        return request.session.get('_timeout')
    request.get_session_timeout = get_session_timeout


def includeme(config):
    config.add_subscriber(new_request, 'pyramid.events.NewRequest')
    config.add_subscriber(before_render, 'pyramid.events.BeforeRender')
    config.add_subscriber(context_found, 'pyramid.events.ContextFound')