~launchpad-pqm/launchpad/devel

# Copyright 2010 Canonical Ltd.  This software is licensed under the

# GNU Affero General Public License version 3 (see the file LICENSE).

"""Manage a Timeline for a request."""

__all__ = [

    'get_request_timeline',

    'set_request_timeline',

    ]

__metaclass__ = type

# XXX RobertCollins 2010-09-01 bug=623199: Undesirable but pragmatic.

# Because of this bug, rather than using request.annotations we have

# to work in with the webapp.adapter request model, which is 

# different to that used by get_current_browser_request.

from canonical.launchpad import webapp

from timeline import Timeline

def get_request_timeline(request):

    """Get a `Timeline` for request.

    This should ideally return the request.annotations['timeline'], creating it

    if necessary. However due to bug 623199 it instead using the adapter

    context for 'requests'. Once bug 623199 is fixed it will instead use the

    request annotations.

    :param request: A zope/launchpad request object.

    :return: A lp.services.timeline.timeline.Timeline object for the request.

    """

    try:

        return webapp.adapter._local.request_timeline

    except AttributeError:

        return set_request_timeline(request, Timeline())

    # Disabled code path: bug 623199, ideally we would use this code path.

    return request.annotations.setdefault('timeline', Timeline())

def set_request_timeline(request, timeline):

    """Explicitly set a timeline for request.

    This is used by code which wants to manually assemble a timeline.

    :param request: A zope/launchpad request object.

    :param timeline: A Timeline.

    """

    webapp.adapter._local.request_timeline = timeline

    return timeline

    # Disabled code path: bug 623199, ideally we would use this code path.

    request.annotations['timeline'] = timeline