[RFC][PATCH] Policer extension point, and improvement on user preference box programming

[Patrick Schaaf]

This is a request for comments, and a moderately large patch to serve as a foundation for the request.

The focus is on improvements to the user preference panels, and especially on a new way to selectively remove subscribers, before announcements are distributed, under various conditions.

My trac installation and development system is still running 0.11.7, so I'm making these changes against the 0.11/ branch of AnnouncerPlugin, in the hope that code did not diverge too much to make this useless.

I'll create this ticket with the patch attached, then write a comment with more elaboration on the contained features.

I'm looking forward to any comments you might have, and directions on how likely it is to get this integrated.

[Patrick Schaaf]

Ground covered:

IAnnouncementPolicer

A new extension point, IAnnouncementPolicer, is provided. Implementors are called after the list of all subscriptions has been built, and before the distributors are called. Implementors can then remove subscribers from the list, to suppress announcements to them by various criteria.
Interface and central implementation in api.py

The patch contains five exemplary implementations of policers. Some of them have user preferences, all going into a single box in the preferences panel.

To enable the policers, you have to put this in trac.ini:

[components]
announcerplugin.policer.* = enabled

Use the admin panel plugin configuration to selectively enable or disable them.

The five policers in the patch provide the following functions, each in a separate policer. All individual trac.ini options go to the [announcer] section:

• observe WIKI_VIEW or TICKET_VIEW permission, per subscriber. There is no trac.ini option (or user preference :) for this, just enabling or disabling of the policer module.

• a replacement for the ignore_cc_changes option, previously found in producers/ticket.py - both with a backwards compatible trac.ini default, and user preference overriding of that.

  ignore_cc_changes = true
  

• a reimplementation of my ignore_status_only patch (#9031), also providing user preferences overriding the trac.ini defaults

  ignore_status_only = true
  no_ignore_status = accepted, super_important_status
  

• do not announce changes to the user that the user made herself (by user preference and trac.ini default) This is a replacement for the NeverNotifyUpdaterPlugin, which no longer works when you use AnnouncerPlugin.

  policer.never_notify_updater = true
  

• completely disable announcements for the given user (by their preference) Might be useful when people go on holiday. Has no trac.ini default.

User Preference Boxes

While keeping the current preferences box interface, a similar, new extension point IAnnouncementPreferenceSettingProvider can be used to define, from several different implementors, settings that should go into the same box.
Interface in api.py, implementation in pref.py

• two helper functions, user_setting() and get_user_setting(), are provided in pref.py for use by any submodule that wants to retrieve or store user preferences. These helpers could be used by several of the existing modules, but this patch does not contain that.

• A configuration method is provided to sort the boxes in the user preference panel, and to sort the settings in shared boxes as per the new IAnnouncementPreferenceSettingProvider interface.

  pref.order = email, legacy, policer_suppressions, emailaddress
  pref.order.policer_suppressions = never_notify_at_all, never_notify_updater
  

  If no configuration is made, boxes are sorted alphabetically by their box names. That approach provides a stable order of the boxes, regardless of plugin and extension point order, which seems to be quite shaky.

[Patrick Schaaf]

minimal updates

[Patrick Schaaf]

respin - now with revert-user-settings-to-defaults functionality

[Patrick Schaaf]

The -V2 patch moves the user setting helpers from pref.py to a new file userpref.py.

Functionality added: when user settings are present in the settings DB, i.e. system defaults from trac.ini are overridden, a new checkbox is rendered at the right margin of the settings box, which can be checked + on submit, the settings in that line will return to their trac.ini defaults, and are removed from the DB.

Calling sites (in policer/*.py) are also cleaned up a bit, with more compact helper function signatures.

The templates use a table now - is there a better way to optionally add a right-floating checkbox that keeps vertical alignment with the settings it stands for?

[Patrick Schaaf]

teaser - this is how the policer settings box looks like now

[Ryan J Ollos]

Please upgrade to Trac 1.2, which has integrated the core of AnnouncerPlugin. Please raise the issue on the ​trac:MailingList if you encounter the issue with Trac 1.2.