20 Feb
2017
20 Feb
'17
5:43 p.m.
Hi,
On 20 Feb 2017, at 12:20, Guillaume Delhumeau
<guillaume.delhumeau(a)xwiki.com> wrote:
Hello XWikiers.
In the current roadmap, I have the responsibility to create a notification
system.
The need has been described in the following page:
http://design.xwiki.org/xwiki/bin/view/Proposal/NotificationSystemforApps
In a few words, applications need to send some messages that could be
displayed either on the top menu (the "notification" menu we already have
and where the Watchlist options are located) or by e-mail. Users should see
quickly the new messages and have the ability to mark some messages has
read. Use-cases: having a notification when a new message has been posted
on the Forum application, having a notification when the user has been
invited to join a wiki, having a notification when a new meeting is
organized, etc... Users will also have the ability select which type of
notifications she wants to receive.
Displaying messages is not the difficult part. Neither is sending emails.
What is complicated is the storage of them.
Since a user should still see messages she marked as read, we need to store
the status of each notification for each user. It could be done either on
the server-side (in a NotificationUser table), either on the client-side
(using local storage:
https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage).
I actually see 3 ways to implement the storage:
A - When a notification is sent, a job creates all the NotificationUser
entries needed (1 per user) with the status "unread”.
[snip]
B - Create the NotificationUser entries lazily
[snip]
C - Store the status on the client-side
[snip]
On this page:
http://design.xwiki.org/xwiki/bin/view/Proposal/NotificationCenterforAppsIm…
I have explained they way I consider the implementation. There is a notion
of NotificationType for example that might interest you.
I'm hesitating between option A and C. I think B has no really benefits.
The rest of the mechanism can be implemented right away, so I'm starting
it. Please answer quickly if you think I am doing something wrong.
What do you think?
I’ve brainstormed with Guillaume and here’s the result of our thinking so far:
* Reuse the AS storage for sorting the events since it’s made for this. In the future move
to a noSQL storage (see http://markmail.org/message/35crgocabxb3tfwk)
* Create 2 new tables for:
** Storing the audience for a given event. In one of the paramN fields of the AS table,
store the key to the audience table which lists all specific users and groups to which the
event is addressed to. When no audience is specified it means it’s addressed to everyone.
** Storing the read status per user. Note: Don’t store it in the browser since this is too
fragile and we want users to be able to switch device and still keep their read statuses.
* In the future move the audience and status data inside the nosql store as properties.
* In the future we should deprecate the watchlist since the Notification Manager can
handle this use case by considering that we can have an “app” called “system” or
“documents” that represents all documents in the wiki. For each app we need to be able to
specify to which events the user is registering for, including the ability to specify
fine-grained criteria such as “Register for all new blog posts that contain the word
‘xwiki’ in the title”. Thus the user should also be able to say “Register for all document
events located in the following wikis, spaces, pages”.
* When an event is sent by an app, don’t create an entry in the status table. Only create
an entry there when a user marks an event as read.
* So the idea is that the xwiki-platform-eventstream module should contain only the
storage of events (right now the storage is located in the AS module) and then
xwiki-platform-activitystream and xwiki-platform-notifications both use it. It’s even
likely IMO that the AS could disappear as such and that it would be a special case of the
notification module.
WDYT?
Thanks
-Vincent
Thanks