[dev] Notifications and embedded hyperlinks

[Jon Parise]

I've been toying with the idea of modifying the Notification package
to support the notion of embedded hyperlinks (or other markup).  My
specific use case involves embedded a link to the Nag edit page when a
new task is created from within IMP.

The current 'status' listener calls htmlspecialchars() on the message
text.  This prevents HTML markup from being included in the current
implementation, so something needs to change to support this.

Assuming everyone agrees this is a good idea, I've come up with these
possible solutions:

1. Allow markup to be included in the existing notification messages.

    This would involve removing htmlspecialchars() from the 'status'
    listener.  An caller that might need the htmlspecialchars()
    behavior will have to call it directly before the event is pushed
    into the notification system.

    Also, not all listeners may be able to handle embedded markup.

2. Introduce a new parameter -- $flags -- to the Notification::push()
   call.  A new NOTIFICATION_ALLOW_MARKUP flag will be introduced that
   allow the listeners to "do the right thing" with the message text
   when it comes time to render it.

    This approach involves touching a lot of the Notification code.
    It's a one-time hit because the $flags field is generic enough to
    support additional flags in the future.  This will still result in
    listener-specific behavior, however: some listeners may be able to
    render the markup while others will just convert it to entities or
    strip it out entirely.

3. Introduce a new notification type: horde.message.markup (or
   something) that listeners can choose to handle.

    This involves not changes o the Notification API.  The handlers
    can be updated to support this new type individually.  Any
    additional encoding is the responsibility of the caller.  The
    downside is that, if the current listener chooses not to handle
    this new type, the event will essentially be lost.

Opinions?

-- 
Jon Parise (jon at horde.org) :: The Horde Project (http://horde.org/)