This will help us avoid some duplicate code when
we use input pills for stream-create.
See the long comment in set_up_handlers() for
more context.
We also rename:
submit_add_subscriber_form -> subscribe_new_users
Ideally set_up_handlers() would also extract the
concept of clearing the pills as soon as you either
hit enter or clicked on the Add button, but our
current paradigm for clearing pills when you edit
subscribers for an existing stream on the Subscribers
tab is that we wait for the server to acknowledge
the request. I believe this is a bit of a misfeature,
but I am punting on that change for now.
This is mostly a pure code move. A few small tweaks:
* The create() function is new.
* The new module doesn't assume a `pill_widget`
global.
This module represents the truly re-usable code
that can be shared during these two user actions:
* edit-stream subscribers (now)
* create-stream subscribers (future)
In both situations the input pill has (or will have)
essentially the same behavior, and the next commit
will tighten up the abstraction.
(The two processes will both also use fairly similar
ListWidgets, but the mechanics of managing the list
are going to be different, so we do not intend
to keep around stream_subscribers_ui in its current
name. More on that later.)
Anders Kaseorg
Steve Howell