extend number-checker component

[LennyLinux]

@mozilla/appmaker#503

[simonwex]

That onChange event is used by the designer to see when it should save the app. What are you trying to do here?

[LennyLinux]

i added a checkbox in the editable panel to switch between input field and subscription channel as compare value source.

if you connect the subscription channel, the checkbox should be checked.
if you disconnect the subscription channel, the checkbox should be unchecked.

or

if you check the checkbox the subscription channel should be connected
if you uncheck the checkbox the subscription channel should be disconnected

here I tried to get notified if a subscription channel is (dis)connected.
atm there is no dedicated subscription-channel-connected-event, just a generic change event if a channel is connected. bit of a hack.

maybe the checkbox is needless and the present subscription channel is is clear enough?
that would simplify the code a lot.

connected

disconnected

[LennyLinux]

I reverted the previous commit.
The component now simply provides an subscription channel setNumber
which sets the checkAgainst attribute.

From ui perspective it might be a good idea to disable the input field when the setNumber channel is connected ?