We now disconnect ourselves if we don't get the server's response to a
keepalive request within 30s. This way we will eventually disconnect if
the network goes away but the socket is not closed.*
* See code.google.com/p/chromium/issues/detail?id=197841 and
https://stackoverflow.com/questions/11755605/chrome-websocket-connection-not-closed-when-browser-closed
We will then try to reconnect once a minute (See 8a10c96);
Keepalives belong at this level anyway, since the format is defined by
both the websocket resource protocol and our specific server url
structure.
// FREEBIE
Turns out we can get ABNORMAL_CODE (1006) for disconnects where (for
instance) we pause the background page too long. However, in these cases
there is no preceeding ErrorEvent. In contrast, when we have bad
authentication credentials, there is an ErrorEvent. Thus, this change
ensures that we only reconnect if there was no Error.
Closes#173
Previously, in the event of a failed websocket auth, we would attempt to
reconnect once a second ad infinitum. This changeset ensures that we
only reconnect automatically if the socket closed 'normally' as
indicated by the code on the socket's CloseEvent. Otherwise, show a
'Websocket closed' error on the inbox view.
Ideally we would show a more contextual error (ie, 'Unauthorized'), but
unfortunately the actual server response code is not available to our
code. It can be observed in the console output from the background page,
but programmatically, we only receive the WebSocket CloseEvent codes
listed here:
https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent#Status_codes
The websocket error message is displayed by a normally-hidden but ever
present socket status element. Clicking this element will immediately
refresh the background page, which will try again to open the websocket
connection.
