On Friday 12 February 2010 11:42:26 Graham Murray wrote: > Alan McKinnon <alan.mckin...@gmail.com> writes: > > On Friday 12 February 2010 09:44:01 Graham Murray wrote: > >> Volker Armin Hemmann <volkerar...@googlemail.com> writes: > >> > so how do you propose that a network connection manager tells a > >> > broweser or mail app that they are offline? > >> > >> Why does the app need to know? Browsers normally have an online/offline > >> menu selection and if you try to browse to a site when your network is > >> offline then the browser will generate the appropriate error message. In > >> any case, these notifications are only really of use on a single-homed > >> non LAN connected system. On an office LAN, you may well be able to > >> still access your mail server but a problem means that you cannot access > >> any web sites. > > > > A network connection manager tells apps when the machine's interface goes > > down, not when the gateway is no longer available. > > > > You have these two things conflated. > > Which still does not explain why the applications need to know when a > network interface goes down but does not need to know when (for example) > the ADSL connection (via an external router) to the 'outside world' goes > down[1]. As far as both the application and the user are concerned the > effect is exactly the same in both cases - the application is > offline. If it is considered important to inform the application of one, > then it should be equally important to inform the application of the > other. If a network interface goes offline then the user needs to know, > so as to take corrective action, but I do not think that telling the web > browser and mail applications is the correct way of informing the user. > > [1] Which in my experience, while not a frequent occurrence, happens > far more frequently than the network interface going down.
The network beyond the machine is completely outside the control of any app on the machine, that's why it is not checked for. Besides, if the gateway is down, the LAN is usually still up local things are probably accessible. The most common case of the interface going down is the wireless kill switch pressed or the LAN cable pulled out. That's something the user would like to know due to many of them doing it a LOT. The system can send out a notify for that, which apps can chose to listen to or not. The most common case would be a popup saying "A cable is unplugged". Mailers can then take themselves offline if they wish, and that ability depends on what the dev decided to support. Just because you don't personally see the point does not mean a. It is pointless, or b. The message bus should not support such things -- alan dot mckinnon at gmail dot com
