> On 6 Mar 2015, at 11:34, Dave <d...@looktowindward.com> wrote: > > Hi, > >> I think you might need to provide some more info about your architecture and >> I also think you need to ask your questions in the xpc devforums list: >> https://devforums.apple.com/community/mac/coreos/xpc >> <https://devforums.apple.com/community/mac/coreos/xpc> because if you get an >> answer there it is more likely to be well informed. > > Thanks Kevin, I’ll take a look at the XPC forum. > >> I am a little confused by your terminology. I’d call an Application a >> process that a user interacts with (that displays the menu bar) but I >> wouldn’t call the four items listed above Applications. > > > Yes, it is confusing and I think I called it this because it’s referred to as > a “Faceless Background Application” (FBA) in some places. I’ve just started > this project and I’m a little confused about some of the things I need to do > myself, but I think I have it clear in my head what is needed now, there are > two things that are needed: > > 1. Have some kind of background monitor (FBA?) that detects certain > conditions and when a trigger condition is met, send it to a regular Mac > Application (with a UI). There is no need for any of the Application(s) to > send anything to this FBA.
This approach will awkward to implement because it is opposite to the way XPC is designed. The XPC design is intended for a process such as a (LoginItem, LaunchAgent, LaunchDaemon, XPC service) to provide a service, so when your GUI Application needs a task to be done that is provided by a service it sends that service a message which the service handles and then sends a reply back to the application using the connection initiated by the application. It is likely possible to achieve the opposite goal by the application first sending a message to your monitor and the monitor keeps the connection open, details of how to achieve this other than just waiting to reply until the monitor trigger condition is met I can’t help with. > > 2. Have some kind of “Service" that owns an SQLite database and allows other > applications to send read/write requests to it. This would be a launch agent or a login item. > > I was confusing the two before, probably because in the specification I have, > the two are shown as one unit. At the moment I am concentrating on the > Monitor (1) above, as the database manager is not needed until further on in > the project. > > Given the that I have two “applications” (for want of a better term) > LTWMonitor and LTWAppX, then on the face of it and ignoring any OS > requirements for the moment, this is what needs to happen: > > LTWMonitor will be Launched when the User Logs. > LTWMonitor will then launch LTWAppX as part of its initialisation. > LTWAppX will launch and do nothing, waiting for an “Event” from LTWMonitor. If I was you I would consider putting your LTWAppX in the list of the users login items and after it starts it launches the monitor by sending the monitor a XPC request. > > Once this has happened: > > If LTWMonitor detects a Trigger condition, it will send it to LTWAppX. > When LTWAppX receives the message from LTWMonitor, it take the appropriate > Actions (e.g. display an appropriate UI) for the message received. > > Given this, should I be considering XPC for the UIMonitor? One concern I have > it what it needs to be very responsive and as far as I know XPC is the > fastest solution and is the preferred modern way of achieving this. Performance wise I am happy with XPC but then your requirements may be different. Kevin _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
