NSCocoaErrorDomain Error Code 4

I'm a newbie . Is there an example code base I can look at that shows how to 1 ) fire up JSON queries/reposes to/from multiple websites in parallel,2) have each taks/thread process info and write it to a central (shared) array of objects3) then wait for a parallel tasks to finish3) process the info collected on shared array data.I'm assuming this is about correct usage of asynchronous queues, and some tricks with a synchronous/wait for completion method. need to see the handling of hte dance. Also how to ensure the common global data object being written to safely from multiple parallel tasks.pointers to example code much appreciated

I am a new developer and had a question about developing. I have an idea to improve on an app that comes with Iphone when you buy one. Is there a way you can code that enhancement onto the existing app? Or have a way you can attatch the change to that core app?Thanks!Steve

Hello All,I’ve created application which logs motion activity of user with CoreMotion framework and M7-chip functionality (I’m using CMMotionActivityManager).Application works fine in foreground. But I need to check that event occurred in 3-7 seconds frame in background mode.And I need to range iBeacons - check entering to specified zone in background mode and activate my test for the motion event.According following review http://developer.radiusnetworks.com/2013/11/13/ibeacon-monitoring-in-the-background-and-foreground.htmlthe time for detection is about 4 minutes (in average and up to 15 minutes) in background mode.Does exist any method or workaround to grab data for motion activity and ranging iBeacon in the background with better accuracy?- I need to check that event occurred in 3-7 seconds frame and notify user.My concept application works in the following way:1. I’ve activated background mode flags for CoreLocation and Audio (it plays audio signal on event detection).2. At start it requests au

Who had this problem - error: linker command failed with exit code 1 (use -v to see invocation)

This worked in Xcode 6. Xcode used to replace spaces with %20 and work. I've tried with spaces, backslash before spaces, quoting the string, and double quoting the string. Xcode won't even try to hit the server, probably some parsing error. Using %20 appears to crash Xcode. In fact, I had to delete my old repo in the list from an earlier version of Xcode to even see the list in Xcode 7 beta.

OS X Cocoa App.I have a Popover window that allows the user to choose a colour for a line on a graph.It uses an NSColorWell. When the user clicks in the well, the Colour Picker appears - which is good.When the user is done, they click away from the Popover and it disappears, but unless they specifically dismiss the colour picker it remains on screen.How can I programatically dismiss the colour picker?See the following screen shots for the sequence of events I am referring to. In Screen Shot 4 I would like the colour picker to disappear.Screen Shot 1Screen Shot 2Screen Shot 3Screen Shot 4Thanks!