This method looks at the current view and its subview hierarchy for the text field that is currently the first responder. If it finds one, it asks that text field to resign as first responder. If the force parameter is set to YES, the text field is never even asked; it is forced to resign. [...]

If you would like to output the SQL being generated by Core Data, here is the quick steps: Go to Product -> Edit Scheme Choose Run YourAppName.app Add -com.apple.CoreData.SQLDebug 1 to the Arguments Passed On Launch panel

https://gist.github.com/1175468

Here is code snippet to parse a XML string to Core Data NSDate.