Making Swift Class available to Interface Builder [duplicate] - objective-c

Question

This question already has answers here:
Xcode - How to fix 'NSUnknownKeyException', reason: … this class is not key value coding-compliant for the key X" error?
(79 answers)
Closed 7 years ago.
I have an XCode Project which I was developing in objective C but now with Swift I have a few classes saved as .swift files. When I am referencing these as custom classes in the Interface Builder, they don't work and I get an error that the class doesn't exist.
What am I missing in terms of bridging the gap between the two? I have the header file to make the objective C available to Swift but not sure about the other way around
Thanks
2014-07-08 20:18:07.463 FoodForTeeth[22030:70b] Unknown class SecondViewController in Interface Builder file.
2014-07-08 20:18:07.496 FoodForTeeth[22030:70b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIViewController 0x8c85390> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key date.'
*** First throw call stack:
(
0 CoreFoundation 0x01acf5e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x018528b6 objc_exception_throw + 44
2 CoreFoundation 0x01b5f6a1 -[NSException raise] + 17
3 Foundation 0x01513c2e -[NSObject(NSKeyValueCoding) setValue:forUndefinedKey:] + 282
4 Foundation 0x0147ff3b _NSSetUsingKeyValueSetter + 88
5 Foundation 0x0147f493 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 267
6 Foundation 0x014e194a -[NSObject(NSKeyValueCoding) setValue:forKeyPath:] + 412
7 UIKit 0x00866cd5 -[UIRuntimeOutletConnection connect] + 106
8 libobjc.A.dylib 0x018647d2 -[NSObject performSelector:] + 62
9 CoreFoundation 0x01acab6a -[NSArray makeObjectsPerformSelector:] + 314
10 UIKit 0x0086582e -[UINib instantiateWithOwner:options:] + 1417
11 UIKit 0x006d7c95 -[UIViewController _loadViewFromNibNamed:bundle:] + 280
12 UIKit 0x006d843d -[UIViewController loadView] + 302
13 UIKit 0x006d873e -[UIViewController loadViewIfRequired] + 78
14 UIKit 0x006d8c44 -[UIViewController view] + 35
15 UIKit 0x006f2a72 -[UINavigationController _startCustomTransition:] + 778
16 UIKit 0x006ff757 -[UINavigationController _startDeferredTransitionIfNeeded:] + 688
17 UIKit 0x00700349 -[UINavigationController __viewWillLayoutSubviews] + 57
18 UIKit 0x0083939d -[UILayoutContainerView layoutSubviews] + 213
19 UIKit 0x0062fdd7 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 355
20 libobjc.A.dylib 0x0186481f -[NSObject performSelector:withObject:] + 70
21 QuartzCore 0x045ab72a -[CALayer layoutSublayers] + 148
22 QuartzCore 0x0459f514 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
23 QuartzCore 0x0459f380 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 26
24 QuartzCore 0x04507156 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 294
25 QuartzCore 0x045084e1 _ZN2CA11Transaction6commitEv + 393
26 QuartzCore 0x04508bb4 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 92
27 CoreFoundation 0x01a9753e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
28 CoreFoundation 0x01a9748f __CFRunLoopDoObservers + 399
29 CoreFoundation 0x01a753b4 __CFRunLoopRun + 1076
30 CoreFoundation 0x01a74b33 CFRunLoopRunSpecific + 467
31 CoreFoundation 0x01a7494b CFRunLoopRunInMode + 123
32 GraphicsServices 0x02ebc9d7 GSEventRunModal + 192
33 GraphicsServices 0x02ebc7fe GSEventRun + 104
34 UIKit 0x005c594b UIApplicationMain + 1225
35 FoodForTeeth 0x0001c42d main + 141
36 libdyld.dylib 0x02b5e701 start + 1
37 ??? 0x00000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
SecondViewController.swift
import UIkit
import CoreData
#objc(SecondViewController) class SecondViewController: UIViewController, UITextFieldDelegate {
#IBOutlet var txtTask: UITextField!
#IBOutlet var txtDesc: UITextField!
#IBOutlet var date: UIDatePicker!
#IBOutlet var dateDisplayLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
configureDatePicker()
}
func configureDatePicker() {
date.addTarget(self, action: "updateDatePickerLabel", forControlEvents: .ValueChanged)
updateDatePickerLabel()
}
func updateDatePickerLabel() {
dateDisplayLabel.text = dateFormatter.stringFromDate(date.date)
}
#lazy var dateFormatter: NSDateFormatter = {
let dateFormatter = NSDateFormatter()
dateFormatter.timeStyle = .ShortStyle
return dateFormatter
}()
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
//Events
#IBAction func btnAddTask_Click(sender: UIButton){
let appDel: foodforteethAppDelegate = UIApplication.sharedApplication().delegate as foodforteethAppDelegate
let context:NSManagedObjectContext = appDel.managedObjectContext
let ent = NSEntityDescription.entityForName("Food", inManagedObjectContext: context)
var newFood = food(entity: ent, insertIntoManagedObjectContext: context)
newFood.foodname = txtTask.text
newFood.date = dateFormatter.stringFromDate(date.date)
context.save(nil)
/*
taskMgr.addTask(txtTask.text, desc: dateFormatter.stringFromDate(date.date));
self.view.endEditing(true)
txtTask.text = ""
//txtDesc.text = ""
//self.tabBarController.selectedIndex = 0;*/
self.navigationController.popViewControllerAnimated(true)
}
//iOS touch functions
override func touchesBegan(touches: NSSet!, withEvent event: UIEvent!){
self.view.endEditing(true)
}
func textFieldShouldReturn(textField: UITextField!) -> Bool {
textField.resignFirstResponder();
return true
}
}

Answer 1

You need to read https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html
To import Swift code into Objective-C from the same target
Import the Swift code from that target into any Objective-C .m file
within that target using this syntax, and substituting the appropriate
name:
#import "ProductModuleName-Swift.h"
Any Swift files in your target will be visible in Objective-C .m files containing this import
statement. For information on using Swift from Objective-C code, see
Using Swift from Objective-C.