Code example:

    #import &lt;UIKit/UIKit.h&gt;
    IB_DESIGNABLE
    @interface LOLView : UIView
    @property (nonatomic) IBInspectable UIColor *someColor; 
    @end

The equivalents are IB_DESIGNABLE and IBInspectable—see [the documentation for Objective C examples](https://developer.apple.com/library/ios/recipes/xcode_help-IB_objects_media/chapters/CreatingaLiveViewofaCustomObject.html#//apple_ref/doc/uid/TP40014224-CH41-SW1).

Also, this year&#39;s WWDC video &quot;What&#39;s New in Interface Builder&quot; has its examples in Swift, but the presenter also mentions the Objective C equivalents in passing.

This seems like it should be fairly easy, but I&#39;m not finding the answer.  I have a form where I need to validate that a selection has been made from a radio group.  I tried using the &#39;required&#39; attribute on the radio buttons, but when the form is validated it complains unless all the radio buttons are selected (which is impossible by design).  

What is the proper way to validate a radio group selection in AngularJS?

    &lt;form name=&quot;myForm&quot; ng-submit=&quot;submitForm()&quot; ng-controller=&quot;ExampleController&quot;&gt;
      &lt;input type=&quot;radio&quot; ng-model=&quot;color&quot; value=&quot;red&quot; required&gt;  Red &lt;br/&gt;
      &lt;input type=&quot;radio&quot; ng-model=&quot;color&quot; value=&quot;green&quot; required&gt; Green &lt;br/&gt;
      &lt;input type=&quot;radio&quot; ng-model=&quot;color&quot; value=&quot;blue&quot; required&gt; Blue &lt;br/&gt;
      &lt;tt&gt;color = {{color | json}}&lt;/tt&gt;&lt;br/&gt;
      &lt;button type=&quot;submit&quot;&gt;Submit&lt;/button&gt;
    &lt;/form&gt;

Clicking the submit button in the Plnkr shows the behavior.

http://plnkr.co/edit/3qcIbMvJk19OvokcHe2N?p=preview

Validate Radio Button AngularJS

I&#39;m trying to get the most popular hackathons which requires ordering by the respective hackathon&#39;s `partipants-&gt;count()`. Sorry if that&#39;s a little difficult to understand.

I have a database with the following format:

    hackathons
        id
        name
        ...

    hackathon_user
        hackathon_id
        user_id

    users
        id
        name

The `Hackathon` model is:

    class Hackathon extends \Eloquent {
	    protected $fillable = [&#39;name&#39;, &#39;begins&#39;, &#39;ends&#39;, &#39;description&#39;];

	    protected $table = &#39;hackathons&#39;;

	    public function owner()
	    {
		    return $this-&gt;belongsToMany(&#39;User&#39;, &#39;hackathon_owner&#39;);
	    }

	    public function participants()
	    {
		    return $this-&gt;belongsToMany(&#39;User&#39;);
	    }

	    public function type()
	    {
		    return $this-&gt;belongsToMany(&#39;Type&#39;);
	    }
    }

And `HackathonParticipant` is defined as:

    class HackathonParticipant extends \Eloquent {
	
	    protected $fillable = [&#39;hackathon_id&#39;, &#39;user_id&#39;];

	    protected $table = &#39;hackathon_user&#39;;

	    public function user()
	    {
		    return $this-&gt;belongsTo(&#39;User&#39;, &#39;user_id&#39;);
	    }

	    public function hackathon()
	    {
		    return $this-&gt;belongsTo(&#39;Hackathon&#39;, &#39;hackathon_id&#39;);
	    }
    }

I&#39;ve tried `Hackathon::orderBy(HackathonParticipant::find($this-&gt;id)-&gt;count(), &#39;DESC&#39;)-&gt;take(5)-&gt;get());` but I feel like I made a big mistake (possibly the $this-&gt;id), because it doesn&#39;t work at all.

How would I go about trying to get the most popular hackathons which is based on the highest number of related hackathonParticipants?

Laravel OrderBy relationship count

I have an Objective-C UI component that I&#39;d like to make inspectable in Interface Builder with Xcode 6. Swift has the `@IBDesignable` and `@IBInspectable` declaration attributes. Are they available also in Objective-C? How are they used?

Xcode6: IBDesignable and IBInspectable with Objective-C

<p>I have an Objective-C UI component that I'd like to make inspectable in Interface Builder with Xcode 6. Swift has the <code>@IBDesignable</code> and <code>@IBInspectable</code> declaration attributes. Are they available also in Objective-C? How are they used?</p>


I am trying to have a transparent navigation bar in IOS 7 app. There is a full screen image in my application. I am also having a UITableView over that image. When I use the code below, image fits the screen as I want but UITableView goes under navigation bar.

in `viewDidLoad`

i use

    self.navigationController.navigationBar.shadowImage = [UIImage new];
    self.navigationController.navigationBar.translucent = YES;
    self.navigationController.view.backgroundColor = [UIColor clearColor];


it is being ok when I change to `self.navigationController.navigationBar.translucent = NO;` but then I lose transparency at navigation bar.

UITableView goes under translucent Navigation Bar

I am attempting to gain access to the main `NSBundle` to retrieve **version** and **build** information. Thing is, I want to try it in Swift, I know how to retrieve it in Objective-C with:

```objc
text = [NSBundle.mainBundle.infoDictionary objectForKey:@&quot;CFBundleVersion&quot;];
```

Yet I don&#39;t know where to start with Swift, I have attempted to write it in the new syntax with no avail.

Getting version and build information with Swift

I have a large import task I need to do with core data.    
Let say my core data model look like this:  

    Car
    ----
    identifier 
    type

I fetch a list of car info JSON from my server and then I want to sync it with my core data `Car` object, meaning:  
If its a new car -&gt; create a new Core Data `Car` object from the new info.  
If the car already exists -&gt; update the Core Data `Car` object.   

So I want to do this import in background without blocking the UI and while the use scrolls a cars table view that present all the cars.  
  
Currently I&#39;m doing something like this:  

    // create background context
    NSManagedObjectContext *bgContext = [[NSManagedObjectContext alloc]initWithConcurrencyType:NSPrivateQueueConcurrencyType];
    [bgContext setParentContext:self.mainContext];
    
    [bgContext performBlock:^{
        NSArray *newCarsInfo = [self fetchNewCarInfoFromServer]; 
        
        // import the new data to Core Data...
        // I&#39;m trying to do an efficient import here,
        // with few fetches as I can, and in batches
        for (... num of batches ...) {
            
            // do batch import...

            // save bg context in the end of each batch
            [bgContext save:&amp;error];
        }

        // when all import batches are over I call save on the main context
        
        // save
        NSError *error = nil;
        [self.mainContext save:&amp;error];
    }];
  
But I&#39;m not really sure I&#39;m doing the right thing here, for example:  

Is it ok that I use `setParentContext` ?  
I saw some examples that use it like this, but I saw other examples that don&#39;t call `setParentContext`, instead they do something like this:   
      
    NSManagedObjectContext *bgContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
    bgContext.persistentStoreCoordinator = self.mainContext.persistentStoreCoordinator;  
    bgContext.undoManager = nil;

  

Another thing that I&#39;m not sure is when to call save on the main context, In my example I just call save in the end of the import, but I saw examples that uses:  
        

    [[NSNotificationCenter defaultCenter] addObserverForName:NSManagedObjectContextDidSaveNotification object:nil queue:nil usingBlock:^(NSNotification* note) {
        NSManagedObjectContext *moc = self.managedObjectContext;
        if (note.object != moc) {
            [moc performBlock:^(){
                [moc mergeChangesFromContextDidSaveNotification:note];
            }];
        }
    }];  

As I mention before, I want the user to be able to interact with the data while updating, so what if I the user change a car type while the import change the same car, is the way I wrote it safe?



**UPDATE:**    
---------------------
Thanks to @TheBasicMind great explanation I&#39;m trying to implement option A, so my code looks something like:   

This is the Core Data configuration in AppDelegate: 
  

    AppDelegate.m  
    
    #pragma mark - Core Data stack
    
    - (void)saveContext {
        NSError *error = nil;
        NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
        if (managedObjectContext != nil) {
            if ([managedObjectContext hasChanges] &amp;&amp; ![managedObjectContext save:&amp;error]) {
                DDLogError(@&quot;Unresolved error %@, %@&quot;, error, [error userInfo]);
                abort();
            }
        }
    }  

    // main
    - (NSManagedObjectContext *)managedObjectContext {
        if (_managedObjectContext != nil) {
            return _managedObjectContext;
        }
        
        _managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
        _managedObjectContext.parentContext = [self saveManagedObjectContext];
        
        return _managedObjectContext;
    }
    
    // save context, parent of main context
    - (NSManagedObjectContext *)saveManagedObjectContext {
        if (_writerManagedObjectContext != nil) {
            return _writerManagedObjectContext;
        }
        
        NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
        if (coordinator != nil) {
            _writerManagedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
            [_writerManagedObjectContext setPersistentStoreCoordinator:coordinator];
        }
        return _writerManagedObjectContext;
    }  
  
And this is how my import method looks like now:  

    - (void)import {
        NSManagedObjectContext *saveObjectContext = [AppDelegate saveManagedObjectContext];
        
        // create background context
        NSManagedObjectContext *bgContext = [[NSManagedObjectContext alloc]initWithConcurrencyType:NSPrivateQueueConcurrencyType];
        bgContext.parentContext = saveObjectContext;
        
        [bgContext performBlock:^{
            NSArray *newCarsInfo = [self fetchNewCarInfoFromServer];
            
            // import the new data to Core Data...
            // I&#39;m trying to do an efficient import here,
            // with few fetches as I can, and in batches
            for (... num of batches ...) {
                
                // do batch import...
                
                // save bg context in the end of each batch
                [bgContext save:&amp;error];
            }
            
            // no call here for main save...
            // instead use NSManagedObjectContextDidSaveNotification to merge changes
        }];
    }  


And I also have the following observer:  

    [[NSNotificationCenter defaultCenter] addObserverForName:NSManagedObjectContextDidSaveNotification object:nil queue:nil usingBlock:^(NSNotification* note) {
        
        NSManagedObjectContext *mainContext = self.managedObjectContext;
        NSManagedObjectContext *otherMoc = note.object;
        
        if (otherMoc.persistentStoreCoordinator == mainContext.persistentStoreCoordinator) {
            if (otherMoc != mainContext) {
                [mainContext performBlock:^(){
                    [mainContext mergeChangesFromContextDidSaveNotification:note];
                }];
            }
        }
    }];

Core Data background context best practice

I love the swipe pack thats inherited from embedding your views in a `UINavigationController`.  Unfortunately i cannot seem to find a way to hide the `NavigationBar` but still have the touch pan swipe back `gesture`.  I can write custom gestures but I prefer not to and to rely on the `UINavigationController` back swipe `gesture` instead.

if I uncheck it in the storyboard, the back swipe doesn&#39;t work

![enter image description here][1]


  [1]: http://i.stack.imgur.com/4n4Dy.png

alternatively if I programmatically hide it, the same scenario.

&lt;!-- language: objective-c --&gt;

	- (void)viewDidLoad
	{
	    [super viewDidLoad];
	    [self.navigationController setNavigationBarHidden:YES animated:NO]; // and animated:YES
	}


Is there no way to hide the top `NavigationBar` and still have the swipe?

No Swipe Back when hiding Navigation Bar in UINavigationController

I am working with Map Kit in iOS 8 using Obj-C NOT SWIFT. I cannot get the device location it is set a 0.00, 0.00 and I am getting the error:

    Trying to start MapKit location updates without prompting for location authorization. Must call -[CLLocationManager requestWhenInUseAuthorization] or -[CLLocationManager requestAlwaysAuthorization] first.

I have implemented: ( I have tried only one at a time and no luck )

    if(IS_OS_8_OR_LATER) {
        [self.locationManager requestWhenInUseAuthorization];
        [self.locationManager requestAlwaysAuthorization];
    }
    [self.locationManager startUpdatingLocation]; 

And in info.plist

    NSLocationWhenInUseUsageDescription  :   App would like to use your location.
    NSLocationAlwaysUsageDescription  :  App would like to use your location.

I do get prompted to allow the app to use my location but after I agree nothing changes. The location is being showed as 0.00, 0.00.

Code for displaying users location:

    //Get Location
    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.distanceFilter = kCLDistanceFilterNone;
    self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    [self.locationManager startUpdatingLocation];
    
    MKCoordinateRegion region = { { 0.0, 0.0 }, { 0.0, 0.0 } };
    region.center.latitude = self.locationManager.location.coordinate.latitude;
    region.center.longitude = self.locationManager.location.coordinate.longitude;
    region.span.longitudeDelta = 0.005f;
    region.span.longitudeDelta = 0.005f;
    [mapView setRegion:region animated:YES];


Mike.

**EDIT: View Answer Below.

iOS 8 Map Kit Obj-C Cannot Get Users Location

I&#39;m learning Swift lang, but I cannot pass optional callback argument into function:

    func dismiss(completion: () -&gt; Void) {
        if (completion) {
            return self.dismissViewControllerAnimated(true, completion: completion)
        }
        self.dismissModalViewControllerAnimated(true)
    }

This shows me an error - ``Type () -&gt; Void does not conform to protocol &#39;LogicValue&#39;``

Any suggestions?

Passing optional callback into Swift function

I was folling this tutorial for Swift: https://www.raywenderlich.com/125311/make-game-like-candy-crush-spritekit-swift-part-1 and came across this code:

    func == (lhs: Cookie, rhs: Cookie) -&gt; Bool {
        return lhs.column == rhs.column &amp;&amp; lhs.row == rhs.row
    }

I wrote exactly that, but Xcode is giving my these errors:

    Consecutive declarations on a line must be separated by &#39;;&#39;
    Expected declaration operators are only allowed at global scope

I found this code from apple&#39;s documentation: https://developer.apple.com/documentation/swift/equatable

Which is very similar to what I wrote. Whats wrong? This seems like a bug to me. I am using Xcode 6 Beta 2

### EDIT:

This is my whole Cookie class:

    class Cookie: Printable, Hashable {
        var column: Int
        var row: Int
        let cookieType: CookieType
        let sprite: SKSpriteNode?
        
        init(column: Int, row: Int, cookieType: CookieType) {
            self.column = column
            self.row = row
            self.cookieType = cookieType
        }
        
        var description: String {
            return &quot;type:\(cookieType) square:(\(column),\(row))&quot;
        }
        
        var hashValue: Int {
            return row * 10 + column
        }
        
        func ==(lhs: Cookie, rhs: Cookie) -&gt; Bool {
            return lhs.column == rhs.column &amp;&amp; lhs.row == rhs.row
        }
    }


Swift Equatable Protocol

In my `TextViewTableViewCell`, I have a variable to keep track of a block and a configure method where the block is passed in and assigned.  
Here is my `TextViewTableViewCell` class: 

    //
    //  TextViewTableViewCell.swift
    //
    
    import UIKit
    
    class TextViewTableViewCell: UITableViewCell, UITextViewDelegate {
    
        @IBOutlet var textView : UITextView
    
        var onTextViewEditClosure : ((text : String) -&gt; Void)?
        
        func configure(#text: String?, onTextEdit : ((text : String) -&gt; Void)) {
            onTextViewEditClosure = onTextEdit
            textView.delegate = self
            textView.text = text
        }
        
        // #pragma mark - Text View Delegate
        
        func textViewDidEndEditing(textView: UITextView!) {
            if onTextViewEditClosure {
                onTextViewEditClosure!(text: textView.text)
            }
        }
    }

When I use the configure method in my `cellForRowAtIndexPath` method, how do I properly use weak self in the block that I pass in.  
Here is what I have without the weak self: 

    let myCell = tableView.dequeueReusableCellWithIdentifier(textViewCellIdenfitier) as TextViewTableViewCell
    myCell.configure(text: body, onTextEdit: {(text: String) in
       // THIS SELF NEEDS TO BE WEAK  
       self.body = text
    })
    cell = bodyCell

**UPDATE**: I got the following to work using `[weak self]`: 

    let myCell = tableView.dequeueReusableCellWithIdentifier(textViewCellIdenfitier) as TextViewTableViewCell
    myCell.configure(text: body, onTextEdit: {[weak self] (text: String) in
            if let strongSelf = self {
                 strongSelf.body = text
            }
    })
    cell = myCell

When I do `[unowned self]` instead of `[weak self]` and take out the `if` statement, the app crashes. Any ideas on how this should work with `[unowned self]`?


How to Correctly handle Weak Self in Swift Blocks with Arguments

I&#39;d like to create a protocol with a method that takes a generic input and returns a generic value. 

This is what I&#39;ve tried so far, but it produces the syntax error. 

&gt; Use of undeclared identifier T.

What am I doing wrong?

    protocol ApiMapperProtocol {
        func MapFromSource(T) -&gt; U
    }
    
    class UserMapper: NSObject, ApiMapperProtocol {
        func MapFromSource(data: NSDictionary) -&gt; UserModel {
            var user = UserModel() as UserModel
            var accountsData:NSArray = data[&quot;Accounts&quot;] as NSArray     
            return user
        } 
    }

How to create generic protocols in Swift?

Apple has a nice [explanation of Type (Class) Methods][1], however, their example looks like this:

    class SomeClass {
        class func someTypeMethod() {
            // type method implementation goes here
        }
    }
    SomeClass.typeMethod()

I see this exact same example parroted everywhere. My problem is, I need to call my Type Method from within an instance of my class, and that doesn&#39;t seem to compute.

I MUST be doing something wrong, but I noticed that Apple does not yet support Class Properties. I&#39;m wondering if I&#39;m wasting my time.

I tried this in a playground:

    class ClassA
    {
        class func staticMethod() -&gt; String { return &quot;STATIC&quot; }
    
        func dynamicMethod() -&gt; String { return &quot;DYNAMIC&quot; }
    
        func callBoth() -&gt; ( dynamicRet:String, staticRet:String )
        {
            var dynamicRet:String = self.dynamicMethod()
            var staticRet:String = &quot;&quot;
        
    //        staticRet = self.class.staticMethod() // Nope
    //        staticRet = class.staticMethod() // No way, Jose
    //        staticRet = ClassA.staticMethod(self) // Uh-uh
    //        staticRet = ClassA.staticMethod(ClassA()) // Nah
    //        staticRet = self.staticMethod() // You is lame
    //        staticRet = .staticMethod() // You&#39;re kidding, right?
    //        staticRet = this.staticMethod() // What, are you making this crap up?
    //        staticRet = staticMethod()  // FAIL
        
            return ( dynamicRet:dynamicRet, staticRet:staticRet )
        }
    }

    let instance:ClassA = ClassA()
    let test:( dynamicRet:String, staticRet:String ) = instance.callBoth()
    
Does anyone have a clue for me?

[1]: https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Methods.html

How to call Type Methods within an instance method

I am exploring iOS8 beta. I couldn&#39;t find the device console logs in &quot;Window-&gt;Devices-&gt;MyiPad&quot;. Can someone tell me how I can get the console logs?

How to get device console in Xcode6?

I&#39;ve updated to Xcode 6 beta 3 and see that the **[+ = -] buttons** in the storyboard corner are gone. Is there a way for me to zoom in and out on view controllers within a storyboard in Xcode 6?

Xcode 6 how to enable storyboard zoom?

I&#39;m trying to create a button with **rounded corners** and a **drop shadow**. No matter how I switch up, the button will not display correctly. I&#39;ve tried `masksToBounds = false` and `masksToBounds = true`, but either the corner radius works and the shadow does not or the shadow works and the corner radius doesn&#39;t clip the corners of the button.


    import UIKit
    import QuartzCore

    @IBDesignable
    class Button : UIButton
    {
        @IBInspectable var masksToBounds: Bool    = false                {didSet{updateLayerProperties()}}
        @IBInspectable var cornerRadius : CGFloat = 0                    {didSet{updateLayerProperties()}}
        @IBInspectable var borderWidth  : CGFloat = 0                    {didSet{updateLayerProperties()}}
        @IBInspectable var borderColor  : UIColor = UIColor.clearColor() {didSet{updateLayerProperties()}}
        @IBInspectable var shadowColor  : UIColor = UIColor.clearColor() {didSet{updateLayerProperties()}}
        @IBInspectable var shadowOpacity: CGFloat = 0                    {didSet{updateLayerProperties()}}
        @IBInspectable var shadowRadius : CGFloat = 0                    {didSet{updateLayerProperties()}}
        @IBInspectable var shadowOffset : CGSize  = CGSizeMake(0, 0)     {didSet{updateLayerProperties()}}
    
        override func drawRect(rect: CGRect)
        {
            updateLayerProperties()
        }
        
        func updateLayerProperties()
        {
            self.layer.masksToBounds = masksToBounds
            self.layer.cornerRadius = cornerRadius
            self.layer.borderWidth = borderWidth
            self.layer.borderColor = borderColor.CGColor
            self.layer.shadowColor = shadowColor.CGColor
            self.layer.shadowOpacity = CFloat(shadowOpacity)
            self.layer.shadowRadius = shadowRadius
            self.layer.shadowOffset = shadowOffset
        }
    }


  [1]: http://i.stack.imgur.com/Y1crs.png

Swift - Problems with corner radius and drop shadow

In Objective-C we can call `componentsJoinedByString` to produce a string with each element of the array separated by the supplied string. While Swift has a `componentsSeparatedByString` method on String, there doesn&#39;t appear to be the inverse of this on Array:

    &#39;Array&lt;String&gt;&#39; does not have a member named &#39;componentsJoinedByString&#39;

What is the inverse of `componentsSeparatedByString` in Swift?

Content Type	Original Author	Original Content on Stackoverflow
Question	mxb	View Question on Stackoverflow
Solution 1 - Objective C	Adam Waite	View Answer on Stackoverflow
Solution 2 - Objective C	Matt Gibson	View Answer on Stackoverflow

Xcode6: IBDesignable and IBInspectable with Objective-C

Objective C Problem Overview

Objective C Solutions

Solution 1 - Objective C

Solution 2 - Objective C

Laravel OrderBy relationship count

Validate Radio Button AngularJS

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