Nil returned from a method that is expected to return a non-null value

Question

I'm implementing UIKeyInput, UITextInputTraits, and UITextInput and with that I'm required to implement:

- (NSArray *)selectionRectsForRange:(UITextRange *)range
{
    return nil;
}

However, in analyzing my project I get: "nil returned from a method that is expected to return a non-null value".

What would be the correct way to get rid of this? Should I do an abort?

"Should I just terminate the program"? What does that mean? Pull the plug on your computer? — matt, Aug 28 '17 at 22:56

score 3 · Answer 1 · answered Aug 29 '17 at 00:04

Actually if you look at the header source, the method has NS_ASSUME_NONNULL_BEGIN tag attached to it. So in short the selectionRectsForRange becomes a non null return method.

//
//  UITextInput.h
//  UIKit
//
//  Copyright (c) 2009-2017 Apple Inc. All rights reserved.
//

#import <CoreGraphics/CoreGraphics.h>
#import <UIKit/UITextInputTraits.h>
#import <UIKit/UIResponder.h>

...

NS_ASSUME_NONNULL_BEGIN  // <--- HERE!
..
- (CGRect)firstRectForRange:(UITextRange *)range;
- (CGRect)caretRectForPosition:(UITextPosition *)position;
- (NSArray *)selectionRectsForRange:(UITextRange *)range NS_AVAILABLE_IOS(6_0);

So you cannot return null or nil. Instead return an empty array like so:

- (NSArray *)selectionRectsForRange:(UITextRange *)range
{
    return @[];
}

score 2 · Accepted Answer · answered Aug 28 '17 at 22:55

2

Don't return nil. If you have no UITextSelectionRects to return, return an empty array.

answered Aug 28 '17 at 22:55

matt

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Is there a cleaner way than just initializing an NSArray to a length of 1 and returning it? – Ser Pounce Aug 28 '17 at 23:23
Not a length of 1. Empty. – matt Aug 28 '17 at 23:27
Never mind I just did: return [[NSArray alloc] init]; – Ser Pounce Aug 28 '17 at 23:27
2

`return @[];` perhaps? – matt Aug 28 '17 at 23:30

Nil returned from a method that is expected to return a non-null value

2 Answers2

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