Objective C - Custom view and implementing init method?

Question

I have a custom view that I want to be able to initialize both in-code and in nib.

What's the correct way to write both initWithFrame and initWithCoder methods? They both share a block of code that is used for some initialization.

Answer 1

The right thing to do in that case is to create another method containing the code that's common to both -initWithFrame: and -initWithCoder:, and then call that method from both -initWithFrame: and -initWithCoder::

- (void)commonInit {     // do any initialization that's common to both -initWithFrame:     // and -initWithCoder: in this method }  - (id)initWithFrame:(CGRect)aRect {     if ((self = [super initWithFrame:aRect])) {         [self commonInit];     }     return self; }  - (id)initWithCoder:(NSCoder*)coder {     if ((self = [super initWithCoder:coder])) {         [self commonInit];     }     return self; } 

Do heed the concerns outlined in Justin's answer, particularly that any subclasses must not override -commonInit. I used that name here for its illustrative value, but you'll probably want one that's more closely tied to your class and less likely to be accidentally overridden. If you're creating a purpose-built UIView subclass that's unlikely to be subclassed itself, using a common initialization method as above is perfectly fine. If you're writing a framework for others to use, or if you don't understand the issue but want to do the safest possible thing, use a static function instead.