xcode-nscoding

An Xcode-extension that automatically generates NSCoding-implementations from Objective-C properties.

Description

NSCoding implementations always follow a certain formula. To me, it's so standardized that it is just boilerplate when having many model objects. It's also easy to make a mistake, since NSCoding keys must always be correctly matched with their properties.

This extension aims to fix this, by automatically generating initWithCoder: and encodeWithCoder: functions from your object properties.

Example

The extension will convert the following properties:

@property (nonatomic, strong) NSNumber *objectNumber;
@property (assign, getter=isInteresting) BOOL interesting;
@property (nonatomic, assign) NSInteger anInteger;

Into the following NSCoding-implementations:

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if (self = [super init]) {
        self.objectNumber = [aDecoder decodeObjectOfClass:[NSNumber class] forKey:NSStringFromSelector(@selector(objectNumber))];
        self.interesting = [aDecoder decodeBoolForKey:NSStringFromSelector(@selector(interesting))];
        self.anInteger = [aDecoder decodeIntegerForKey:NSStringFromSelector(@selector(anInteger))];
    }
    return self;
}

- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeObject:self.objectNumber forKey:NSStringFromSelector(@selector(objectNumber))];
    [aCoder encodeBool:self.interesting forKey:NSStringFromSelector(@selector(interesting))];
    [aCoder encodeInteger:self.anInteger forKey:NSStringFromSelector(@selector(anInteger))];
}

Usage

In Xcode, select the properties you want NSCoding-implementations for, and choose `Editor -> NSCoding. In this menu, you will find three options:

Convert properties for encodeWithCoder: Converts the properties in place into encodeWithCoder:-compatible code.
Convert properties for initWithCoder: Same as above, but for initWithCoder:.
Copy NSCoding implementations Creates full implementations of encodeWithCoder: and initWithCoder: and copies them to your clipboard, without changing the source text.

Installation

Using the pre-built binary

Download the binary, and put it somewhere it won't bother you. You will only have to run this binary once to install the extension, but you need to keep it around since it contains the extension itself.

Compiling yourself

Clone the project and open it in Xcode, then Product -> Archive. Then, in Organizer, choose "Export..." and "Save as macOS-application". The app will run and install the extension. The extension may have to be enabled from your system preferences, in the Extensions-pane.