ObjcExtensionProperty

Overview

ObjcExtensionProperty is a collection of macro defines for adding getter and setter methods for objective-c calsses and extensions.

• Fast adding getter/setter methods with just one line code
• Add weak properties for calss extension (also with just one line code)
• Easy to add lazy property getter method with just one line code

Usage

use any of the macro definions below to implement your getter/setter(s)

//instance variable backed lazy getter method macro define
#define __GETTER_LAZY_IVAR(Class,name,initializer...)

//dynamic property lazy getter method
#define __GETTER_LAZY(Class,name,initializer...)

//common object type property setter method
#define __SETTER(name,setter,association)

//common object type property getter method
#define __GETTER(Class,name) -(Class *)name

//common object type property setter method with additional costomize code
#define __SETTER_CUSTOMIZE(name,setter,association,customizeCode...)

//common object type property getter method provide a default return value
#define __GETTER_DEFAULT(Class,name,defaultValue)

//common weak object type property setter method
#define __SETTER_WEAK(name,setter)

//common weak object type property getter method
#define __GETTER_WEAK(Class,name)

//primitive type property setter method
#define __SETTER_PRIMITIVE(type,name,setter,NSNumberMethod)

//primitive type property getter method
#define __GETTER_PRIMITIVE(type,name,NSNumberMethod)

//primitive type property getter method with a default return value
#define __GETTER_PRIMITIVE_DEFAULT(type,name,defaultValue,NSNumberMethod)

Example

Add various kinds of properties for class extension

Let see how easy it is to add various kinds of properties though ObjcExtensionProperty. In this example we assume that you want to add some properties for UIView

//UIView+DyanmicTest.h

@interface UIView (DyanmicTest)

@property (nonatomic, strong) NSString *dynProperty; //common object property
@property (nonatomic) int dynPrimitiveValue; //primitive type property
@property (nonatomic, weak) NSString *dynWeakProperty; //weak property
@property (nonatomic, lazy) NSString *lazyProperty; //lazy property

@property (nonatomic) CGFloat *dynHeight; //default is 480.0

//check the code in .m file
@property (nonatomic,strong) UITableView *tableView;
@property (nonatomic) CGFloat addHeight;

@end

add backed getter/setter methods for properties in .m file

//UIView+DyanmicTest.m
@implementation UIView (DyanmicTest)

//common getter/setter
__SETTER(dynProperty, setDynProperty:, OBJC_ASSOCIATION_RETAIN)
__GETTER(NSString, dynProperty)

//primitive type getter/setter
__SETTER_PRIMITIVE(int,dynPrimitiveValue, setDynPrimitiveValue:, numberWithInt:)
__GETTER_PRIMITIVE(int, dynPrimitiveValue, intValue)

//weak reference getter/setter
__SETTER_WEAK(dynWeakProperty, setDynWeakProperty:)
__GETTER_WEAK(NSString, dynWeakProperty)

//lazy property getter
__GETTER_LAZY(NSString, lazyProperty,[NSString stringWithFormat:@"lazy created on %@",[NSDate date]])

//getter with default return value
__SETTER_PRIMITIVE(CGFloat, dynHeight, setDynHeight:, numberWithDouble:)
__GETTER_PRIMITIVE_DEFAULT(CGFloat, dynHeight, 480.0, doubleValue)


//setter with customize code
__SETTER_CUSTOMIZE(tableView, setTableView:, OBJC_ASSOCIATION_RETAIN, {
    UITableView *tbv = tableView;
    tbv.dataSource = self;
    tbv.delegate = self;
})
__GETTER(UITableView, tableView)

//primitive setter with cusomize code
__SETTER_PRIMITIVE_CUSTOMIZE(CGFloat, addHeight, seAddHeight:, numberWithDouble:, {
    self.frame = CGRectMake(0, 0, 320, self.frame.size.height+addHeight);
})
__GETTER_PRIMITIVE(CGFloat, addHeight, doubleValue)

@end

Without ObjcExtensionProperty, you'll find that implementing these getter/setter methods is cumbersome, you will have to write much more code. especially for lazy properties.

//UIView+DyanmicTest.m

@implementation UIView (DyanmicTest)

//lazyProperty's getter method without ObjcExtensionProperty

//define a key
const char lazyPropertyKey;
// implement the getter
-(NSString *)lazyProperty{
    NSString *retValue =  objc_getAssociatedObject(self, &lazyPropertyKey);
    if(!retValue) {
        retValue = [NSString stringWithFormat:@"lazy created on %@",[NSDate date]];
        objc_setAssociatedObject(self, &lazyPropertyKey, retValue, OBJC_ASSOCIATION_RETAIN);
    }
    return retValue;
}
.

//other properties getter/setter methods
.
.
.
.

@end

Add weak property for class extension

objc_setAssociatedObject() doesn't provide a weak reference type, but instead with OBJC_ASSOCIATION_ASSIGN, which means whenever you access to a object that was previousely deallocated, you will cetainly got a crash. with ObjcExtensionProperty you don't have to face such a problem anymore.

//define weak property in extension's .h file
@property (nonatomic, weak) NSString *dynWeakProperty; //weak property

//implement weak property's getter/setter methods
__SETTER_WEAK(dynWeakProperty, setDynWeakProperty)
__GETTER_WEAK(NSString, dynWeakProperty)

Add lazy property's getter method

ObjcExtensionProperty can easy to add getter method for lazy properties both for ivar backed properties(through __GETTER_LAZY_IVAR()) and in calss extensions(through __GETTER_LAZY)

lazy getter method for ivar backed property

//define lazy property
@interface RRViewController ()
@property (nonatomic,lazy) HttpClient *client;
@end

//
@implementation RRViewController
{
    HttpClient *_client;
}

//lazy getter method for self.client
__GETTER_LAZY_IVAR(HttpClient, client, [[HttpClient alloc]initWithUrl:@"https://github.com/Roen-Ro"])

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    NSLog(@"log _client.url:%@",_client.url); //null 
    NSLog(@"log self.client.url:%@",self.client.url); //https://github.com/Roen-Ro
}

//....
@end

Requirements

ios 5.0, mac os 9.0

Installation

ObjcExtensionProperty is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'ObjcExtensionProperty'

Or drag and drop files in 'ObjcExtensionProperty' directory directly into your xcode projects

Author

Roen(罗亮富), [email protected]

License

ObjcExtensionProperty is available under the MIT license. See the LICENSE file for more info.