NSObject+Properties.h

// Foundation NSObject+Properties.h
//
// Copyright © 2015, Roy Ratcliffe, Pioneering Software, United Kingdom
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the “Software”), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED “AS IS,” WITHOUT WARRANTY OF ANY KIND, EITHER
// EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO
// EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
//------------------------------------------------------------------------------

@import Foundation;

@interface NSObject (Properties)

/// Uses the Objective-C run-time to obtain the object class' property names.
+ (NSArray *)propertyNames;

/// Obtains names of class properties then uses key-value coding to access the
/// property values by name. Answers a dictionary of property name-value
/// pairs. The dictionary excludes @c nil valued properties.
- (NSDictionary *)properties;

@end

NSObject+Properties.m

// Foundation NSObject+Properties.m
//
// Copyright © 2015, Roy Ratcliffe, Pioneering Software, United Kingdom
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the “Software”), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED “AS IS,” WITHOUT WARRANTY OF ANY KIND, EITHER
// EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO
// EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
//------------------------------------------------------------------------------

#import "NSObject+Properties.h"

#import <objc/runtime.h>

@implementation NSObject (Properties)

+ (NSArray *)propertyNames
{
    unsigned int count;
    NSMutableArray *propertyNames = [NSMutableArray array];
    objc_property_t *propertyList = class_copyPropertyList(self, &count);
    if (propertyList) {
        for (NSUInteger index = 0; index < count; index++) {
            const char *name = property_getName(propertyList[index]);
            [propertyNames addObject:[NSString stringWithUTF8String:name]];
        }
        free(propertyList);
    }
    return [propertyNames copy];
}

- (NSDictionary *)properties
{
    NSMutableDictionary *properties = [NSMutableDictionary dictionary];
    for (NSString *name in [[self class] propertyNames]) {
        id value = [self valueForKey:name];
        if (value) {
            properties[name] = value;
        }
    }
    return [properties copy];
}

@end