UberBuilder is a set of convenience methods provided to make building flexible, immutable objects a simple task.
- iOS 7.0+ / Mac OS X 10.10+
- Xcode 6.0
- Cocoapods 0.37.1
- Add UberBuilder as a line in your Podfile
pod 'UberBuilder/Core', '~> 1.0' - Run
pod install - Add
#import <UberBuilder/UBBuilder.h>to the file(s) that you wish the use it in.
Below we define a buildable Container class with readonly properties that is intended to be created via the [Container build:] method.
// Container.h
#import <UIKit/UIKit.h>
typedef void (^BlockType)();
@protocol Container <NSObject>
@property (nonatomic, readonly, copy) NSString *string;
@property (nonatomic, readonly) NSNumber *number;
@property (nonatomic, readonly, copy) NSArray *array;
@property (nonatomic, readonly, copy) BlockType block;
@property (nonatomic, readonly) UIEdgeInsets edgeInsets;
@end
@protocol ContainerBuilder <NSObject>
@property (nonatomic, copy) NSString *string;
@property (nonatomic) NSNumber *number;
@property (nonatomic, copy) NSArray *array;
@property (nonatomic, copy) BlockType block;
@property (nonatomic) UIEdgeInsets edgeInsets;
@end
@interface Container : NSObject <Container>
@property (nonatomic, readonly) BOOL didAwakeFromBuilder;
+ (instancetype)build:(void (^)(id <ContainerBuilder>))builder;
+ (instancetype)copy:(Container *)buildable builder:(void (^)(id <ContainerBuilder>))builder;
@endIt is important to note that the Container class conforms publicly to the read-only Container protocol. The ContainerBuilder protocol is exposed to allow setting of builder properties in the builder block seen in the [Container build:] and [Container copy:builder:] methods.
The implementation for the Container class should contain an extension to the class that conforms to the UBBuildable and ContainerBuilder protocols. Each property from the builder protocol must be synthesized.
#import "Container.h"
#import <UberBuilder/UBBuilder.h>
@interface Container () <UBBuildable, ContainerBuilder>
@end
@implementation Container
@synthesize string = _string;
@synthesize number = _number;
@synthesize array = _array;
@synthesize block = _block;
@synthesize edgeInsets = _edgeInsets;
#pragma mark - Constructor
- (instancetype)init {
self = [super init];
if (self) {
// Set default values here, if desired
self.array = @[];
}
return self;
}
#pragma mark - UBBuilder
+ (instancetype)build:(void (^)(id <ContainerBuilder>))builder
{
return [UBBuilder build:self builder:builder];
}
+ (instancetype)copy:(Container *)buildable builder:(void (^)(id <ContainerBuilder>))builder
{
return [UBBuilder copy:buildable class:self builderProtocol:@protocol(ContainerBuilder) builder:builder];
}
#pragma mark - UBBuildable
- (void)ub_awakeFromBuilder
{
// Take some action post-build. For example, perform validation, ensure required parameters are set, etc...
NSParameterAssert(self.array);
}
@endThe builder methods simply make a forwarding call to [UBBuilder build:builder] and [UBBuilder copy:class:builderProtocol:builder:] methods.
In a practical exercise below, we create a Container instance and have the flexibility to assign any combination of the properties that we choose. After the object is created, there are no public mutators defined and the consumer is unable to mutate without using the runtime.
- (void)testCopyBuildable
{
Container *buildable = [Container build:^(id <ContainerBuilder> builder) {
builder.string = @"Test";
builder.number = @237;
builder.block = ^{};
builder.edgeInsets = UIEdgeInsetsMake(0.0, 1.0, 2.0, 3.0);
}];
Container *buildableCopy = [Container copy:buildable builder:nil];
XCTAssertEqualObjects(buildable.string, buildableCopy.string);
XCTAssertEqualObjects(buildable.number, buildableCopy.number);
XCTAssertEqualObjects(buildable.array, buildableCopy.array);
XCTAssertEqualObjects(buildable.block, buildableCopy.block);
XCTAssertTrue(UIEdgeInsetsEqualToEdgeInsets(buildable.edgeInsets, buildableCopy.edgeInsets));
}