Jdimo

Jdimo is an Objective-C base class that is initialized with a dictionary (probably from your JSON response), and assigns dictionary values to all its (derived class's) typed @properties.

It supports nested types, arrays, NSString, NSNumber, NSDate and more.

Jdimo is NOT a JSON parser. For that, you have NSJSONSerialization.

The name sounds like JSON Dictionary to Model Object. Or something.

Examples

You have the following JSON:

{
	"name": "Foo",
	"amount": 13
}

and the following class:

@interface Product
@property (nonatomic, copy) NSString *name;
@property (nonatomic, retain) NSNumber *amount;
@end

@implementation Product
@end

with Jdimo, you can just inherit from ObjectModel class, and use initWithDictionary:

// Product.h
@interface Product : ObjectModel
@property (nonatomic, copy) NSString *name;
@property (nonatomic, retain) NSNumber *amount;
@end

// Product.m
@implementation Product
@end

// Some other code
NSDictionary *dictionary = /* parse the JSON response to a dictionary */;
Product *product = [[Product alloc] initWithDictionary:dictionary];

// Log
product.name // => Foo
product.amount // => 13

Nested Objects

Jdimo also converts nested objects to their destination type:

// JSON
{
	"name": "Foo",
	"category": {
		"name": "Bar Category"
	}
}

// ProductCategory.h
@interface ProductCategory : Jdimo
@property (nonatomic, copy) NSString *name;
@end

// ProductCategory.m
@implementation ProductCategory
@end

// Product.h
@interface Product : ObjectModel
@property (nonatomic, copy) NSString *name;
@property (nonatomic, retain) ProductCategory *category;
@end

// Product.m
@implementation Product
@end


// Code
NSDictionary *dictionary = /* parse the JSON response to a dictionary */;
Product *product = [[Product alloc] initWithDictionary:dictionary];

// Log
product.name // => Foo
product.category // => <ProductCategory>
product.category.name // => Bar Category

Arrays

Having fun so far?

Jdimo also supports arrays of a certain type:

// JSON
{
	"name": "Foo",
	"categories": [
		{ "name": "Bar Category 1" },
		{ "name": "Bar Category 2" },
		{ "name": "Bar Category 3" }
	]
}

// ProductCategory.h
@interface ProductCategory : Jdimo
@property (nonatomic, copy) NSString *name;
@end

// ProductCategory.m
@implementation ProductCategory
@end

// Product.h
@interface Product : ObjectModel
@property (nonatomic, copy) NSString *name;
@property (nonatomic, retain) NSArray *categories;
@end

// Product.m
@implementation Product

+ (Class)categories_class {
	return [ProductCategory class];
}

@end


// Code
NSDictionary *dictionary = /* parse the JSON response to a dictionary */;
Product *product = [[Product alloc] initWithDictionary:dictionary];

// Log
product.name // => Foo
product.categories // => <NSArray>
[product.categories count] // => 3
[product.categories objectAtIndex:1] // => <ProductCategory>
[[product.categories objectAtIndex:1] name] // => Bar Category 2

Notice the declaration of

+ (Class)categories_class {
	return [ProductCategory class];
}

it tells Jdimo what class of items the array holds.

Nested + Arrays = Trees

Jdimo can handle trees of data:

// JSON
{
	"name": "1",
	"children": [
		{ "name": "1.1" },
		{ "name": "1.2",
		  children: [
			{ "name": "1.2.1",
			  children: [
				{ "name": "1.2.1.1" },
				{ "name": "1.2.1.2" },
			  ]
			},
			{ "name": "1.2.2" },
		  ]
		},
		{ "name": "1.3" }
	]
}

// ProductCategory.h
@interface ProductCategory : Jdimo
@property (nonatomic, copy) NSString *name;
@property (nonatomic, retain) NSArray *children;
@end

// ProductCategory.m
@implementation ProductCategory

+ (Class)children_class {
	return [ProductCategory class];
}

@end


// Code
NSDictionary *dictionary = /* parse the JSON response to a dictionary */;
ProductCategory *category = [[ProductCategory alloc] initWithDictionary:dictionary];

// Log
category.name // => 1
category.children // => <NSArray>
[category.children count] // => 3
[category.children objectAtIndex:1] // => <ProductCategory>
[[category.categories objectAtIndex:1] name] // => 1.2

[[[category.children objectAtIndex:1] children] objectAtIndex:0] // => <ProductCategory>
[[[[category.children objectAtIndex:1] children] objectAtIndex:0] name] // => 1.2.1.2

How does it work?

Runtime API. The class's properties are read in runtime and assigns all values from dictionary to these properties with NSObject setValue:forKey:. For Dictionaries, Jdimo instantiates a new class, based on the property type, and issues another initWithDictionary. Arrays are only a list of items such as strings (which are not converted) or dictionaries (which are treated the same as other dictionaries).

Installation

Just copy Jdimo.m+.h and JdimoRuntimeHelper.m+.h to your project, create a class, inherit, use the initWithDictionary and enjoy!

Or pod 'jdimo'

Testing

In Xcode, hit CMD+U under iPhone simulator scheme.

REALLY Good to know

Jdimo classes also conforms to NSCoding protocol

So you get initWithCoder/encodeWithCoder for free.

You can look at the tests for real samples.

Alternatives

Contributors

Antoine Coeur @Coeur
Elad Ossadon @elado
Yosi Taguri @yosit

Coeur/jdimo