Book Image

RestKit for iOS

By : Taras Kalapun
Book Image

RestKit for iOS

By: Taras Kalapun

Overview of this book

<p>RestKit is an iOS framework for streamlining communication with web services, and it relies on the AFNetworking library that is used by thousands of app developers. It has an interface that is elegant and well designed, and it provides a powerful object-mapping engine that integrates well with the CoreData database. RestKit for iOS will teach you everything from loading a simple list of objects to creating a fully-featured app.<br /><br />RestKit for iOS delivers constructive tools and insights into app development that will benefit any app developer. The book starts with a simple example and then moves on to more complex ones as your knowledge increases. By the end of the guide, you will be able to build a fully-featured app that uses RESTful web services and performs CRUD object manipulation.<br /><br />RestKit for iOS will provide you with all the information you need to boost the development process of both simple and complex apps. Once you have executed a simple example and reviewed the basic theory, you will move on to more advanced concepts with descriptions of real-life scenarios and how to overcome bottlenecks. RestKit for iOS is full of real-life examples that show you how to simplify data loading, basic and advanced object mapping, metadata mapping, and routing. This book also teaches you about routing, RESTful object manipulation and synchronization, integration with the user interface, and caching</p>
Table of Contents (13 chapters)

Error mapping


If the server is capable of returning proper error messages in response, we will be able to map them and output directly to the user. So, if the server is capable of returning error message in the JSON response as follows:

{
  "error": "No matching database associated with this account",
  "code": 1005
}

Then, we can use it to show to the user. To do so, create an error mapping for the RKErrorMessage class as follows:

// You can map errors to any class
// RKErrorMessage is included within RestKit
RKObjectMapping *errorMapping = [RKObjectMapping mappingForClass:[RKErrorMessage class]];

// Map error information to the errorMessage property in our class
[errorMapping addPropertyMapping:[RKAttributeMapping attributeMappingFromKeyPath:nil toKeyPath:@"errorMessage"]];

// Anything in 4xx (Client errors)
NSIndexSet *clientErrorStatusCodes = RKStatusCodeIndexSetForClass(RKStatusCodeClassClientError);

// Anything in 5xx (Server errors)
NSIndexSet *serverStatusCodes = RKStatusCodeIndexSetForClass...