iOS下使用restkit测试restful架构下的数据交互

这里mark下，忙完手里的测试以后写上restful的示例。下面直接说ios下如何使用。

这篇文章写的比较精简。目前只写了get方法。post delete,put 部分下次在补上。

准备工作

首先需要知道restful走的是json协议的数据。为了测试，需要利用服务器返回一段json。大家可以选用熟悉的方法返回。

这里说一个比较简单的学习测试方法。

mac下面开启webshare功能。也就是网络共享。

(10.9以后需要下载http://clickontyler.com/web-sharing/)

对于老的版本。在系统偏好设置->共享下面应该会有设置。

打开launchpad 输入ter 打开命令行。

输入命令

cd /Library/WebServer/Documents
sudo vim articles.json

按住快捷键i，复制粘贴内容

{ "articles": [
    { "title": "RestKit Object Mapping Intro",
      "body": "This article details how to use RestKit object mapping...",
      "author": "Blake Watters",
      "publication_date": "7/4/2011"
    },
    { "title": "RestKit 1.0 Released",
      "body": "RestKit 1.0 has been released to much fanfare across the galaxy...",
      "author": "Blake Watters",
      "publication_date": "9/4/2011"
    }]
}

Esc切换到视图以后。输入

:wq

同理在articles2.json文件内写入

{ "articles": [
    { "title": "RestKit Object Mapping Intro",
      "body": "This article details how to use RestKit object mapping...",
      "author": {
          "name": "Blake Watters",
          "email": "blake@restkit.org"
      },
      "publication_date": "7/4/2011"
    }]
}

安装cocoapods包管理工具

在命令行下输入

gem install cocoapods
pod setup

等待安装完成
其他内容可以参考学习 http://blog.devtang.com/blog/2012/12/02/use-cocoapod-to-manage-ios-lib-dependency/

建立工程

打开xcode5在桌面新建1个Master-Detail Controller 项目，命名为restkitDemo工程。关闭。

命令行输入

cd ~/Desktop/restkitDemo
vim Podfile

输入

platform :ios, '5.0'
pod 'RestKit', '~> 0.21.0'

pod 'RestKit/Testing', '~> 0.21.0'
pod 'RestKit/Search',  '~> 0.21.0'

:wq保存退出以后

执行

pod install

安装restKit包。

安装完成以后输入

open restkitDemo.xcworkspace

打开项目工程。

编写代码

基本的对象映射

新建Article文件。文件中实现1个从NSobject派生的类。

拷贝替换为一下代码

@interface Article : NSObject
@property (nonatomic, copy) NSString* title;
@property (nonatomic, copy) NSString* body;
@property (nonatomic, copy) NSString* author;
@property (nonatomic) NSDate*   publicationDate;
@end

切换到MasterViewController.m中。在

#import "DetailViewController.h"

下链接2个头文件。

#import "Article.h"
#import <RestKit/RestKit.h>

修改ViewDidLoad方法代码为

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.

    [self.refreshControl beginRefreshing];
    [self loadArticles];
}

接着添加如下代码

- (void) loadArticles
{
    RKObjectMapping* articleMapping = [RKObjectMapping mappingForClass:[Article class]];
    [articleMapping addAttributeMappingsFromDictionary:@{
                                                         @"title": @"title",
                                                         @"body": @"body",
                                                         @"author": @"author",
                                                         @"publication_date": @"publicationDate"
                                                         }];
    
    RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:articleMapping
                                                                                            method:RKRequestMethodAny
                                                                                       pathPattern:nil
                                                                                           keyPath:@"articles"
                                                                                       statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
    
    NSURL *url = [NSURL URLWithString:@"http://127.0.0.1/articles"];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    RKObjectRequestOperation *objectRequestOperation = [[RKObjectRequestOperation alloc] initWithRequest:request
                                                                                     responseDescriptors:@[responseDescriptor]];
    [objectRequestOperation setCompletionBlockWithSuccess:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
        RKLogInfo(@"Load collection of Articles: %@", mappingResult.array);
        if (!_objects) {
            _objects = [[NSMutableArray alloc] init];
        }
        [_objects removeAllObjects];
        [_objects addObjectsFromArray:mappingResult.array];
        [self.refreshControl endRefreshing];
        [[self tableView] reloadData];
    } failure:^(RKObjectRequestOperation *operation, NSError *error) {
        RKLogError(@"Operation failed with error: %@", error);
    }];
    [objectRequestOperation start];
}

修改tableView:cellForRowAtIndexPath:方法代码为

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];

    Article *object = _objects[indexPath.row];
    cell.textLabel.text = object.title;
    cell.detailTextLabel.text = object.author;
    return cell;
}

接下来修改detail中cell的style.

编译运行，没有意外会看到如下效果

对象与之间的关系映射

修改loadArticles方法代码为以下代码

    RKObjectMapping *authorMapping = [RKObjectMapping mappingForClass:[Author class]];
    [authorMapping addAttributeMappingsFromArray:@[@"name", @"email"]];
    
    RKObjectMapping *articleMapping = [RKObjectMapping mappingForClass:[Article class]];
    [articleMapping addAttributeMappingsFromDictionary:@{
                                                         @"title": @"title",
                                                         @"body": @"body",
                                                         @"publication_date": @"publicationDate"
                                                         }];
    [articleMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"author"
                                                                                   toKeyPath:@"author"
                                                                                 withMapping:authorMapping]];
    RKResponseDescriptor * responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:articleMapping
                                                                                             method:RKRequestMethodAny
                                                                                        pathPattern:nil
                                                                                            keyPath:@"articles"
                                                                                        statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
    NSURL *url = [NSURL URLWithString:@"http://127.0.0.1/articles2"];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    RKObjectRequestOperation *objectRequestOperation = [[RKObjectRequestOperation alloc] initWithRequest:request
                                                                                     responseDescriptors:@[responseDescriptor]];
    [objectRequestOperation setCompletionBlockWithSuccess:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
        RKLogInfo(@"Load collection of Articles: %@", mappingResult.array);
        if (!_objects) {
            _objects = [[NSMutableArray alloc] init];
        }
        [_objects removeAllObjects];
        [_objects addObjectsFromArray:mappingResult.array];
        [self.refreshControl endRefreshing];
        [[self tableView] reloadData];
    } failure:^(RKObjectRequestOperation *operation, NSError *error) {
        RKLogError(@"Operation failed with error: %@", error);
    }];
    [objectRequestOperation start];

修改tableView:cellForRowAtIndexPath:方法的代码为：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];

    Article *object = _objects[indexPath.row];
    cell.textLabel.text = object.title;
    cell.detailTextLabel.text = object.author.name;
    return cell;
}

修改Article.h中代码为

#import <Foundation/Foundation.h>

@interface Author : NSObject
@property (nonatomic, copy) NSString* name;
@property (nonatomic, copy) NSString* email;
@end

@interface Article : NSObject
@property (nonatomic, copy) NSString* title;
@property (nonatomic, copy) NSString* body;
@property (nonatomic) Author* author;
@property (nonatomic) NSDate* publicationDate;
@end

Article.m中代码为

#import "Article.h"

@implementation Author

@end

@implementation Article

@end

自此修改完成。编译运行。你会看到

关键部分

按照restkit的设计思路。

1个完整的过程分为

1：建立数据映射表。

2：建立返回的响应处理方式(增删改查的控制，构造中填写数据映射表)

3：新建1个url请求(注意，这里可以构造比较复杂的查询)

4：建立request操作，提交请求和返回处理方式。在block中处理成功与错误的返回。返回回来的数据会自动处理为对象。

分析下来还是比较好理解的。