@weakify(self);
[[[[[[[self requestAccessToTwitterSignal]
      then:^RACSignal *{
          @strongify(self)
          return self.searchText.rac_textSignal;
      }]
     filter:^BOOL(NSString *text) {
         @strongify(self)
         return [self isValidSearchText:text];
     }]
    throttle:0.5]
   flattenMap:^RACStream *(NSString *text) {
       @strongify(self)
       return [self signalForSearchWithText:text];
   }]
    deliverOn:[RACScheduler mainThreadScheduler]]
    subscribeNext:^(NSDictionary *jsonSearchResult) {
       NSArray *statuses = jsonSearchResult[@"statuses"];
       NSArray *tweets = [statuses linq_select:^id(id tweet) {
           return [RWTweet tweetWithStatus:tweet];
     }];
     [self.resultsViewController displayTweets:tweets];
 } error:^(NSError *error) {
     NSLog(@"An error occurred: %@", error);
 }];

//UserModel.h
@interface UserModel : NSObject
@property (nonatomic, copy)   NSString *desc;
@property (nonatomic, copy)   NSString *name;
@property (nonatomic, copy)   NSString *avatar;
@property (nonatomic, copy)   NSString *alt;
+ (instancetype)userWithDict:(NSDictionary *)dic;
@end

//UserModel.m
@implementation UserModel
+ (instancetype)userWithDict:(NSDictionary *)dic
{
    //采用的笨方法选择需要的几个数据
    UserModel *book = [[UserModel alloc] init];
    book.name = dic[@"name"];
    book.desc = dic[@"desc"];
    book.avatar = dic[@"avatar"];
    book.alt = dic[@"alt"];
    return book;
}
@end

#import "ViewController.h"
#import "RequestViewModel.h"
#import "DetailController.h"

@interface ViewController ()

@property (nonatomic, weak)   UITableView *tableView;
@property (nonatomic, strong) RequestViewModel *requesViewModel;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.title = @"RAC + MVVM";
    self.view.backgroundColor = [UIColor whiteColor];
    _requesViewModel = [[RequestViewModel alloc] init];
    
    UITableView *tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, ScreenWidth, ScreenHeight)];
    tableView.dataSource = self.requesViewModel;
    tableView.delegate = self.requesViewModel;
    [self.view addSubview:tableView];
    self.tableView = tableView;
    
    _requesViewModel.selectCommand = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(RACTuple *turple) {
        
        DetailController *detailVC = [[DetailController alloc] init];
        detailVC.sendObject = turple;
        [self.navigationController pushViewController:detailVC animated:YES];
        return [RACSignal empty];
    }];
    
    @weakify(self);
    [[[self.requesViewModel.reuqesCommand execute:nil]
     deliverOn:[RACScheduler mainThreadScheduler]]
     subscribeNext:^(NSArray *x) {
         @strongify(self);
         self.requesViewModel.models = x;
         [self.tableView reloadData];
    }];
}

@end

#import "RequestViewModel.h"
#import "UserModel.h"
#import "AFNetWorkHelp.h"
#import "LXTableViewCell.h"

@implementation RequestViewModel

- (instancetype)init
{
    if (self = [super init]) {
        [self initialBind];
    }
    return self;
}

- (void)initialBind
{
    _reuqesCommand = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {
        
        RACSignal *requestSignal = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
            
            NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
            parameters[@"q"] = @"iOS";
            parameters[@"count"] = @"30";
            NSString *urlStr = @"https://api.douban.com/v2/user";
            
            [AFNetWorkHelp getWithUrlString:urlStr withParam:parameters success:^(NSDictionary *responseDic) {
                
                // 请求成功调用
                // 把数据用信号传递出去
                [subscriber sendNext:responseDic];
                [subscriber sendCompleted];
                LogBlue(@"%@", responseDic);

            } failure:^(NSError *error) {
                
            }];
            
            return nil;
        }];
        
        // 在返回数据信号时，把数据中的字典映射成模型信号，传递出去
        return [requestSignal map:^id(NSDictionary *value) {
            NSArray *dictArr = value[@"users"];
            
            // 字典转模型，遍历字典中的所有元素，全部映射成模型，并且生成数组
#if 1       
            //这是正常方法
            NSArray *modelArr = [dictArr dicToModel:^id(id user) {
                return [UserModel userWithDict:user];
            }];
#else
            //这是ARC提供的遍历方法，简单
            NSArray *modelArr = [[dictArr.rac_sequence map:^id(id value) {
                return [UserModel userWithDict:value];
            }] array];
#endif
            return modelArr;
        }];
    }];
}

#pragma mark - UITableViewDelegate
//省略部分代理方法
......
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
    
    RACTuple *turple = [RACTuple tupleWithObjects:self.models[indexPath.row], indexPath, nil];
    [self.selectCommand execute:turple];
}

@end