ReactiveCocoa + MVVM模拟用户登陆

步骤

1. 在ViewController中单向绑定数据

2. 在ViewModel做数据处理，验证数据，与网络回调处理

3. 在VC中刷新UI

1.ViewController.m中代码

//
//  ViewController.m
//  RACLogInDome
//
//  Created by 马克吐温° on 2018/1/17.
//  Copyright © 2018年 马克吐温°. All rights reserved.
//

#import "ViewController.h"
#import "ReactiveObjC.h"
#import "DataViewModel.h"
#import "MBProgressHUD+HM.h"
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UITextField *accountTF;
@property (weak, nonatomic) IBOutlet UITextField *passwordTF;
@property (weak, nonatomic) IBOutlet UIButton *loginBT;
@property (nonatomic, strong)DataViewModel *dataViewModel;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self bindDataAndRefreshView];
}

- (void)bindDataAndRefreshView{
    /**<数据绑定*/
    RAC(self.dataViewModel, account) = self.accountTF.rac_textSignal;
    RAC(self.dataViewModel, password) = self.passwordTF.rac_textSignal;
    
    /**<绑定信号*/
    self.loginBT.rac_command = [self.dataViewModel verifyAccountAndPasswor];
    
    /**<信号回调--正确信号*/
    [[self.loginBT.rac_command executionSignals]subscribeNext:^(id  _Nullable x) {
        [MBProgressHUD showMessage:@"正在登陆"];
        [x subscribeNext:^(id  _Nullable x) {
            [MBProgressHUD hideHUD];
            [MBProgressHUD showSuccess:x];
        }];
    }];
    
    /**<信号回调--错误信号*/
    [self.loginBT.rac_command.errors subscribeError:^(NSError * _Nullable error) {
        [MBProgressHUD showMessage:error.domain];
    }];
}

- (DataViewModel *)dataViewModel{
    if (!_dataViewModel) {
        _dataViewModel = [[DataViewModel alloc] init];
    }
    return _dataViewModel;
}

@end

2.ViewModel中的代码

//
//  DataViewModel.h
//  RACLogInDome
//
//  Created by 马克吐温° on 2018/1/17.
//  Copyright © 2018年 马克吐温°. All rights reserved.
//

#import 
@class RACCommand;
@interface DataViewModel : NSObject
@property (nonatomic, copy)NSString *account;/**<账号*/
@property (nonatomic, copy)NSString *password;/**密码*/


/**
 验证账号密码

 @return RACCommand信号量
 */
- (RACCommand *)verifyAccountAndPasswor;

@end

//
//  DataViewModel.m
//  RACLogInDome
//
//  Created by 马克吐温° on 2018/1/17.
//  Copyright © 2018年 马克吐温°. All rights reserved.
//

#import "DataViewModel.h"
#import "ReactiveObjC.h"
#import "MBProgressHUD+HM.h"
#define verifyNumber 3
@interface DataViewModel()
@end

@implementation DataViewModel
#pragma mark -
#pragma mark ----------本地验证用户名&&密码----------
- (RACCommand *)verifyAccountAndPasswor{
    /**<验证账号*/
    RACSignal *accountSignal = [RACObserve(self, account) map:^id _Nullable(NSString *str) {
        return @(str.length >= verifyNumber ? YES : NO);
    }];
    /**<验证密码*/
    RACSignal *passwordSignal = [RACObserve(self, password) map:^id _Nullable(NSString *str) {
        return @(str.length >= verifyNumber ? YES : NO);
    }];
    /**<合并账号,密码 信号量*/
    RACSignal *combineLatest = [RACSignal combineLatest:@[accountSignal, passwordSignal] reduce:^id (NSNumber *accountValue, NSNumber *passwordValue){
        return @([accountValue boolValue] && [passwordValue boolValue]);
    }];
    /**<返回验证结果*/
    return [[RACCommand alloc] initWithEnabled:combineLatest signalBlock:^RACSignal * _Nonnull(id  _Nullable input) {
        return [self logInWithAccount:self.account password:self.password];
    }];
}
#pragma mark -
#pragma mark ----------模拟网路登陆----------
- (RACSignal *)logInWithAccount:(NSString *)account password:(NSString *)password{
    return [RACSignal createSignal:^RACDisposable * _Nullable(id  _Nonnull subscriber) {
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            /**<请求成功发送信号*/
            [subscriber sendNext:@"登陆成功"];
            [subscriber sendCompleted];
        });
        return nil;
    }];
}
@end

简单的一个RAC+MVVM的Dome,可以看出将许多验证逻辑，请求逻辑，数据加工逻辑放在了VM中，逻辑更加清晰，有利于在VM中单独进行单元测试。很大程度减少VC中的代码量，同时使用RAC使代码更加优雅易读，使用信号量代替Block delegate来传递信息。

Dome: https://github.com/wudiyule/RACLogInDome