A good application for ReactiveCocoa and MVVM

• 标题是英文的，只是在为托福做准备，所以希望在任何可以的地方练习一下英文的说和写。

• 本篇不再介绍基础的MVVM和RAC知识，所以在看本篇文章时，请确定你已经读了上一篇关于RAC+MVVM的文章，或者你已经对MVVM和RAC已经有很多的了解，你也可以直接阅读。

• 请带着批判的眼光来审视这篇文章，因为没有什么是完美的，假如可以催生出你更多的想法，那我花时间来写这篇文章也是很有价值的，

使用MVVM和RAC会解决你什么问题？

代码更加“紧密”：

-(LeftImageButton *)subjectHomework_button{
if (!_subjectHomework_button) {
    _subjectHomework_button=[[LeftImageButton alloc] init];
    _subjectHomework_button.left_imageView.image=[UIImage imageNamed:@"项目制学习作业"];
    _subjectHomework_button.right_label.text=@"项目制学习作业布置";
    _subjectHomework_button.backgroundColor=fifty_nine_BACKGROUND_COLOR;
    [[_subjectHomework_button rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(__kindof UIControl * _Nullable x) {
        SNSubjectHomeworkViewController *subjectHomework_VC=[[SNSubjectHomeworkViewController alloc] init];
        [self.navigationController pushViewController:subjectHomework_VC animated:true];
    }];
}
return _subjectHomework_button;
}

[[[NSNotificationCenter defaultCenter] rac_addObserverForName:GOT_INFORMATION_NOTI object:nil] subscribeNext:^(NSNotification * _Nullable x) {
    [self setHeadImage];
}];

VC真的瘦下来了：

#pragma mark - 初始化UI

#pragma mark - 懒加载

#pragma mark - 代理

#pragma mark - target action

#pragma mark - Maonry

#pragma mark - other 只有本页面会使用的工具方法

@property(nonatomic,strong)UITableView *tableView;

-(UITableView *)tableView{
if (!_tableView) {
    _tableView=[[UITableView alloc] init];
    _tableView.delegate=self;
    _tableView.dataSource=self;
    _tableView.layer.cornerRadius=20.0;
    _tableView.backgroundColor=[UIColor whiteColor];
    _tableView.separatorInset=UIEdgeInsetsMake(0,SNTrueHeight(40), 0, SNTrueHeight(40));//top left bottom right 左右边距相同
    _tableView.separatorStyle=UITableViewCellSeparatorStyleSingleLine;

    [_tableView registerClass:[MailTableViewCell class] forCellReuseIdentifier:teacher_mail_cell_reuse];
}
return _tableView;
}

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface TeacherMailViewModel : NSObject

@property(nonatomic,strong,readonly)RACCommand *command;
@property(nonatomic,strong,readonly)NSArray *mailArray;
/**
 获得邮箱数据
 */
-(void)getMailInformations;

@end

-(void)getMailInformations;

@property(nonatomic,strong,readonly)RACCommand *command;

-(void)getMailInformations{
@weakify(self);
self.command = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {
    @strongify(self);
    return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
        @strongify(self);

        NSMutableDictionary *header=[NSMutableDictionary dictionaryWithObject:[[UserInfoHandler sharedUserInfoHandler] userToken] forKey:@"token"];
        NSMutableDictionary *body=[NSMutableDictionary dictionaryWithObject:@"nothing" forKey:@"nothing"];

        [[SNAFNetManager sharedManager] requestWithURLString:API_URL_messageTraining header:header parameters:body subModel:[TeacherMailModel class] success:^(BasicResponseModel * _Nonnull successData) {
            self.mailArray=successData.data;
            //发送订阅信号
            [subscriber sendNext:@""];
            //发送结束信号
            [subscriber sendCompleted];
        } failure:^(BasicResponseModel * _Nonnull failureData) {

        } progressPercentBlock:^(float percent) {

        }];

        return nil;
    }];
}];
}

@property(nonatomic,strong)TeacherMailViewModel *viewModel;

-(TeacherMailViewModel *)viewModel{
if (!_viewModel) {
    _viewModel=[[TeacherMailViewModel alloc] init];

    [_viewModel getMailInformations];
}
return _viewModel;
}

[command execute:nil]

- (void)subscribeNextViewModel {
@weakify(self);
//将命令执行后的数据交给controller
[self.viewModel.command.executionSignals.switchToLatest subscribeNext:^(id _Nullable x) {
    @strongify(self);
    [self.tableView reloadData];
}];

//执行command
[self.viewModel.command execute:nil];
}

[subscriber sendCompleted];

[self.viewModel.command.executionSignals.switchToLatest subscribeNext:^(id _Nullable x) {
    @strongify(self);
    [self.tableView reloadData];
}];

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return self.viewModel.mailArray.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
MailTableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:teacher_mail_cell_reuse];
if (cell==nil) {
    cell=[[MailTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:teacher_mail_cell_reuse];
}

cell.viewModel_teacher=self.viewModel.mailArray[indexPath.row];

return cell;
}

#import <UIKit/UIKit.h>
#import "SNMailModel.h"
#import "TeacherMailModel.h"
NS_ASSUME_NONNULL_BEGIN

@interface MailTableViewCell : UITableViewCell
@property(nonatomic,strong)TeacherMailModel *viewModel_teacher;
@end

//老师端数据绑定
[RACObserve(self, viewModel_teacher.content) subscribeNext:^(NSString *  _Nullable x) {
    self.detail_label.text=x;
}];
[RACObserve(self, viewModel_teacher.updateDate) subscribeNext:^(NSString *  _Nullable x) {
    self.date_label.text=x;
}];