MVVM+Reactive Cocoa項目完整實例

前言

網上介紹Reactive Cocoa的使用文檔不少，可是應用demo要麼一帶而過，要麼過於龐大不適合初學者（大神寫的），本人自學一段時間後，略有心得，特地編寫了一個完整的demo，該demo徹底遵循MVVM架構設計。Github傳送門

本文並不適合無任何reactive cocoa基礎的童鞋，如需學習reactive cocoa基礎請參考。 最快讓你上手ReactiveCocoa之基礎篇 最快讓你上手ReactiveCocoa之進階篇 iOS ReactiveCocoa 最全經常使用API整理（可作爲手冊查詢） ReactiveCocoa 官方GitHub ReactiveCocoa v2.5 源碼解析之架構總覽

demo運行

• 運行前請先進行pod install
• 運行後，搜索框未輸入時，搜索按鈕不可用，在搜索框輸入電影名或導演名等，如張藝謀，搜索按鈕可用，點擊按鈕可獲得相關的電影搜索結果；
• demo網絡數據採用的豆瓣Api V2中的電影搜索功能；

程序說明

主界面

• 主界面包括兩個類HomeViewController和HomeViewModel，由於model過於簡單就直接定義在ViewModel中了
• HomeViewModel定義了搜索條件searchConditons字符串，並將字符串是否爲空與按鈕是否可用信號searchBtnEnableSignal綁定；
• HomeViewController則首先將ViewModel中的searchConditons字符串與輸入框內容綁定，再將搜索按鈕的enable屬性與ViewModel中的searchBtnEnableSignal綁定;
• 以上兩個步驟便可實現經過判斷輸入框內容是否爲空從而肯定搜索按鈕的enable屬性；
• 點擊按鈕後頁面跳轉；

HomeViewModel定義以下:

#import <Foundation/Foundation.h>
#import <ReactiveObjC.h>

@interface HomeViewModel : NSObject
@property (nonatomic, copy) NSString *searchConditons;

@property (nonatomic, strong, readonly) RACSignal  *searchBtnEnableSignal;
@end

複製代碼

#import "HomeViewModel.h"

@implementation HomeViewModel

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

- (void)setUp{
    [self setupSearchBtnEnableSignal];
}

- (void)setupSearchBtnEnableSignal {
    _searchBtnEnableSignal = [RACSignal combineLatest:@[RACObserve(self, searchConditons)] reduce:^id(NSString *searchConditions){
        return @(searchConditions.length);
    }];
}

@end
複製代碼

HomeViewController定義以下:

#import "HomeViewController.h"
#import "MovieViewController.h"
#import "UIButton+FillColor.h"
#import "HomeViewModel.h"
#import <UIButton+JKBackgroundColor.h>

@interface HomeViewController ()
@property (weak, nonatomic) IBOutlet UITextField *textContent;
@property (weak, nonatomic) IBOutlet UIButton *btnSearch;

@property(nonatomic, strong) HomeViewModel *homeVM;

@end

@implementation HomeViewController

-(HomeViewModel *)homeVM{
    if (!_homeVM) {
        _homeVM = [[HomeViewModel alloc]init];
    }
    
    return  _homeVM;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    _btnSearch.enabled = false;
    
    [_btnSearch setBackgroundColor:[UIColor lightGrayColor] forState:UIControlStateDisabled];
    [_btnSearch setBackgroundColor:[UIColor blueColor] forState:UIControlStateNormal];
    
    RAC(self.homeVM, searchConditons) = self.textContent.rac_textSignal;
    RAC(self.btnSearch, enabled) = self.homeVM.searchBtnEnableSignal;
    
    
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
- (IBAction)onClick:(UIButton *)sender {
    // 進入下一界面
    UIStoryboard * storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    MovieViewController * destViewController = [storyboard instantiateViewControllerWithIdentifier:@"MovieViewController"];
    destViewController.conditions = _textContent.text;
    [self.navigationController pushViewController:destViewController animated:YES];
    
}


@end

複製代碼

搜索結果界面

• 搜索結果界面包括3個類Movie和MovieViewModel以及MovieViewController；
• Movie包括電影名稱、時間、導演、主演、圖片；實際上，豆瓣Api V2返回的電影數據遠不止這麼多，這裏只選擇了一部分；

#import <Foundation/Foundation.h>

@interface Movie : NSObject

@property(nonatomic, strong) NSString * title;
@property(nonatomic, strong) NSString * year;
@property(nonatomic, strong) NSArray *casts;
@property(nonatomic, strong) NSArray *directors;
@property(nonatomic, strong) NSDictionary *images;

+ (instancetype)movieWithDict:(NSDictionary *)dict;

@end
複製代碼

#import "Movie.h"

@implementation Movie

+(instancetype)movieWithDict:(NSDictionary *)dict{
    Movie *movie = [[Movie alloc]init];
    movie.year = dict[@"year"];
    movie.title = dict[@"title"];
    movie.casts = dict[@"casts"];
    movie.directors = dict[@"directors"];
    movie.images = dict[@"images"];
    
    return movie;
}

@end
複製代碼

• MovieViewModel則包括了業務邏輯代碼：定義命令、網絡請求、獲取數據、發送數據，

注意: 這裏使用的是RACCommand，而不是RACSignal，初學者可能很難理解二者之間的差異，我的是這樣理解：RACSignal是單向的，就像1我的在作演講，觀衆聽到就結束了；而RACCommand是雙向的，演講者作演講，下面的觀衆聽到後還反饋了意見，而演講者對反饋還作了回覆。 該demo中，首先在MovieViewController中作出發出命令，MovieViewModel收到命令後進行網絡請求，並將獲取的網絡數據包發送出去，MovieViewController對收到的數據進行解析和顯示；

定義以下：

#import <Foundation/Foundation.h>
#import <ReactiveObjC.h>

@interface MovieViewModel : NSObject

@property (nonatomic, strong, readonly) RACCommand *requestCommand;
@property (nonatomic, copy, readonly) NSArray *movies;

@end
複製代碼

#import "MovieViewModel.h"
#import "NetworkManager.h"
#import "Movie.h"


@implementation MovieViewModel

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

- (void)setup {
    
    _requestCommand = [[RACCommand alloc] initWithSignalBlock:^RACSignal * _Nonnull(id  _Nullable input) {
        NSLog(@"%@", input);
        
        
        RACSignal *requestSignal = [RACSignal createSignal:^RACDisposable * _Nullable(id<RACSubscriber>  _Nonnull subscriber) {
            NetworkManager *manager = [NetworkManager manager];
            [manager getDataWithUrl:@"https://api.douban.com/v2/movie/search" parameters:input success:^(id json) {
                [subscriber sendNext:json];
                [subscriber sendCompleted];
            } failure:^(NSError *error) {
                
            }];
            
            return nil;
        }];
        return [requestSignal map:^id _Nullable(id  _Nullable value) {
            NSMutableArray *dictArray = value[@"subjects"];
            NSArray *modelArray = [dictArray.rac_sequence map:^id(id value) {
                return [Movie movieWithDict:value];
            }].array;
           NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"year" ascending:NO];
            _movies = [modelArray sortedArrayUsingDescriptors:@[sortDescriptor]];
            NSLog(@"%@",_movies.description);
            
            return nil;
        }];
    }];
    
}

@end
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• MovieViewController則包含：發送命令、數據解析、數據顯示； 定義以下:

#import <UIKit/UIKit.h>

@interface MovieViewController : UITableViewController

@property(nonatomic, copy)NSString *conditions;

@end
複製代碼

#import "MovieViewController.h"
#import "Movie.h"
#import "MovieViewModel.h"
#import "MovieCell.h"
#import <YYWebImage/YYWebImage.h>
#import <ProgressHUD.h>
#import <SVProgressHUD.h>
#import "UITableView+FDTemplateLayoutCell.h"

@interface MovieViewController ()
@property (nonatomic, strong)MovieViewModel *movieVM;
@end

@implementation MovieViewController

-(MovieViewModel *)movieVM{
    if (!_movieVM) {
        _movieVM = [[MovieViewModel alloc]init];
    }
    
    return _movieVM;

}

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [self.movieVM.requestCommand.executionSignals.switchToLatest subscribeNext:^(id x) {
        [self.tableView reloadData];
        [SVProgressHUD dismiss];
    }];
    
    NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
    parameters[@"q"] = _conditions;
    [self.movieVM.requestCommand execute:parameters];
    [SVProgressHUD show];
    
    self.tableView.fd_debugLogEnabled = YES;  
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    return self.movieVM.movies.count;
}

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
    return [tableView fd_heightForCellWithIdentifier:@"cellID" configuration:^(MovieCell* cell) {
        [self configureCell:cell atIndexPath:indexPath];
    }];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    MovieCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cellID" forIndexPath:indexPath];
    
    [self configureCell:cell atIndexPath:indexPath];
    
    
    return cell;
}

- (void)configureCell:(MovieCell *)cell atIndexPath:(NSIndexPath *)indexPath {
    
    Movie *movie = self.movieVM.movies[indexPath.row];
    
    NSDictionary *dicImage = movie.images;
    NSString *imageStr = dicImage[@"large"];
    NSURL *imageUrl = [NSURL URLWithString:imageStr];
    
    // progressive
    [cell.movieImageView yy_setImageWithURL:imageUrl options:YYWebImageOptionProgressive];
    
    // progressive with blur and fade animation (see the demo at the top of this page)
    [cell.movieImageView yy_setImageWithURL:imageUrl options:YYWebImageOptionProgressiveBlur | YYWebImageOptionSetImageWithFadeAnimation];
    
    cell.title.text = movie.title;
    NSString *year = @"上映時間:";
    cell.year.text = [year stringByAppendingString:movie.year];
    NSString *directors = @"導演：";
    for (NSDictionary *dict in movie.directors) {
        NSString *directname = dict[@"name"];
        directors = [directors stringByAppendingFormat:@"%@,",directname];
    }
    cell.directors.text = directors;
    NSString *casts = @"主演：";
    for (NSDictionary *dict in movie.casts) {
        NSString *castname = dict[@"name"];
        casts = [casts stringByAppendingFormat:@"%@,",castname];
    }
    cell.casts.text = casts;
        
}

複製代碼

參考: 最快讓你上手ReactiveCocoa之基礎篇 最快讓你上手ReactiveCocoa之進階篇 iOS ReactiveCocoa 最全經常使用API整理（可作爲手冊查詢） ReactiveCocoa 官方GitHub ReactiveCocoa v2.5 源碼解析之架構總覽