iOS使用观察者模式实现推送消息模块化

背景

前段时间作了一些项目解耦重构和一些组件化的工做，推送是不少app种涉及到的应用场景，因此把推送模块作了一些重构的工做，让推送模块可以独立于业务适用于各类的业务场景。

本文的代码连接：PTNotificationManager

分析

推送消息模块和其余模块从技术角度来看是属于同一级别的模块，推送消息模块为了可以和其余业务组件之间既有通讯又能解耦，这复合设计中的控制反转原则，依赖的双方依赖于对方的抽象而不依赖于具体的实现，观察者模式就是一种典型的控制反转场景，观察者模式很适合推送模块的独立和解耦。

实现

观察者模式简析

观察者模式类图

这是一个简单的观察者的类图结构

• 抽象接口 Subject 有一个注册观察者的方法
• 抽象接口 Observer 有一个获取 Subject 数据更新的方法
• Subject 和 Observer 具体的子类重写对应的方法，处理数据
• 有新的消息，ConcreateSubject 会把消息发送给已注册的ConcreateObserver， ConcreateObserver 负责接收消息进行处理

代码实现

抽象接口

OC接口是使用 protocol 实现的，定义观察者（Observer）和被观察主题（Subject）以下：

@protocol PTNotificationObservable;

@protocol PTNotificationObserver <NSObject>

- (void)update:(id<PTNotificationObservable>)sender data:(id)data;

@end


@protocol PTNotificationObservable <NSObject>

- (void)addObserver:(id<PTNotificationObserver>)observer;

@end
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具体实现

推送模块管理类对应的是被观察主题（Subject），定义了以下接口：

• APP启动，初始化推送配置
• 处理注册Token
• 处理接收消息
• 添加观察者

头文件以下：

#import <Foundation/Foundation.h>
#import "PTNotificationProtocllDefine.h"

#undef AS_SINGLETON
#define AS_SINGLETON \
+ (instancetype)sharedInstance;

#undef DEF_SINGLETON
#define DEF_SINGLETON \
+ (instancetype)sharedInstance{ \
static dispatch_once_t once; \
static id __singleton__; \
dispatch_once( &once, ^{ __singleton__ = [[self alloc] init]; } ); \
return __singleton__; \
} \


@interface PTNotificationManager : NSObject <PTNotificationObservable>

AS_SINGLETON

// 处理APP启动，配置推送
- (void)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions;
// 处理注册Token
- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken;
// 处理接收消息
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo;

// 添加观察者
- (void)addObserver:(id<PTNotificationObserver>)observer;

- (void)testSendNotification;

@end
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集成的是第三方的友盟消息推送，全部里面包含了友盟一些API的使用。
实现文件：

#import "PTNotificationManager.h"
#import "UMessage.h"
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 100000
#import <UserNotifications/UserNotifications.h>
#endif

#define UMengAppKey @"xxxxx"

@interface PTNotificationManager ()<UNUserNotificationCenterDelegate>
@property (nonatomic, strong) NSPointerArray* observers;
@end

@implementation PTNotificationManager

DEF_SINGLETON

- (void)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    //设置 AppKey 及 LaunchOptions
    [UMessage startWithAppkey:UMengAppKey launchOptions:launchOptions];
    //注册通知
    [UMessage registerForRemoteNotifications];
    
    //iOS10必须加下面这段代码。
    if ([[[UIDevice currentDevice] systemVersion]intValue] >= 10) {
        UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter];
        center.delegate=self;
        UNAuthorizationOptions types10=UNAuthorizationOptionBadge|UNAuthorizationOptionAlert|UNAuthorizationOptionSound;
        [center requestAuthorizationWithOptions:types10 completionHandler:^(BOOL granted, NSError * _Nullable error) {
            if (granted) {
                //点击容许
            } else {
                //点击不容许
            }
        }];
    }
    
    //若是你指望使用交互式(只有iOS 8.0及以上有)的通知，请参考下面注释部分的初始化代码
    if (([[[UIDevice currentDevice] systemVersion]intValue]>=8)&&([[[UIDevice currentDevice] systemVersion]intValue]<10)) {

// UIMutableUserNotificationAction *action1 = [[UIMutableUserNotificationAction alloc] init];
// action1.identifier = @"action1_identifier";
// action1.title=@"打开应用";
// action1.activationMode = UIUserNotificationActivationModeForeground;当点击的时候启动程序
//
// UIMutableUserNotificationAction *action2 = [[UIMutableUserNotificationAction alloc] init]; 第二按钮
// action2.identifier = @"action2_identifier";
// action2.title=@"忽略";
// action2.activationMode = UIUserNotificationActivationModeBackground;当点击的时候不启动程序，在后台处理
// action2.authenticationRequired = YES;须要解锁才能处理，若是action.activationMode = UIUserNotificationActivationModeForeground;则这个属性被忽略；
// action2.destructive = YES;
// UIMutableUserNotificationCategory *actionCategory1 = [[UIMutableUserNotificationCategory alloc] init];
// actionCategory1.identifier = @"category1";这组动做的惟一标示
// [actionCategory1 setActions:@[action1,action2] forContext:(UIUserNotificationActionContextDefault)];
// NSSet *categories = [NSSet setWithObjects:actionCategory1, nil];
// [UMessage registerForRemoteNotifications:categories];
    }
    //若是要在iOS10显示交互式的通知，必须注意实现如下代码
    if ([[[UIDevice currentDevice] systemVersion]intValue]>=10) {

// UNNotificationAction *action1_ios10 = [UNNotificationAction actionWithIdentifier:@"action1_ios10_identifier" title:@"打开应用" options:UNNotificationActionOptionForeground];
// UNNotificationAction *action2_ios10 = [UNNotificationAction actionWithIdentifier:@"action2_ios10_identifier" title:@"忽略" options:UNNotificationActionOptionForeground];
        //UNNotificationCategoryOptionNone
        //UNNotificationCategoryOptionCustomDismissAction 清除通知被触发会走通知的代理方法
        //UNNotificationCategoryOptionAllowInCarPlay 适用于行车模式
// UNNotificationCategory *category1_ios10 = [UNNotificationCategory categoryWithIdentifier:@"category101" actions:@[action1_ios10,action2_ios10] intentIdentifiers:@[] options:UNNotificationCategoryOptionCustomDismissAction];
// NSSet *categories_ios10 = [NSSet setWithObjects:category1_ios10, nil];
// UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter];
// [center setNotificationCategories:categories_ios10];

    }
    
    //若是对角标，文字和声音的取舍，请用下面的方法
    //UIRemoteNotificationType types7 = UIRemoteNotificationTypeBadge|UIRemoteNotificationTypeAlert|UIRemoteNotificationTypeSound;
    //UIUserNotificationType types8 = UIUserNotificationTypeAlert|UIUserNotificationTypeSound|UIUserNotificationTypeBadge;
    //[UMessage registerForRemoteNotifications:categories withTypesForIos7:types7 withTypesForIos8:types8];

    //for log
    [UMessage setLogEnabled:YES];
    
    // 应用从通知启动
    NSDictionary* userInfo = [launchOptions objectForKey:UIApplicationLaunchOptionsRemoteNotificationKey];
    if (userInfo) {
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            [self handleNotificationUserInfo:userInfo];
        });
    }
}

- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken {
    //1.2.7版本开始不须要用户再手动注册devicetoken，SDK会自动注册
    // [UMessage registerDeviceToken:deviceToken];
    
    NSString* tokenString = [self stringDevicetoken:deviceToken];
    NSLog(@"==tokenString = %@", tokenString);
    printf([[NSString stringWithFormat:@"\n\ntokenString = %@\n\n", tokenString] UTF8String]);
}

/** - (void)application:(UIApplication *)application didFailToRegisterForRemoteNotificationsWithError:(NSError *)error { //若是注册不成功，打印错误信息，能够在网上找到对应的解决方案 //1.2.7版本开始自动捕获这个方法，log以application:didFailToRegisterForRemoteNotificationsWithError开头 } */

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {
    [[NSNotificationCenter defaultCenter] postNotificationName:@"userInfoNotification" object:self userInfo:@{@"userinfo":[NSString stringWithFormat:@"%@",userInfo]}];
    //关闭友盟自带的弹出框
    [UMessage setAutoAlert:NO];
    [UMessage didReceiveRemoteNotification:userInfo];
    if (application.applicationState != UIApplicationStateActive) {
        [self handleNotificationUserInfo:userInfo];
    }
}

// 添加观察者
- (void)addObserver:(id<PTNotificationObserver>)observer {
    [self.observers addPointer:(__bridge void * _Nullable)(observer)];
}

- (void)testSendNotification {
    [self handleNotificationUserInfo:@{@"kkk": @"kkk"}];
}

- (void)handleNotificationUserInfo:(NSDictionary *)userInfo {
    for (id<PTNotificationObserver> observer in self.observers.allObjects) {
        [observer update:self data:userInfo];
    }
}

#pragma mark - ......::::::: UNUserNotificationCenterDelegate :::::::......

//iOS10新增：处理前台收到通知的代理方法
-(void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions))completionHandler {
    NSDictionary * userInfo = notification.request.content.userInfo;
    if([notification.request.trigger isKindOfClass:[UNPushNotificationTrigger class]]) {
        //应用处于前台时的远程推送接受
        //必须加这句代码
        [UMessage setAutoAlert:NO];
        [UMessage didReceiveRemoteNotification:userInfo];
    }else{
        //应用处于前台时的本地推送接受
    }
}

//iOS10新增：处理后台点击通知的代理方法
- (void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(nonnull void (^)(void))completionHandler {
    NSDictionary * userInfo = response.notification.request.content.userInfo;
    if([response.notification.request.trigger isKindOfClass:[UNPushNotificationTrigger class]]) {
        //应用处于后台时的远程推送接受
        //必须加这句代码
        [UMessage didReceiveRemoteNotification:userInfo];
        [self handleNotificationUserInfo:userInfo];
    }else{
        //应用处于后台时的本地推送接受
    }
}


#pragma mark - ......::::::: Helper :::::::......

-(NSString *)stringDevicetoken:(NSData *)deviceToken {
    NSString *token = [deviceToken description];
    NSString *pushToken = [[[token stringByReplacingOccurrencesOfString:@"<"withString:@""] stringByReplacingOccurrencesOfString:@">"withString:@""] stringByReplacingOccurrencesOfString:@" " withString:@""];
    return pushToken;
}


#pragma mark - ......::::::: Lazy Load :::::::......

- (NSPointerArray *)observers {
    if (nil == _observers) {
        _observers = [NSPointerArray weakObjectsPointerArray];
    }
    return _observers;
}

@end
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使用方法：

• ViewController 实现了 PTNotificationObserver Protocol 做为观察者
• 重写 - (void)update:(id<PTNotificationObservable>)sender data:(id)data 方法打印接收到的消息
• 在 - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event 模拟让消息模块发送消息

@interface PTViewController () <PTNotificationObserver>

@end

@implementation PTViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[PTNotificationManager sharedInstance] addObserver:self];

}

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


// 接收到消息
- (void)update:(id<PTNotificationObservable>)sender data:(id)data {
    NSLog(@"%@", data);
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    [[PTNotificationManager sharedInstance] testSendNotification];
}
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使用cocopods集成

使用 pod lib create 命令建立私有库

➜  DevPods pod lib create PTNotificationManager
Cloning `https://github.com/CocoaPods/pod-template.git` into `PTNotificationManager`.
Configuring PTNotificationManager template.

------------------------------

To get you started we need to ask a few questions, this should only take a minute.

If this is your first time we recommend running through with the guide: 
 - http://guides.cocoapods.org/making/using-pod-lib-create.html
 ( hold cmd and double click links to open in a browser. )


What language do you want to use?? [ Swift / ObjC ]
 > Objc

Would you like to include a demo application with your library? [ Yes / No ]
 > 
yes
Which testing frameworks will you use? [ Specta / Kiwi / None ]
 > None

Would you like to do view based testing? [ Yes / No ]
 > No

What is your class prefix?
 > PT

Running pod install on your new library.

Analyzing dependencies
Fetching podspec for `PTNotificationManager` from `../`
Downloading dependencies
Installing PTNotificationManager (0.1.0)
Generating Pods project
Integrating client project

[!] Please close any current Xcode sessions and use `PTNotificationManager.xcworkspace` for this project from now on.
Sending stats
Pod installation complete! There is 1 dependency from the Podfile and 1 total pod installed.

[!] Automatically assigning platform ios with version 9.3 on target PTNotificationManager_Example because no platform was specified. Please specify a platform for this target in your Podfile. See `https://guides.cocoapods.org/syntax/podfile.html#platform`.

 Ace! you're ready to go! We will start you off by opening your project in Xcode open 'PTNotificationManager/Example/PTNotificationManager.xcworkspace' To learn more about the template see `https://github.com/CocoaPods/pod-template.git`. To learn more about creating a new pod, see `http://guides.cocoapods.org/making/making-a-cocoapod`. ➜ DevPods 复制代码

修改 PTNotificationManager.podspec 文件以下

Pod::Spec.new do |s|
  s.name             = 'PTNotificationManager'
  s.version          = '0.1.0'
  s.summary          = 'A short description of PTNotificationManager.'
  s.description      = <<-DESC Oh PTNotificationManager DESC

  s.homepage         = 'https://github.com/flypigrmvb/PTNotificationManager'
  s.license          = { :type => 'MIT', :file => 'LICENSE' }
  s.author           = { 'flypigrmvb' => '862709539@qq.com' }
  s.source           = { :git => 'https://github.com/flypigrmvb/PTNotificationManager.git', :tag => s.version.to_s }

  s.ios.deployment_target = '8.0'

  s.source_files = 'PTNotificationManager/Classes/**/*'

  # s.public_header_files = 'Pod/Classes/**/*.h'

    # 添加依赖的系统静态库
    s.libraries = 'xml2', 'z', 'c++', 'stdc++.6', 'sqlite3'
    # 添加系统的farme依赖库
    s.frameworks = 'UIKit', 'MapKit'
    # 添加其余Pod依赖库
    s.dependency 'UMessage'
end
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Example项目的 Podfile 添加以下内容

platform :ios, '8.0'

inhibit_all_warnings!

target 'PTNotificationManager_Example' do
  pod 'PTNotificationManager', :path => '../'
  pod 'UMessage', :podspec => 'https://raw.githubusercontent.com/kkme/UMessage/master/UMessage.podspec'

end
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以上步骤Example项目就能够跑起来了，完成了简单的推送消息模块的组件化和解耦，方便在不一样的业主场景中使用。