// 友盟統(tǒng)計

// JPush

// 分享相關(guān)

// 基礎(chǔ)數(shù)據(jù)

// 數(shù)據(jù)庫

// 等等...

無窮無盡的需求堆在Appdelegate中將會不忍直視.

1. 各組件分開引入

關(guān)于組件的拆分，就根據(jù)具體項目進(jìn)行拆分，假如APP被拆分了AModule、BModule絮供、CModule，那么茶敏，應(yīng)該如何引入這些組件呢壤靶？你可能會想到APP的入口AppDelegate。在平時開發(fā)中惊搏，AppDelegate中往往初始化了好多組件贮乳，比如推送、統(tǒng)計等組件恬惯，這樣就會導(dǎo)致AppDelegate的臃腫向拆。

所以，我們可以增加一個ModuleManager 酪耳，專門用來初始化各組件亲铡。

首先增加一個 ModuleProtocol：

#import <Foundation/Foundation.h>
@import UIKit;
@import UserNotifications;

@protocol ModuleProtocol <UIApplicationDelegate, UNUserNotificationCenterDelegate>

@end

我們在ModuleManager中hook住UIApplicationDelegate和 UNUserNotificationCenterDelegate中的方法，使相應(yīng)的組件中實現(xiàn)了對應(yīng)方法葡兑，在相應(yīng)時機(jī)就會調(diào)用組建里的對應(yīng)方法：

#import "ModuleManager.h"
#import "AppDelegate.h"
#import <objc/runtime.h>

#define ALL_MODULE [[ModuleManager sharedInstance] allModules]
#define SWIZZLE_METHOD(m) swizzleMethod(class, @selector(m),@selector(module_##m));

@interface ModuleManager ()

@property (nonatomic, strong) NSMutableArray<id<ModuleProtocol>> *modules;

@end

@implementation ModuleManager

+ (instancetype)sharedInstance {
    static ModuleManager *instance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        instance = [[ModuleManager alloc] init];
    });
    return instance;
}

- (void)loadModulesWithPlistFile:(NSString *)plistFile {
    NSArray *modules = [NSArray arrayWithContentsOfFile:plistFile];
    NSLog(@"%@", modules);
    for (NSString *moduleName in modules) {
        [self addModule:moduleName];
    }
}

- (void)addModule:(NSString *)moduleName {
    Class class = NSClassFromString(moduleName);
    if (class_conformsToProtocol(class, @protocol(ModuleProtocol))) {
        id<ModuleProtocol> module = [[class alloc] init];
        [self.modules addObject:module];
    }
}

- (NSMutableArray<id<ModuleProtocol>> *)modules {
    if (!_modules) {
        _modules = [[NSMutableArray alloc] init];
    }
    return _modules;
}
- (NSArray<id<ModuleProtocol>> *)allModules {
    return self.modules;
}
@end

@implementation AppDelegate (Module)

+ (void)load
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        Class class = [self class];
        SWIZZLE_METHOD(application:willFinishLaunchingWithOptions:);
        SWIZZLE_METHOD(application:didFinishLaunchingWithOptions:);
        ......
    });
}

static inline void swizzleMethod(Class class, SEL originalSelector, SEL swizzledSelector) {
    // the method might not exist in the class, but in its superclass
    Method originalMethod = class_getInstanceMethod(class, originalSelector);
    Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
    
    // class_addMethod will fail if original method already exists
    BOOL didAddMethod = class_addMethod(class, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod));
    
    // the method doesn’t exist and we just added one
    if (didAddMethod) {
        class_replaceMethod(class, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));
    }
    else {
        method_exchangeImplementations(originalMethod, swizzledMethod);
    }
}


- (BOOL)module_application:(UIApplication *)application willFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    BOOL result = [self module_application:application willFinishLaunchingWithOptions:launchOptions];
    for (id<ModuleProtocol> module in ALL_MODULE) {
        if ([module respondsToSelector:_cmd]) {
            [module application:application willFinishLaunchingWithOptions:launchOptions];
        }
    }
    return result;
}

- (BOOL)module_application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    BOOL result = [self module_application:application didFinishLaunchingWithOptions:launchOptions];
    for (id<ModuleProtocol> module in ALL_MODULE) {
        if ([module respondsToSelector:_cmd]) {
            [module application:application didFinishLaunchingWithOptions:launchOptions];
        }
    }
    return result;
}
......

@end

ModuleManager.h:

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

@interface ModuleManager : NSObject

+ (instancetype)sharedInstance;

- (void)loadModulesWithPlistFile:(NSString *)plistFile;

- (NSArray<id<ModuleProtocol>> *)allModules;

@end

之后我們通過一個 ModulesRegister.plist文件管理需要引入的組件：

如上圖奖蔓，假如我們要引入AModule、BModule讹堤、CModule吆鹤，那么這三個Module只需要實現(xiàn)協(xié)議ModuleProtocol，然后實現(xiàn)AppDelegate中對應(yīng)的方法洲守，在對應(yīng)方法中初始化自身即可：
AModule.h:

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

@interface AModule : NSObject<ModuleProtocol>

@end

AModule.m:

#import "AModule.h"

@implementation AModule

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
    //初始化AModule
    return YES;
}
@end

之后在AppDelegate的load方法中通過ModulesRegister.plist引入各組件即可：

@implementation AppDelegate

+ (void)load {
    //load modules
    NSString* plistPath = [[NSBundle mainBundle] pathForResource:@"ModulesRegister" ofType:@"plist"];
    [[ModuleManager sharedInstance] loadModulesWithPlistFile:plistPath];
}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    ......
}
@end

這樣疑务，各組件的開發(fā)者在自己的組件中初始化自己沾凄，其他人需要使用時只需要加入ModulesRegister.plist文件中即可。