iOS组件化方案

一、蘑菇街url-block方案

　　这是蘑菇街中应用的一种页面间调用的方式，通过在启动时注册组件提供的服务，把调用组件使用的url和组件提供的服务block对应起来，保存到内存中。在使用组件的服务时，通过url找到对应的block，然后获取服务。

　　具体实现代码如下：

//Mediator.m 中间件
@implementation Mediator
typedef void (^componentBlock) (id param);
@property (nonatomic, storng) NSMutableDictionary *cache
- (void)registerURLPattern:(NSString *)urlPattern toHandler:(componentBlock)blk {
　　[cache setObject:blk forKey:urlPattern];
}
- (void)openURL:(NSString *)url withParam:(id)param {
　　componentBlock blk = [cache objectForKey:url];
　　if (blk) blk(param);
}
@end

1.先在Mediator中注册url-block

#import "Mediator.h"
#import "WRBookDetailViewController.h"
+ (void)initComponent {
　　[[Mediator sharedInstance] registerURLPattern:@"weread://bookDetail" toHandler:^(NSDictionary *param) {
　　　　WRBookDetailViewController *detailVC = [[WRBookDetailViewController alloc] initWithBookId:param[@"bookId"]];
　　　　[[UIApplication sharedApplication].keyWindow.rootViewController.navigationController pushViewController:detailVC animated:YES];
　　}];
}

2.通过url在中间件中就能找到对应的block，并执行跳转

#import "Mediator.h"
+ (void)gotoDetail:(NSString *)bookId {
　　[[Mediator sharedInstance] openURL:@"weread://bookDetail" withParam:@{@"bookId": bookId}];
}

二、 蘑菇街protocol-class方案

　　针对url-block方案无法传递非正规参数，新增一种protocol-class方案

//ProtocolMediator.m 中间件
@implementation ProtocolMediator
@property (nonatomic, storng) NSMutableDictionary *protocolCache
- (void)registerProtocol:(Protocol *)proto forClass:(Class)cls {
　　NSMutableDictionary *protocolCache;
　　[protocolCache setObject:cls forKey:NSStringFromProtocol(proto)];
}

- (Class)classForProtocol:(Protocol *)proto {
　　return protocolCache[NSStringFromProtocol(proto)];
}
@end

每一个组件都有一个公共Protocol文件，定义了每一个组件对外提供的接口

//ComponentProtocol.h
@protocol BookDetailComponentProtocol <NSObject>
- (UIViewController *)bookDetailController:(NSString *)bookId;
- (UIImage *)coverImageWithBookId:(NSString *)bookId;
@end

@protocol ReviewComponentProtocol <NSObject>
- (UIViewController *)ReviewController:(NSString *)bookId;
@end

//BookDetailComponent 组件
#import "ProtocolMediator.h"
#import "ComponentProtocol.h"
#import "WRBookDetailViewController.h"
+ (void)initComponent{
　　[[ProtocolMediator sharedInstance] registerProtocol:@protocol(BookDetailComponentProtocol) forClass:[self class];
}

- (UIViewController *)bookDetailController:(NSString *)bookId {
　　WRBookDetailViewController *detailVC = [[WRBookDetailViewController alloc] initWithBookId:param[@"bookId"]];
　　return detailVC;
}

- (UIImage *)coverImageWithBookId:(NSString *)bookId {
　　….
}

最后调用者通过 protocol 从 ProtocolMediator 拿到提供这些方法的 Class，再进行调用：

//WRReadingViewController.m 调用者
//ReadingViewController.m
#import "ProtocolMediator.h"
#import "ComponentProtocol.h"
+ (void)gotoDetail:(NSString *)bookId {
　　Class cls = [[ProtocolMediator sharedInstance] classForProtocol:BookDetailComponentProtocol];
　　id bookDetailComponent = [[cls alloc] init];
　　UIViewController *vc = [bookDetailComponent bookDetailController:bookId];
　　[self.navigationController pushViewController:vc animated:YES];
}

三、target-action方案

　　1.先设置一个中间件公共类

@interface CTMediator : NSObject

+ (instancetype)sharedInstance;

// 远程App调用入口
- (id)performActionWithUrl:(NSURL *)url completion:(void(^)(NSDictionary *info))completion;
// 本地组件调用入口
- (id)performTarget:(NSString *)targetName action:(NSString *)actionName params:(NSDictionary *)params shouldCacheTarget:(BOOL)shouldCacheTarget;
- (void)releaseCachedTargetWithTargetName:(NSString *)targetName;

@end

//
//  CTMediator.m
//  CTMediator
//
//  Created by casa on 16/3/13.
//  Copyright © 2016年 casa. All rights reserved.
//

#import "CTMediator.h"

@interface CTMediator ()

@property (nonatomic, strong) NSMutableDictionary *cachedTarget;

@end

@implementation CTMediator

#pragma mark - public methods
+ (instancetype)sharedInstance
{
    static CTMediator *mediator;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        mediator = [[CTMediator alloc] init];
    });
    return mediator;
}

/*
 scheme://[target]/[action]?[params]

 url sample:
 aaa://targetA/actionB?id=1234
 */

- (id)performActionWithUrl:(NSURL *)url completion:(void (^)(NSDictionary *))completion
{
    NSMutableDictionary *params = [[NSMutableDictionary alloc] init];
    NSString *urlString = [url query];
    for (NSString *param in [urlString componentsSeparatedByString:@"&"]) {
        NSArray *elts = [param componentsSeparatedByString:@"="];
        if([elts count] < 2) continue;
        [params setObject:[elts lastObject] forKey:[elts firstObject]];
    }

    // 这里这么写主要是出于安全考虑，防止黑客通过远程方式调用本地模块。这里的做法足以应对绝大多数场景，如果要求更加严苛，也可以做更加复杂的安全逻辑。
    NSString *actionName = [url.path stringByReplacingOccurrencesOfString:@"/" withString:@""];
    if ([actionName hasPrefix:@"native"]) {
        return @(NO);
    }

    // 这个demo针对URL的路由处理非常简单，就只是取对应的target名字和method名字，但这已经足以应对绝大部份需求。如果需要拓展，可以在这个方法调用之前加入完整的路由逻辑
    id result = [self performTarget:url.host action:actionName params:params shouldCacheTarget:NO];
    if (completion) {
        if (result) {
            completion(@{@"result":result});
        } else {
            completion(nil);
        }
    }
    return result;
}

- (id)performTarget:(NSString *)targetName action:(NSString *)actionName params:(NSDictionary *)params shouldCacheTarget:(BOOL)shouldCacheTarget
{

    NSString *targetClassString = [NSString stringWithFormat:@"Target_%@", targetName];
    NSString *actionString = [NSString stringWithFormat:@"Action_%@:", actionName];

    id target = self.cachedTarget[targetClassString];
    if (target == nil) {
        Class targetClass = NSClassFromString(targetClassString);
        target = [[targetClass alloc] init];
    }

    SEL action = NSSelectorFromString(actionString);

    if (target == nil) {
        // 这里是处理无响应请求的地方之一，这个demo做得比较简单，如果没有可以响应的target，就直接return了。实际开发过程中是可以事先给一个固定的target专门用于在这个时候顶上，然后处理这种请求的
        return nil;
    }

    if (shouldCacheTarget) {
        self.cachedTarget[targetClassString] = target;
    }

    if ([target respondsToSelector:action]) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
        return [target performSelector:action withObject:params];
#pragma clang diagnostic pop
    } else {
        // 这里是处理无响应请求的地方，如果无响应，则尝试调用对应target的notFound方法统一处理
        SEL action = NSSelectorFromString(@"notFound:");
        if ([target respondsToSelector:action]) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
            return [target performSelector:action withObject:params];
#pragma clang diagnostic pop
        } else {
            // 这里也是处理无响应请求的地方，在notFound都没有的时候，这个demo是直接return了。实际开发过程中，可以用前面提到的固定的target顶上的。
            [self.cachedTarget removeObjectForKey:targetClassString];
            return nil;
        }
    }
}

- (void)releaseCachedTargetWithTargetName:(NSString *)targetName
{
    NSString *targetClassString = [NSString stringWithFormat:@"Target_%@", targetName];
    [self.cachedTarget removeObjectForKey:targetClassString];
}

#pragma mark - getters and setters
- (NSMutableDictionary *)cachedTarget
{
    if (_cachedTarget == nil) {
        _cachedTarget = [[NSMutableDictionary alloc] init];
    }
    return _cachedTarget;
}

@end

2.每个组件创建一个Category，在其中实现当前组件的跳转实现

#import <CTMediator/CTMediator.h>
#import <UIKit/UIKit.h>

@interface CTMediator (TAConfirmOrder)

- (UIViewController *)confirmOrderViewControllerWithGoodsId:(NSString *)goodsId goodsName:(NSString *)goodsName ConfirmComplete:(dispatch_block_t)confirmComplete;

@end

#import "CTMediator+TAConfirmOrder.h"

@implementation CTMediator (TAConfirmOrder)

- (UIViewController *)confirmOrderViewControllerWithGoodsId:(NSString *)goodsId goodsName:(NSString *)goodsName ConfirmComplete:(dispatch_block_t)confirmComplete
{
    NSMutableDictionary *params = [[NSMutableDictionary alloc] init];
    params[@"goodsId"] = goodsId;
    params[@"goodsName"] = goodsName;
    params[@"completeBlock"] = confirmComplete;
    return [self performTarget:@"TAConfirmOrder" action:@"ConfirmOrderViewController" params:params shouldCacheTarget:NO];
}

@end

3.通过中间件调用

UIViewController *confirmOrderVC = [[CTMediator sharedInstance] confirmOrderViewControllerWithGoodsId:self.goodsId  goodsName:self.goodsName  ConfirmComplete:^{

//...

}];