Design Scalable iOS Component Architecture: MGJRouter, CTMediator & More

Introduction

The article provides a comprehensive guide to building a component‑based architecture for iOS projects, focusing on modularization, routing, and dynamic configuration. It analyses three popular solutions—MGJRouter, Protocol‑based routing, and CTMediator—while referencing real‑world implementations from Mogujie, Didi, and Alibaba.

Componentization Overview

Componentization aims to split a large codebase into independent modules (components) that can be developed, tested, and released separately. Each component is managed in its own Git repository and integrated into the main app via CocoaPods, allowing parallel development and reducing merge conflicts.

MGJRouter Scheme

MGJRouter is a lightweight URL‑based router that maps a URL to a block of code. It supports both native and H5 navigation, flexible parameter passing, and optional completion callbacks.

#ifndef UserCenterPublicHeader_h
#define UserCenterPublicHeader_h
/** Jump to user login screen */
static const NSString *CTBUCUserLogin = @"CTB://UserCenter/UserLogin";
static const NSString *CTBUCUserRegister = @"CTB://UserCenter/UserRegister";
static const NSString *CTBUCUserStatus = @"CTB://UserCenter/UserStatus";
#endif

Registration example:

[MGJRouter registerURLPattern:@"CTB://UserCenter/UserLogin" toHandler:^(NSDictionary *routerParameters) {
    UIViewController *loginVC = [[LoginViewController alloc] init];
    loginVC.delegate = routerParameters[CTBUserCenterLoginDelegateKey];
    return loginVC;
}];

Protocol Scheme

The Protocol approach replaces URL‑to‑block mapping with a Class‑to‑Protocol mapping. A central ModuleManager stores a dictionary that maps a protocol to the implementing class, allowing decoupled calls via [[class alloc] init] after runtime lookup.

@protocol MGJUserProtocol <NSObject>
- (NSString *)getUserName;
@end

@interface MGJUserImpl : NSObject <MGJUserProtocol>
@end

@implementation MGJUserImpl
- (NSString *)getUserName { return @"DemoUser"; }
@end

[ModuleManager registerClass:[MGJUserImpl class] forProtocol:@protocol(MGJUserProtocol)];

CTMediator Scheme

CTMediator provides a centralized mediator that forwards calls to target‑action pairs using runtime discovery. It reduces direct dependencies but can become bulky when many services are added.

- (UIViewController *)CTMediator_viewControllerForDetail {
    UIViewController *vc = [self performTarget:@"A" action:@"nativeFetchDetailViewController" params:@{@