iOS插件化架构探索

Posted 2022-01-26 搜狐技术产品

self = [super init];

if (self)

_uriString = [uriString copy];

NSURL *url = [NSURL URLWithString:_uriString];

if (!url || !url.scheme) return nil;

// scheme用来标记动态库协议名
_scheme = url.scheme;

NSRange pathRange = NSMakeRange(_scheme.length + 3, _uriString.length - _scheme.length - 3);

if (url.query)

NSArray *components = [url.query componentsSeparatedByString:@"&"];
NSMutableDictionary *parameters = [NSMutableDictionary dictionaryWithCapacity:0];

for (NSString *item in components)

NSArray *subItems = [item componentsSeparatedByString:@"="];
if (subItems.count >= 2)

parameters[subItems[0]] = subItems[1];



// parameters用来标记动态库初始化参数
_parameters = parameters;

pathRange.length -= (url.query.length + 1);


if (pathRange.length > 0 && pathRange.location < uriString.length)

// resourcePath用来标记动态库路径
_resourcePath = [_uriString substringWithRange:pathRange];



return self;

SVPDispatch主要代码如下：

// 根据URI获取动态库主入口页面
- (id)resourceWithURI:(NSString *)uriString

    if (!uriString || !_bundleProvider) return nil;

    return [self resourceWithObject:[SVPURI URIWithString:uriString]];


- (id)resourceWithObject:(SVPURI *)uri

    if (!uri) return nil;

    id resource = nil;

  	// bundleProvider为SVPRuntime，其实现代理方法返回URI对应的动态库的principalObject
    if (_bundleProvider && [_bundleProvider respondsToSelector:@selector(bundleDelegateWithURI:)])
    
        id<SVPBundleDelegate> delegate = [_bundleProvider bundleDelegateWithURI:uri];
      
      	// delegate为动态库的principalObject，其实现代理方法返回动态库的主入口页面
        if (delegate && [delegate respondsToSelector:@selector(resourceWithURI:)])
        
            resource = [delegate resourceWithURI:uri];
        
    

    return resource;

if (self.status == SVPBundleLoaded) return YES;

self.status = SVPBundleLoading;

// 使用路径获取一个NSBundle对象
self.bundle = [NSBundle bundleWithPath:self.bundlePath];

NSError *error = nil;

if (![self.bundle preflightAndReturnError:&error])

NSLog(@"%@", error);


// 加载NSBundle
if (self.bundle && [self.bundle load])

self.status = SVPBundleLoaded;

// 获取NSBundle的principalObject
self.principalObject = [[[self.bundle principalClass] alloc] init];

if (self.principalObject && [self.principalObject respondsToSelector:@selector(bundleDidLoad)])

[self.principalObject performSelector:@selector(bundleDidLoad)];


else

self.status = SVPBundleLoadFailed;


return self.status == SVPBundleLoaded;

SVPBundleManager主要代码如下：

- (instancetype)init 
    self = [super init];
    if (self) 
      	// 遵循SVPCore的协议
        [SVPAccessor defaultAccessor].bundleProvider = self;
        
      	// 遍历本地文件夹，加载动态库
        _installedBundles = [NSMutableDictionary dictionary];
        NSString *mainPath = [self bundleFolder];
        NSDirectoryEnumerator *directoryEnumerator = [self.fileManager enumeratorAtPath:mainPath];
        for (NSString *path in directoryEnumerator.allObjects) 
            NSString *subPath = [mainPath stringByAppendingPathComponent:path];
            NSArray *dirArray = [self.fileManager contentsOfDirectoryAtPath:subPath error:nil];
            if (dirArray.count > 0) 
                NSString *frameworkName = [dirArray firstObject];
                if ([frameworkName hasSuffix:@".framework"]) 
                    NSString *bundlePath = [subPath stringByAppendingPathComponent:frameworkName];
                    SVPBundle *bundle = [[SVPBundle alloc] initWithBundlePath:bundlePath];
                    
                    NSString *version = @"";
                    NSArray *strArray = [frameworkName componentsSeparatedByString:@"_"];
                    if (strArray.count > 0) 
                        version = [strArray firstObject];
                    
                  	// 动态库标识：版本号+唯一标识
                    NSString *bundleKey = [NSString stringWithFormat:@"%@_%@", version, path];
                    _installedBundles[bundleKey] = bundle;
                
            
        
    
    return self;


#pragma mark - SVPBundleDownloadItemDelegate

// 下载完成，解压下载下来的动态库
- (void)downloadBundleItem:(SVPBundleDownloadItem *)downloadItem finished:(BOOL)success 
    if (success) 
        [self unZipDownloadItem:downloadItem];
     else 
        if (self.finishBlock) 
            self.finishBlock(NO);
            self.finishBlock = nil;
        
    


#pragma mark - SVPBundleProviderDelegate

// 实现SVPCore的协议，返回URI对应的动态库的principalObject
- (id)bundleDelegateWithURI:(SVPURI *)uri 
    if ([uri.scheme isEqual:@"scheme"] && uri.resourcePath.length > 0) 
        SVPBundle *bundle = _installedBundles[uri.resourcePath];
        if (bundle) 
            return bundle.principalObject;
        
    

    return nil;

if ([uri.scheme isEqual:@"scheme"])
if ([uri.resourcePath isEqualToString:@"wechat"])
SVPWechatViewController *wechatVC = [[SVPWechatViewController alloc] initWithParameters:uri.parameters];
return wechatVC;



return nil;

SVPWechatViewController，就是该插件的主入口对象，在此基础上实现插件的独立功能就可以了。

然后，最重要的一步，需要在该动态库的Info.plist文件配置Principal class，这个条目的作用是通过NSBundle的principalClass获取到该对象，如下图将SVPWechatBundleDelegate设置进去之后，加载完成后的Bundle发送principalClass消息，拿到的就是这个对象。由于SVPWechatBundleDelegate实现了SVPBundleDelegate协议的resourceWithURI:方法，就可以将插件的入口控制器返回给调用方。

动态库

之后将该插件的动态库编译后打成压缩包，放到服务器上提供下载链接即可。

NSInteger itemIndex = sender.tag - 1000;
if (itemIndex >= 0 && itemIndex < self.pluginArray.count)
// 点击的插件对应的配置列表信息
PluginItem *pluginItem = [self.pluginArray objectAtIndex:itemIndex];

// 动态库标识：版本号+唯一标识，以实现动态更新的目的
NSString *bundleKey = [NSString stringWithFormat:@"%@_%@", pluginItem.version, pluginItem.identifier];
if (![[SVPBundleManager defaultManager] isInstalledBundleWithBundleKey:bundleKey])

// 本地未加载，先从服务器下载动态库
__weak __typeof(self)weakSelf = self;
__weak __typeof(PluginItem *)weakItem = pluginItem;
__weak __typeof(UIButton *)weakSender = sender;
[[SVPBundleManager defaultManager] downloadItem:[pluginItem toJSONDictionary] finished:^(BOOL success)
__strong __typeof(weakSelf)strongSelf = weakSelf;
__strong __typeof(weakItem)strongItem = weakItem;
__strong __typeof(weakSender)strongSender = weakSender;
if (success)
dispatch_sync(dispatch_get_main_queue(), ^
[strongSelf pushBundleVC:itemIndex];
);
else
// 提示下载失败

dispatch_sync(dispatch_get_main_queue(), ^
[strongSender setTitle:strongItem.name forState:UIControlStateNormal];
);
];
[sender setTitle:@"下载中..." forState:UIControlStateNormal];

else

// 本地已加载，push动态库的主入口页面
[self pushBundleVC:itemIndex];




- (void)pushBundleVC:(NSInteger)index
if (index >= 0 && index < self.pluginArray.count)
PluginItem *pluginItem = [self.pluginArray objectAtIndex:index];
NSString *uriString = [NSString stringWithFormat:@"scheme://%@_%@", pluginItem.version, pluginItem.resource];
UIViewController *vc = [[SVPAccessor defaultAccessor] resourceWithURI:uriString];
if (vc)

[self.navigationController pushViewController:vc animated:YES];

当插件模块需要更新时，只需要修改服务器上的配置列表和插件动态库压缩包，主工程在适当的时机更新本地配置列表，当用户点击该插件功能时，即可根据版本号查找并更新本地动态库，达到动态更新的目的。

＋

注意事项

系统在加载动态库时，会检查Framework的签名，签名中必须包含TeamIdentifier，并且Framework和主App的TeamIdentifier必须一致。

如果不一致，会报下面的错误：

Error loading /path/to/framework: dlopen(/path/to/framework, 265): no suitable image found. Did find:/path/to/framework:code signature 

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