Hybrid APP基础篇(五)->JSBridge实现示例

说明

JSBridge实现示例

目录

• 前言
  • 参考来源
  • 楔子
• JS实现部分
  • 说明
  • 实现
• Android实现部分
  • 说明
  • JSBridge类 实现
  • Callback类 实现
  • Webview容器关键代码 实现
  • API 类实现
• iOS实现部分
  • 说明
  • WebViewJavascriptBridgeBase 实现
  • WebViewJavascriptBridge 实现
  • Webview容器关键代码 实现

前言

参考来源

前人栽树,后台乘凉,本文参考了以下来源

• Hybrid APP架构设计思路
• marcuswestin/WebViewJavascriptBridge

楔子

本文介绍JSBridge的完整实现,包括JS部分,Android原生,iOS原生部分

JS实现部分

说明

这是一份剔除了业务之后的JSbridge实现代码(JS部分)。JS实现代码就一套

实现

实现代码如下

(function() {
	(function() {
		var hasOwnProperty = Object.prototype.hasOwnProperty;
		var JSBridge = window.JSBridge || (window.JSBridge = {});
		//jsbridge协议定义的名称
		var CUSTOM_PROTOCOL_SCHEME = 'CustomJSBridge';
		//最外层的api名称
		var API_Name = 'namespace_bridge';
		//进行url scheme传值的iframe
		var messagingIframe = document.createElement('iframe');
		messagingIframe.style.display = 'none';
		messagingIframe.src = CUSTOM_PROTOCOL_SCHEME + '://' + API_Name;
		document.documentElement.appendChild(messagingIframe);

		//定义的回调函数集合,在原生调用完对应的方法后,会执行对应的回调函数id
		var responseCallbacks = {};
		//唯一id,用来确保每一个回调函数的唯一性
		var uniqueId = 1;
		//本地注册的方法集合,原生只能调用本地注册的方法,否则会提示错误
		var messageHandlers = {};
		//当原生调用H5注册的方法时,通过回调来调用(也就是变为了异步执行,加强安全性)
		var dispatchMessagesWithTimeoutSafety = true;
		//本地运行中的方法队列
		var sendMessageQueue = [];

		//实际暴露给原生调用的对象
		var Inner = {
			/**
			 * @description 注册本地JS方法通过JSBridge给原生调用
			 * 我们规定,原生必须通过JSBridge来调用H5的方法
			 * 注意,这里一般对本地函数有一些要求,要求第一个参数是data,第二个参数是callback
			 * @param {String} handlerName 方法名
			 * @param {Function} handler 对应的方法
			 */
			registerHandler: function(handlerName, handler) {
				messageHandlers[handlerName] = handler;
			},
			/**
			 * @description 调用原生开放的方法
			 * @param {String} handlerName 方法名
			 * @param {JSON} data 参数
			 * @param {Function} callback 回调函数
			 */
			callHandler: function(handlerName, data, callback) {
				//如果没有 data
				if(arguments.length == 3 && typeof data == 'function') {
					callback = data;
					data = null;
				}
				_doSend({
					handlerName: handlerName,
					data: data
				}, callback);
			},
			/**
			 * iOS专用
			 * @description 当本地调用了callHandler之后,实际是调用了通用的scheme,通知原生
			 * 然后原生通过调用这个方法来获知当前正在调用的方法队列
			 */
			_fetchQueue: function() {
				var messageQueueString = JSON.stringify(sendMessageQueue);
				sendMessageQueue = [];
				return messageQueueString;
			},
			/**
			 * @description 原生调用H5页面注册的方法,或者调用回调方法
			 * @param {String} messageJSON 对应的方法的详情,需要手动转为json
			 */
			_handleMessageFromNative: function(messageJSON) {
				setTimeout(_doDispatchMessageFromNative);
				/**
				 * @description 处理原生过来的方法
				 */
				function _doDispatchMessageFromNative() {
					var message;
					try {
						message = JSON.parse(messageJSON);
					} catch(e) {
						//TODO handle the exception
						console.error("原生调用H5方法出错,传入参数错误");
						return;
					}

					//回调函数
					var responseCallback;
					if(message.responseId) {
						//这里规定,原生执行方法完毕后准备通知h5执行回调时,回调函数id是responseId
						responseCallback = responseCallbacks[message.responseId];
						if(!responseCallback) {
							return;
						}
						//执行本地的回调函数
						responseCallback(message.responseData);
						delete responseCallbacks[message.responseId];
					} else {
						//否则,代表原生主动执行h5本地的函数
						if(message.callbackId) {
							//先判断是否需要本地H5执行回调函数
							//如果需要本地函数执行回调通知原生,那么在本地注册回调函数,然后再调用原生
							//回调数据有h5函数执行完毕后传入
							var callbackResponseId = message.callbackId;
							responseCallback = function(responseData) {
								//默认是调用EJS api上面的函数
								//然后接下来原生知道scheme被调用后主动获取这个信息
								//所以原生这时候应该会进行判断,判断对于函数是否成功执行,并接收数据
								//这时候通讯完毕(由于h5不会对回调添加回调,所以接下来没有通信了)
								_doSend({
									handlerName: message.handlerName,
									responseId: callbackResponseId,
									responseData: responseData
								});
							};
						}

						//从本地注册的函数中获取
						var handler = messageHandlers[message.handlerName];
						if(!handler) {
							//本地没有注册这个函数
						} else {
							//执行本地函数,按照要求传入数据和回调
							handler(message.data, responseCallback);
						}
					}
				}
			}

		};
		/**
		 * @description JS调用原生方法前,会先send到这里进行处理
		 * @param {JSON} message 调用的方法详情,包括方法名,参数
		 * @param {Function} responseCallback 调用完方法后的回调
		 */
		function _doSend(message, responseCallback) {
			if(responseCallback) {
				//取到一个唯一的callbackid
				var callbackId = Util.getCallbackId();
				//回调函数添加到集合中
				responseCallbacks[callbackId] = responseCallback;
				//方法的详情添加回调函数的关键标识
				message['callbackId'] = callbackId;
			}
			var uri;
			//android中,可以通过onJsPrompt或者截取Url访问都行
			var ua = navigator.userAgent;
			if(ua.match(/(iPhone\sOS)\s([\d_]+)/)||ua.match(/(iPad).*OS\s([\d_]+)/)) {
				//ios中,通过截取客户端url访问
				//因为ios可以不暴露scheme,而是由原生手动获取
				//正在调用的方法详情添加进入消息队列中,原生会主动获取
				sendMessageQueue.push(message);
				uri = Util.getUri();
			}else{
				//android中兼容处理,将所有的参数一起拼接到url中
				uri = Util.getUri(message);
			}
			//获取 触发方法的url scheme
			//采用iframe跳转scheme的方法
			messagingIframe.src = uri;
		}

		var Util = {
			getCallbackId: function() {
				//如果无法解析端口,可以换为Math.floor(Math.random() * (1 << 30));
				return 'cb_' + (uniqueId++) + '_' + new Date().getTime();
			},
			//获取url scheme
			//第二个参数是兼容android中的做法
			//android中由于原生不能获取JS函数的返回值,所以得通过协议传输
			getUri: function(message) {
				var uri = CUSTOM_PROTOCOL_SCHEME + '://' + API_Name;
				if(message) {
					//回调id作为端口存在
					var callbackId, method, params;
					if(message.callbackId) {
						//第一种:h5主动调用原生
						callbackId = message.callbackId;
						method = message.handlerName;
						params = message.data;
					} else if(message.responseId) {
						//第二种:原生调用h5后,h5回调
						//这种情况下需要原生自行分析传过去的port是否是它定义的回调
						callbackId = message.responseId;
						method = message.handlerName;
						params = message.responseData;
					}
					//参数转为字符串
					params = this.getParam(params);
					//uri 补充
					uri += ':' + callbackId + '/' + method + '?' + params;
				}

				return uri;
			},
			getParam: function(obj) {
				if(obj && typeof obj === 'object') {
					return JSON.stringify(obj);
				} else {
					return obj || '';
				}
			}
		};
		for(var key in Inner) {
			if(!hasOwnProperty.call(JSBridge, key)) {
				JSBridge[key] = Inner[key];
			}
		}

	})();

	//注册一个测试函数
	JSBridge.registerHandler('testH5Func', function(data, callback) {
		alert('测试函数接收到数据:' + JSON.stringify(data));
		callback && callback('测试回传数据...');
	});
	/*
	 ***************************API********************************************
	 * 开放给外界调用的api
	 * */
	window.jsapi = {};
	/**
	 ***app 模块
	 * 一些特殊操作
	 */
	jsapi.app = {
		/**
		 * @description 测试函数
		 */
		testNativeFunc: function() {
			//调用一个测试函数
			JSBridge.callHandler('testNativeFunc', {}, function(res) {
				callback && callback(res);
			});
		}
	};
})();
			

Android实现部分

说明

这是Android原生中配套的JSBridge实现代码。Android的实现相对比JS复杂,包括多个部分

JSBridge类实现

实现代码如下

public class JSBridge {
    private static Map<String, HashMap<String, Method>> exposedMethods = new HashMap<>();

	//原生注册API方法
    public static void register(String exposedName, Class<? extends IBridge> clazz) {
        if (!exposedMethods.containsKey(exposedName)) {
            try {
                exposedMethods.put(exposedName, getAllMethod(clazz));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

	//得到所有的注册方法
    private static HashMap<String, Method> getAllMethod(Class injectedCls) throws Exception {
        HashMap<String, Method> mMethodsMap = new HashMap<>();
        Method[] methods = injectedCls.getDeclaredMethods();
        for (Method method : methods) {
            String name;
            if (method.getModifiers() != (Modifier.PUBLIC | Modifier.STATIC) || (name = method.getName()) == null) {
                continue;
            }
            Class[] parameters = method.getParameterTypes();
            if (null != parameters && parameters.length == 4) {
                if (parameters[0] == BaseWebLoader.class && parameters[1] == WebView.class && parameters[2] == JSONObject.class && parameters[3] == Callback.class) {
                    mMethodsMap.put(name, method);
                }
            }
        }
        return mMethodsMap;
    }

	//调用Hava中的方法
	//其中BaseWebLoader是JSBridge的webview容器(二次封装)
	//执行完方法后,如果又回到,自动就会调用
    public static String callJava(BaseWebLoader webLoader,WebView webView, String uriString) {
        String methodName = "";
        String className = "";
        String param = "{}";
        String port = "";
        if (!TextUtils.isEmpty(uriString) && uriString.startsWith("EpointJSBridge")) {
            Uri uri = Uri.parse(uriString);
            className = uri.getHost();
            param = uri.getQuery();
            port = uri.getPort() + "";
            String path = uri.getPath();
            if (!TextUtils.isEmpty(path)) {
                methodName = path.replace("/", "");
            }
        }

        if (exposedMethods.containsKey(className)) {
            HashMap<String, Method> methodHashMap = exposedMethods.get(className);

            if (methodHashMap != null && methodHashMap.size() != 0 && methodHashMap.containsKey(methodName)) {
                Method method = methodHashMap.get(methodName);
                if (method != null) {
                    try {
                        method.invoke(null,webLoader, webView, new JSONObject(param), new Callback(webView, port));
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return null;
    }
}
			

这个类的作用是原生定义一些暴露的api

Callback类实现

实现代码如下

public class Callback {
    private static Handler mHandler = new Handler(Looper.getMainLooper());
    private static final String CALLBACK_JS_FORMAT = "javascript:JSBridge._handleMessageFromNative(%s);";
    private String mPort;
    private WeakReference<WebView> mWebViewRef;

    public Callback(WebView view, String port) {
        mWebViewRef = new WeakReference<>(view);
        mPort = port;
    }

    public void apply(JSONObject jsonObject) throws JSONException {
        JSONObject object = new JSONObject();
        object.put("responseId", mPort);
        object.putOpt("responseData", jsonObject);
        final String execJs = String.format(CALLBACK_JS_FORMAT, String.valueOf(object));
        //如果activity已经关闭则不回调
        if (mWebViewRef != null && mWebViewRef.get() != null && !((BaseWebLoader) mWebViewRef.get().getContext()).getActivity().isFinishing()) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    mWebViewRef.get().loadUrl(execJs);
                }
            });
        }
    }
}
			

这个类的作用是,定义原生中的回调函数

Webview容器关键代码实现

实现代码如下

注册api方法

//定义api集合
JSBridge.register("namespace_bridge",BridgeImpl.class);
			

捕获url scheme并执行方法的代码

public boolean shouldOverrideUrlLoading(WebView view, String url){
	//读取到url后通过callJava分析调用
	JSBridge.callJava(BaseWebLoader.this,view,url);

	//如果返回false，则WebView处理链接url，如果返回true，代表WebView根据程序来执行url
	return true;
}

里面的关键代码是注册函数,捕获url,执行方法等

API 类实现

实现代码如下

public class BridgeImpl implements IBridge {
	/**
     * 测试原生方法
     */
    public static void testNativeFunc(final BaseWebLoader webLoader, WebView wv, JSONObject param, final Callback callback) {
       //可以这样获取参数 param.optString(键值);
        //在一个新的线程内执行
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    //执行一些自己的内容
                    JSONObject object = new JSONObject();
                    //添加测试信息
                    object.put("test", "test");
                    //执行回调
                    callback.apply(getJSONObject(1, "", object));
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}
			

这个类是一些api的具体实现,webview里面就是注册了这些对应的api

iOS实现部分

说明

这是iOS原生中配套的JSBridge实现代码。iOS中代码是基于UIWebview的,来源于一个github上的开源项目,地址 marcuswestin/WebViewJavascriptBridge

WebViewJavascriptBridgeBase 实现

实现代码如下

@implementation WebViewJavascriptBridgeBase {
    __weak id _webViewDelegate;
    long _uniqueId;
}

static bool logging = false;
static int logMaxLength = 500;

+ (void)enableLogging { logging = true; }
+ (void)setLogMaxLength:(int)length { logMaxLength = length;}

-(id)init {
    self = [super init];
    self.messageHandlers = [NSMutableDictionary dictionary];
    self.startupMessageQueue = [NSMutableArray array];
    self.responseCallbacks = [NSMutableDictionary dictionary];
    _uniqueId = 0;
    return(self);
}

- (void)dealloc {
    self.startupMessageQueue = nil;
    self.responseCallbacks = nil;
    self.messageHandlers = nil;
}

- (void)reset {
    self.startupMessageQueue = [NSMutableArray array];
    self.responseCallbacks = [NSMutableDictionary dictionary];
    _uniqueId = 0;
}

- (void)sendData:(id)data responseCallback:(WVJBResponseCallback)responseCallback handlerName:(NSString*)handlerName {
    NSMutableDictionary* message = [NSMutableDictionary dictionary];

    if (data) {
        message[@"data"] = data;
    }

    if (responseCallback) {
        NSString* callbackId = [NSString stringWithFormat:@"objc_cb_%ld", ++_uniqueId];
        self.responseCallbacks[callbackId] = [responseCallback copy];
        message[@"callbackId"] = callbackId;
    }

    if (handlerName) {
        message[@"handlerName"] = handlerName;
    }
    [self _queueMessage:message];
}

- (void)flushMessageQueue:(NSString *)messageQueueString{
    if (messageQueueString == nil || messageQueueString.length == 0) {
        NSLog(@"WebViewJavascriptBridge: WARNING: ObjC got nil while fetching the message queue JSON from webview. This can happen if the WebViewJavascriptBridge JS is not currently present in the webview, e.g if the webview just loaded a new page.");
        return;
    }

    id messages = [self _deserializeMessageJSON:messageQueueString];
    for (WVJBMessage* message in messages) {
        if (![message isKindOfClass:[WVJBMessage class]]) {
            NSLog(@"WebViewJavascriptBridge: WARNING: Invalid %@ received: %@", [message class], message);
            continue;
        }
        [self _log:@"RCVD" json:message];

        NSString* responseId = message[@"responseId"];
        if (responseId) {
            WVJBResponseCallback responseCallback = _responseCallbacks[responseId];
            responseCallback(message[@"responseData"]);
            [self.responseCallbacks removeObjectForKey:responseId];
        } else {
            WVJBResponseCallback responseCallback = NULL;
            NSString* callbackId = message[@"callbackId"];
            if (callbackId) {
                responseCallback = ^(id responseData) {
                    if (responseData == nil) {
                        responseData = [NSNull null];
                    }

                    WVJBMessage* msg = @{ @"responseId":callbackId, @"responseData":responseData };
                    [self _queueMessage:msg];
                };
            } else {
                responseCallback = ^(id ignoreResponseData) {
                    // Do nothing
                };
            }

            WVJBHandler handler = self.messageHandlers[message[@"handlerName"]];

            if (!handler) {
                NSLog(@"WVJBNoHandlerException, No handler for message from JS: %@", message);
                continue;
            }

            handler(message[@"data"], responseCallback);
        }
    }
}

/*这段代码在本文中没有用到
 * 因为再原项目中,JSBridge的js库是放在iOS本地沙盒中的,所以才需要手动注入
 * 但是本文中的示例,JSBridge是直接在Html中引用的,所以无需注入
- (void)injectJavascriptFile {
    NSString *js = WebViewJavascriptBridge_js();
    [self _evaluateJavascript:js];
    if (self.startupMessageQueue) {
        NSArray* queue = self.startupMessageQueue;
        self.startupMessageQueue = nil;
        for (id queuedMessage in queue) {
            [self _dispatchMessage:queuedMessage];
        }
    }
}
*/
-(BOOL)isCorrectProcotocolScheme:(NSURL*)url {
    if([[url scheme] isEqualToString:kCustomProtocolScheme]){
        return YES;
    } else {
        return NO;
    }
}

-(BOOL)isQueueMessageURL:(NSURL*)url {
    if([[url host] isEqualToString:kQueueHasMessage]){
        return YES;
    } else {
        return NO;
    }
}

-(BOOL)isBridgeLoadedURL:(NSURL*)url {
    return ([[url scheme] isEqualToString:kCustomProtocolScheme] && [[url host] isEqualToString:kBridgeLoaded]);
}

-(void)logUnkownMessage:(NSURL*)url {
    NSLog(@"WebViewJavascriptBridge: WARNING: Received unknown WebViewJavascriptBridge command %@://%@", kCustomProtocolScheme, [url path]);
}

-(NSString *)webViewJavascriptCheckCommand {
    return @"typeof WebViewJavascriptBridge == \'object\';";
}

-(NSString *)webViewJavascriptFetchQueyCommand {
    return @"JSBridge._fetchQueue();";
}

- (void)disableJavscriptAlertBoxSafetyTimeout {
    [self sendData:nil responseCallback:nil handlerName:@"_disableJavascriptAlertBoxSafetyTimeout"];
}

// Private
// -------------------------------------------

- (void) _evaluateJavascript:(NSString *)javascriptCommand {
    [self.delegate _evaluateJavascript:javascriptCommand];
}

- (void)_queueMessage:(WVJBMessage*)message {
//    if (self.startupMessageQueue) {
//        [self.startupMessageQueue addObject:message];
//    } else {
//        [self _dispatchMessage:message];
//    }
    [self _dispatchMessage:message];
}

- (void)_dispatchMessage:(WVJBMessage*)message {
    NSString *messageJSON = [self _serializeMessage:message pretty:NO];
    [self _log:@"SEND" json:messageJSON];
    messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\\" withString:@"\\\\"];
    messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\"" withString:@"\\\""];
    messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\'" withString:@"\\\'"];
    messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\n" withString:@"\\n"];
    messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\r" withString:@"\\r"];
    messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\f" withString:@"\\f"];
    messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\u2028" withString:@"\\u2028"];
    messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\u2029" withString:@"\\u2029"];

    NSString* javascriptCommand = [NSString stringWithFormat:@"JSBridge._handleMessageFromNative('%@');", messageJSON];
    if ([[NSThread currentThread] isMainThread]) {
        [self _evaluateJavascript:javascriptCommand];

    } else {
        dispatch_sync(dispatch_get_main_queue(), ^{
            [self _evaluateJavascript:javascriptCommand];
        });
    }
}

- (NSString *)_serializeMessage:(id)message pretty:(BOOL)pretty{
    return [[NSString alloc] initWithData:[NSJSONSerialization dataWithJSONObject:message options:(NSJSONWritingOptions)(pretty ? NSJSONWritingPrettyPrinted : 0) error:nil] encoding:NSUTF8StringEncoding];
}

- (NSArray*)_deserializeMessageJSON:(NSString *)messageJSON {
    return [NSJSONSerialization JSONObjectWithData:[messageJSON dataUsingEncoding:NSUTF8StringEncoding] options:NSJSONReadingAllowFragments error:nil];
}

- (void)_log:(NSString *)action json:(id)json {
    if (!logging) { return; }
    if (![json isKindOfClass:[NSString class]]) {
        json = [self _serializeMessage:json pretty:YES];
    }
    if ([json length] > logMaxLength) {
        NSLog(@"WVJB %@: %@ [...]", action, [json substringToIndex:logMaxLength]);
    } else {
        NSLog(@"WVJB %@: %@", action, json);
    }
}

@end

WebViewJavascriptBridgeBase是JSBridge逻辑代码的基础支持,也就是说这里面封装一些基础的代码,供JSBridge内部调用

WebViewJavascriptBridge 实现

实现代码如下

#if __has_feature(objc_arc_weak)
    #define WVJB_WEAK __weak
#else
    #define WVJB_WEAK __unsafe_unretained
#endif

@implementation WebViewJavascriptBridge {
    WVJB_WEAK WVJB_WEBVIEW_TYPE* _webView;
    WVJB_WEAK id _webViewDelegate;
    long _uniqueId;
    WebViewJavascriptBridgeBase *_base;
}

/* API
 *****/

+ (void)enableLogging { [WebViewJavascriptBridgeBase enableLogging]; }
+ (void)setLogMaxLength:(int)length { [WebViewJavascriptBridgeBase setLogMaxLength:length]; }

+ (instancetype)bridgeForWebView:(WVJB_WEBVIEW_TYPE*)webView {
    WebViewJavascriptBridge* bridge = [[self alloc] init];
    [bridge _platformSpecificSetup:webView];
    return bridge;
}

- (void)setWebViewDelegate:(WVJB_WEBVIEW_DELEGATE_TYPE*)webViewDelegate {
    _webViewDelegate = webViewDelegate;
}

- (void)send:(id)data {
    [self send:data responseCallback:nil];
}

- (void)send:(id)data responseCallback:(WVJBResponseCallback)responseCallback {
    [_base sendData:data responseCallback:responseCallback handlerName:nil];
}

- (void)callHandler:(NSString *)handlerName {
    [self callHandler:handlerName data:nil responseCallback:nil];
}

- (void)callHandler:(NSString *)handlerName data:(id)data {
    [self callHandler:handlerName data:data responseCallback:nil];
}

- (void)callHandler:(NSString *)handlerName data:(id)data responseCallback:(WVJBResponseCallback)responseCallback {
    [_base sendData:data responseCallback:responseCallback handlerName:handlerName];
}

- (void)registerHandler:(NSString *)handlerName handler:(WVJBHandler)handler {
    _base.messageHandlers[handlerName] = [handler copy];
}

- (void)disableJavscriptAlertBoxSafetyTimeout {
    [_base disableJavscriptAlertBoxSafetyTimeout];
}

/* Platform agnostic internals
 *****************************/

- (void)dealloc {
    [self _platformSpecificDealloc];
    _base = nil;
    _webView = nil;
    _webViewDelegate = nil;
}

- (NSString*) _evaluateJavascript:(NSString*)javascriptCommand
{
    return [_webView stringByEvaluatingJavaScriptFromString:javascriptCommand];
}

/* Platform specific internals: OSX
 **********************************/
#if defined WVJB_PLATFORM_OSX

- (void) _platformSpecificSetup:(WVJB_WEBVIEW_TYPE*)webView {
    _webView = webView;

    _webView.policyDelegate = self;

    _base = [[WebViewJavascriptBridgeBase alloc] init];
    _base.delegate = self;
}

- (void) _platformSpecificDealloc {
    _webView.policyDelegate = nil;
}

- (void)webView:(WebView *)webView decidePolicyForNavigationAction:(NSDictionary *)actionInformation request:(NSURLRequest *)request frame:(WebFrame *)frame decisionListener:(id)listener
{
    if (webView != _webView) { return; }
    NSURL *url = [request URL];

    if ([_base isCorrectProcotocolScheme:url]) {
        if ([_base isBridgeLoadedURL:url]) {
            [_base injectJavascriptFile];
        } else if ([_base isQueueMessageURL:url]) {
            NSString *messageQueueString = [self _evaluateJavascript:[_base webViewJavascriptFetchQueyCommand]];
            [_base flushMessageQueue:messageQueueString];
        } else {
            [_base logUnkownMessage:url];
        }
        [listener ignore];
    } else if (_webViewDelegate && [_webViewDelegate respondsToSelector:@selector(webView:decidePolicyForNavigationAction:request:frame:decisionListener:)]) {
        [_webViewDelegate webView:webView decidePolicyForNavigationAction:actionInformation request:request frame:frame decisionListener:listener];
    } else {
        [listener use];
    }
}

/* Platform specific internals: iOS
 **********************************/
#elif defined WVJB_PLATFORM_IOS

- (void) _platformSpecificSetup:(WVJB_WEBVIEW_TYPE*)webView {
    _webView = webView;
    _webView.delegate = self;
    _base = [[WebViewJavascriptBridgeBase alloc] init];
    _base.delegate = self;
}

- (void) _platformSpecificDealloc {
    _webView.delegate = nil;
}

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    if (webView != _webView) { return; }

    __strong WVJB_WEBVIEW_DELEGATE_TYPE* strongDelegate = _webViewDelegate;
    if (strongDelegate && [strongDelegate respondsToSelector:@selector(webViewDidFinishLoad:)]) {
        [strongDelegate webViewDidFinishLoad:webView];
    }
}

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
    if (webView != _webView) { return; }

    __strong WVJB_WEBVIEW_DELEGATE_TYPE* strongDelegate = _webViewDelegate;
    if (strongDelegate && [strongDelegate respondsToSelector:@selector(webView:didFailLoadWithError:)]) {
        [strongDelegate webView:webView didFailLoadWithError:error];
    }
}
//捕获url,并进行分析
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
    if (webView != _webView) { return YES; }
    NSURL *url = [request URL];
    __strong WVJB_WEBVIEW_DELEGATE_TYPE* strongDelegate = _webViewDelegate;
    if ([_base isCorrectProcotocolScheme:url]) {
        if ([_base isBridgeLoadedURL:url]) {
            [_base injectJavascriptFile];
        } else if ([_base isQueueMessageURL:url]) {
            NSString *messageQueueString = [self _evaluateJavascript:[_base webViewJavascriptFetchQueyCommand]];
            [_base flushMessageQueue:messageQueueString];
        } else {
            [_base logUnkownMessage:url];
        }
        return NO;
    } else if (strongDelegate && [strongDelegate respondsToSelector:@selector(webView:shouldStartLoadWithRequest:navigationType:)]) {
        return [strongDelegate webView:webView shouldStartLoadWithRequest:request navigationType:navigationType];
    } else {
        return YES;
    }
}

- (void)webViewDidStartLoad:(UIWebView *)webView {
    if (webView != _webView) { return; }

    __strong WVJB_WEBVIEW_DELEGATE_TYPE* strongDelegate = _webViewDelegate;
    if (strongDelegate && [strongDelegate respondsToSelector:@selector(webViewDidStartLoad:)]) {
        [strongDelegate webViewDidStartLoad:webView];
    }
}

#endif

@end

WebViewJavascriptBridge是主要的JSBridge逻辑实现代码

Webview容器关键代码 实现

实现代码如下

建立JSBridge桥梁

- (void)viewDidLoad {

    [super viewDidLoad];
    // 一些其它操作

    // WebViewJavascriptBridge
    // 给webView建立JS和OC的沟通桥梁
    [WebViewJavascriptBridge enableLogging];
    self.bridge = [WebViewJavascriptBridge bridgeForWebView:self.wv];
    [self.bridge setWebViewDelegate:self];
    [self registAPIForJS];
}
			

注册API方法

- (void)registAPIForJS
{
    // 测试原生方法
    [self.bridge registerHandler:@"testNativeFunc" handler:^(id data, WVJBResponseCallback responseCallback) {
        //可以这样获取参数
        NSString *str = data[@"key值"];

       //可以做一些自己的事情
    }];
}
			

捕获url scheme并执行方法的代码

//关键是这句代码
[self.bridge setWebViewDelegate:self];
//然后再WebViewJavascriptBridge里就可以重新shouldStartLoadWithRequest来捕获url了