OC与H5交互

2017-08-26  本文已影响199人  Aliyunyun

OC与H5交互

一、 方案

I. iOS6的方案

ios6 主要是通过UIWebView来实现交互,可以通过一个第三方库来实现(EasyJSWebView的方法来注入JS代码实现交互)

  1. JS 调用 OC

    • JS端: 通过iframe来实现document.documentElement.appendChild(iframe);
    • APP端:主要是通过UIWebView,实现UIWebView的代理方法,截取Request,来实现JS调用OC的代码,
  2. OC调用JS

- (nullable NSString *)stringByEvaluatingJavaScriptFromString:(NSString *)script;

II. iOS7的方案

ios7 主要是通过UIWebView来加载h5的页面,但是IOS7增加了JavaScriptCore来实现原生和H5的交互

  1. JS 调用OC

    • JS端: 由于OC可以通过JavaScriptCore JSExport向JS端注入OC的对象,所以JS端可以直接调用OC的方法。OCObject.test("parmes")
    • APP端:由于可以通过JSContxt直接注入对象,所以可以直接访问对象的方法
  2. OC 调用JS

- (nullable NSString *)stringByEvaluatingJavaScriptFromString:(NSString *)script;

III. iOS8之后的方案

iOS8之后推荐使用WKWebView,WKWebView 不支持JavaScriptCore, 但是提供了 userContentController WKUserContentController 来实现JS的注入, 主要的方式可以叫做messageHandler

  1. JS 调用 OC

    • JS 端:postMessage window.webkit.messageHandlers.Tips.postMessage('xiao黄');

    • APP端:主要是通过WKWebView的代理,来截取方法和参数, WKScriptMessageHandler

  2. OC调用JS

    - (void)evaluateJavaScript:(NSString *)javaScriptString completionHandler:(void (^ _Nullable)(_Nullable id, NSError * _Nullable error))completionHandler;
    
    
    

二、UIWebView原生方法

I. 设置UIWebView的代理,截取request

JS代码

//这个方法刷新的时候不会导致页面消失
function loadURL(url) {
  var iFrame;
  iFrame = document.createElement("iframe");
  iFrame.setAttribute("src",url);
  iFrame.setAttribute("style","display:none");
  iFrame.setAttribute("height","0px");
  iFrame.setAttribute("weight","0px");
  iFrame.setAttribute("frameborder","0");
  document.body.appendChild(iFrame);

  iFrame.parentNode.removeChild(iFrame);
  iFrame = null;
}

// JQuery 的写法,$() 就是JS的document.getElementById()
$(document).ready(function () {
  console.log("xxxxxxxxx");
  $("#login_btn").click(function () {
    // loadURL 来调用OC的方法
    loadURL("yyHetRequest://scan");
  });
});

OC代码


- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    
    NSLog(@"%@ type ", request.URL.absoluteString);
    NSURL *url = [request URL];
    NSString *scheme = [url scheme];
    if ([scheme isEqualToString:@"yyhetrequest"]) {
        [self handleJSRequest:url];
    }
    return true;
}


- (void)handleJSRequest:(NSURL *)url
{
    NSString *host = [url host];
    if ([host isEqualToString:@"scan"]) {
        [self scanAction];
    }
    
}
 NSString *jsCode = 
                    @"var demoP =  document.getElementById('demo');"
                    @"demoP.innerHTML = 'ios write'";
 [_webView stringByEvaluatingJavaScriptFromString:jsCode];

三、EasyJSWebView的使用和原理

I. EasyJsWebView的库,使用方法

1、APP端

// 创建接口对象
@interface MyJSInterface : NSObject

- (void) test;
- (void) config: (NSString*) param;
- (void) testWithTwoParam: (NSString*) param AndParam2: (NSString*) param2;

- (NSString*) testWithRet;

@end

// 在OC中向JS 注入OC对象
MyJSInterface* interface = [MyJSInterface new];
[self.myWebView addJavascriptInterfaces:interface WithName:@"bindJavaScript"];
[interface release];

2、H5端

//js中调用OC的方法
var appInterfaceNS = 'bindJavaScript'; // app注入接口的命名空间
var __AppInterface = window[appInterfaceNS] || {}; // 接入APP接口

/**
 * 通知app开始初始化
 * @param  {json}     options 配置信息及提交给app的初始化信息
 * @return {Function}         返回值由app决定,该值为非必须值
 */
$this.config = function(options){
    var data = {};
    data = JSON.stringify(options);
    return typeof __AppInterface.config === 'function' && __AppInterface.config(data);
};

II. EasyJsWebView的原理

EasyJS的执行过程主要是两个阶段:

1、注入阶段

注入的代码分为两个部分:

  1. 注入一段JS代码,创建EasyJs对象。

  2. 将OC方法,在JS里面再创建一次,并且保存到JS的一个数组。

注入OC对象的方法

[self.myWebView addJavascriptInterfaces:interface WithName:@"MyJSTest"];

注入源码解析:

EasyJSWebView 包含的函数:

a、 EasyJSWebView的头文件,包含了注入JS的过程和加入OC对象的过程

@interface EasyJSWebView : UIWebView

// All the events will pass through this proxy delegate first
@property (nonatomic, retain) EasyJSWebViewProxyDelegate* proxyDelegate;

- (void) initEasyJS;
- (void) addJavascriptInterfaces:(NSObject*) interface WithName:(NSString*) name;

@end


b、 EasyJSWebViewProxyDelegate 主要来实现UIWebView的代理方法,

EasyJSWebViewProxyDelegate的JS代码, 这段JS代码主要是向H5的JS环境中创建一个叫EasyJS的对象,总共包含4个对象:


window.EasyJS = 
{
__callbacks: {},
//回调数组
invokeCallback: 
    function (cbID, removeAfterExecute)
        {
            var args = Array.prototype.slice.call(arguments);
            args.shift();
            args.shift();
            for (var i = 0, l = args.length; i < l; i++)
            {
                args[i] = decodeURIComponent(args[i]);
            }
            var cb = EasyJS.__callbacks[cbID];
            if (removeAfterExecute)
                {
                    EasyJS.__callbacks[cbID] = undefined;
                }
            return cb.apply(null, args);
        },
//根据OC的函数名来创建JS函数,通过iframe调用OC的UIWevView的delegate
//"- (BOOL)webView: shouldStartLoadWithRequest: navigationType:"
// 规则:ios端拿到字符串后`easy-js:MyJSTest:s%12%cd%12f__cd1234562`
// easy-js 表示js调用OC方法的开头
// MyJSTest 表示OC想JS暴露的对象
// s 表示数组下一位为参数
// f 表示数组下一位为函数,主要f后面跟着的内容是一个key,这个key表示OC对JS的回调,JS会将这项回调保存到
call: 
    function (obj, functionName, args){
        var formattedArgs = [];
        for (var i = 0, l = args.length; i < l; i++)
        {
            if (typeof args[i] == "function")
            {
                formattedArgs.push("f");
                var cbID = "__cb" + (+new Date);
                EasyJS.__callbacks[cbID] = args[i];formattedArgs.push(cbID);
            }else{
                formattedArgs.push("s");
                formattedArgs.push(encodeURIComponent(args[i]));
            }
        }
        var argStr = (formattedArgs.length > 0 ? ":" + encodeURIComponent(formattedArgs.join(":")) : "");
        var iframe = document.createElement("IFRAME");
        iframe.setAttribute("src", "easy-js:" + obj + ":" + encodeURIComponent(functionName) + argStr);
        document.documentElement.appendChild(iframe);
        iframe.parentNode.removeChild(iframe);
        iframe = null;
        var ret = EasyJS.retValue;EasyJS.retValue = undefined;
        if (ret){
            return decodeURIComponent(ret);
        }
    },
//讲OC的方法,注入到JS代码中,实现JS回调OC的方法
inject: 
    function (obj, methods){
        window[obj] = {};
        var jsObj = window[obj];
        for (var i = 0, l = methods.length; i < l; i++)
        {
            (
            function (){
                var method = methods[i];
                var jsMethod = method.replace(new RegExp(":", "g"), "");
                jsObj[jsMethod] = function ()
                    {
                    return EasyJS.call(obj, method, Array.prototype.slice.call(arguments));
                    };
                }
            )();
        }
    }

};

EasyJSWebViewProxyDelegate实现UIWebView的代理方法

下面有一段通过函数名来调用一个对象的函数的涉及到两个类:NSMethodSignature `` NSInvocation


- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
    
    NSString *requestString = [[request URL] absoluteString];
    if ([requestString hasPrefix:@"easy-js:"]) {
        /*
         A sample URL structure:
         easy-js:MyJSTest:test
         easy-js:MyJSTest:testWithParam%3A:haha
         */
        NSArray *components = [requestString componentsSeparatedByString:@":"];
        //NSLog(@"req: %@", requestString);
        
        NSString* obj = (NSString*)[components objectAtIndex:1];
        NSString* method = [(NSString*)[components objectAtIndex:2]
                            stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
        
        NSObject* interface = [javascriptInterfaces objectForKey:obj];
        
        // execute the interfacing method
        SEL selector = NSSelectorFromString(method);
        // 获取方法签名
        NSMethodSignature* sig = [[interface class] instanceMethodSignatureForSelector:selector];
        // 获取invoker对象
        NSInvocation* invoker = [NSInvocation invocationWithMethodSignature:sig];
        invoker.selector = selector;
        invoker.target = interface;
        
        NSMutableArray* args = [[NSMutableArray alloc] init];
        
        // 获取参数
        if ([components count] > 3){
            NSString *argsAsString = [(NSString*)[components objectAtIndex:3]
                                      stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
            
            NSArray* formattedArgs = [argsAsString componentsSeparatedByString:@":"];
            for (int i = 0, j = 0, l = [formattedArgs count]; i < l; i+=2, j++){
                NSString* type = ((NSString*) [formattedArgs objectAtIndex:i]);
                NSString* argStr = ((NSString*) [formattedArgs objectAtIndex:i + 1]);
                
                if ([@"f" isEqualToString:type]){
                    EasyJSDataFunction* func = [[EasyJSDataFunction alloc] initWithWebView:(EasyJSWebView *)webView];
                    func.funcID = argStr;
                    [args addObject:func];
                    [invoker setArgument:&func atIndex:(j + 2)];
                }else if ([@"s" isEqualToString:type]){
                //invoker 传入参数
                    NSString* arg = [argStr stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
                    [args addObject:arg];
                    [invoker setArgument:&arg atIndex:(j + 2)];
                }
            }
        }
        //调用函数
        [invoker invoke];
        
        //return the value by using javascript
        if ([sig methodReturnLength] > 0){
            NSString* retValue;
            [invoker getReturnValue:&retValue];
            
            if (retValue == NULL || retValue == nil){
                [webView stringByEvaluatingJavaScriptFromString:@"EasyJS.retValue=null;"];
            }else{
                retValue = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(NULL,(CFStringRef) retValue, NULL, (CFStringRef)@"!*'();:@&=+$,/?%#[]", kCFStringEncodingUTF8));
                [webView stringByEvaluatingJavaScriptFromString:[@"" stringByAppendingFormat:@"EasyJS.retValue=\"%@\";", retValue]];
            }
        }
        
    
        
        return NO;
    }
    
    if (! self.realDelegate){
        return YES;
    }
    
    return [self.realDelegate webView:webView shouldStartLoadWithRequest:request navigationType:navigationType];
}


一、OC 调用 JS

  NSString *jsCode = 
                    @"var demoP =  document.getElementById('demo');"
                    @"demoP.innerHTML = 'ios write'";
  [_webView stringByEvaluatingJavaScriptFromString:jsCode];

二、JS 调用 OC

2.使用JavascriptCore

OC代码

JSTextObjext

    //JSTestObjext.h
    
    @protocol JSTextObjectProtocol <JSExport>
    
    - (void)callOCFunction;
    - (void)callOCFunctionWithFirstParments:(NSString *)parmentOne;
    - (void)callOCFunctionWithFirstParments:(NSString *)parmentone SecondParments:(NSString *)parmentsTwo;
    
    @end
    
    @interface JSTestObjext : NSObject <JSTextObjectProtocol>
    
    @end
    
    //JSTestObjext.m
    @implementation JSTestObjext

    - (void)callOCFunction
    {
        NSLog(@"callOCFunction");
    }
    - (void)callOCFunctionWithFirstParments:(NSString *)parmentOne
    {
        NSLog(@"callOCFunctionWithFirstParments %@",parmentOne);
    }
    - (void)callOCFunctionWithFirstParments:(NSString *)parmentone SecondParments:(NSString *)parmentsTwo
    {
         NSLog(@"callOCFunctionWithFirstParments one %@  two %@",parmentone, parmentsTwo );
    }
    @end

在webview 加载完后创建想context 注册

    #pragma UIWebViewDelegate
-(void)webViewDidFinishLoad:(UIWebView *)webView
{
    JSContext *context = [webView valueForKeyPath:@"documentView.webView.mainFrame.javaScriptContext"];
    JSTestObjext *obj =  [JSTestObjext new];
    
    // JS调用OC的对象方法
    context[@"testObj"] = obj;
    
    //JS调用OC的Block方法
    context[@"log"] = ^(){
        NSLog(@"log log log");
        NSArray *argument = [JSContext currentArguments];
        if (argument.count < 3) {
            return ;
        }
        
        NSString *onePar = [argument[0] toString];
        NSString *twoPar = [argument[1] toString];
        NSString *thrPar = [argument[2] toString];
        NSLog(@" %@ %@ %@", onePar, twoPar, thrPar);
        
        NSString *shareSuccess = [NSString stringWithFormat:@"showAlert(%@)",onePar];
        [[JSContext currentContext]evaluateScript:shareSuccess];
    };
}

JS调用

// JQuery 的写法,$() 就是JS的document.getElementById()
$(document).ready(function () {
  console.log("xxxxxxxxx");
  $("#get_cookie").click(function () {
  
    // 调用想context注册的方法
    testObj.callOCFunction();
 
    
  });
});

JS与OC交互方案

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