IOS Object and javaScript call each other

In IOS development, objects and javaScript are sometimes used to call each other. The specific steps are as follows:

1. execute javascript code in the Object. This is relatively simple. Apple provides a good method.

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

2. The data returned to the Object during javascript execution or the Object method is called.

The main code of the address redirection function of UIWebView is as follows:

(1) create a UIWebView

    webView = [[UIWebView alloc] initWithFrame:self.view.bounds];    webView.delegate = self;    [self.view addSubview:webView];    [self loadWebPageWithString:_url];- (void)loadWebPageWithString:(NSString*)urlString{    NSURL *url =[NSURL URLWithString:urlString];    NSURLRequest *request =[NSURLRequest requestWithURL:url];    [webView loadRequest:request];}

(2) Implement the UIWebView Method

#pragma mark - UIWebViewDelegate- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{    NSString *urlString = [[request URL] absoluteString];    debuglog(@"urlString = %@",urlString);    NSString *prefix = @"myvideo";    if ([urlString hasPrefix:prefix]) {        NSString *endString = [urlString substringFromIndex:7];        debuglog(@"last urlString = %@",endString);                return NO;    }    return YES;}- (void)webViewDidStartLoad:(UIWebView *)webView{    }- (void)webViewDidFinishLoad:(UIWebView *)webView{    [self excuteJavaScript];}- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error{    }- (void)excuteJavaScript{    NSString *js = @"var video =  document.getElementsByTagName('video')[0];setTimeout(getVideo,1000); function getVideo(){ video =  document.getElementsByTagName('video')[0];if(video==undefined){setTimeout(getVideo,1000);}else{ video.pause();if(video.src==''){var video = document.getElementsByTagName('source')[0];}document.location = 'myvideo'+ video.getAttribute('src');injectedObject.playVideo(video.getAttribute('src'));}}";    [webView stringByEvaluatingJavaScriptFromString:js];}

Description:

(1) When the UIWebView loads the webpage, it executes a javascript code when the webViewDidFinishLoad proxy is executed. The purpose of this Code is to obtain the video address in the webpage, in which "document. location = 'myvideo' + video. getAttribute ('src'); "This section is particularly important, document. location is used for address redirection. After the javascript code is executed

-(BOOL) webView :( UIWebView *) webView shouldStartLoadWithRequest :( NSURLRequest *) request navigationType :( UIWebViewNavigationType) The navigationType proxy method will capture the document. the address given by location is 'myvideo' + video. getAttribute ('src ');. You can remove the 'myvideo' header to get what you need. 'myvideo' is a custom header to facilitate data parsing.