zoukankan      html  css  js  c++  java
  • [转]UIWebView 监控 XMLHttpRequest

    需要 Javascript 与 ObjC 合作从而达到这个目标。

    There are two parts to make this work: a JavaScript handler and UIWebView delegate methods. In JavaScript, we can modify prototype methods to trigger events when an AJAX request is created. With our UIWebView delegate, we can capture these events.

    JavaScript Handler

    We need to be notified when an AJAX request is made. I found the solution here.

    In our case, to make the code work, I put the following JavaScript in a resource called ajax_handler.js which is bundled with my app.

    var s_ajaxListener = new Object();
    s_ajaxListener.tempOpen = XMLHttpRequest.prototype.open;
    s_ajaxListener.tempSend = XMLHttpRequest.prototype.send;
    s_ajaxListener.callback = function () {
        window.location='mpAjaxHandler://' + this.url;
    };
    
    XMLHttpRequest.prototype.open = function(a,b) {
      if (!a) var a='';
      if (!b) var b='';
      s_ajaxListener.tempOpen.apply(this, arguments);
      s_ajaxListener.method = a;  
      s_ajaxListener.url = b;
      if (a.toLowerCase() == 'get') {
        s_ajaxListener.data = b.split('?');
        s_ajaxListener.data = s_ajaxListener.data[1];
      }
    }
    
    XMLHttpRequest.prototype.send = function(a,b) {
      if (!a) var a='';
      if (!b) var b='';
      s_ajaxListener.tempSend.apply(this, arguments);
      if(s_ajaxListener.method.toLowerCase() == 'post')s_ajaxListener.data = a;
      s_ajaxListener.callback();
    }

    What this will actually do is change the location of the browser to some made up URL scheme (in this case,mpAjaxHandle) with info about the request made. Don't worry, our delegate with catch this and the location won't change.

    UIWebView Delegate

    First, we need to read our JavaScript file. I suggest doing storing it in a static variable. I'm in the habit of using +initialize.

    static NSString *JSHandler;
    
    + (void)initialize {
        JSHandler = [[NSString stringWithContentsOfURL:[[NSBundle mainBundle] URLForResource:@"ajax_handler" withExtension:@"js"] encoding:NSUTF8StringEncoding error:nil] retain];
    }

    Next, we want to inject this JavaScript before a page is done loading so we can receive all events.

    - (void)webViewDidStartLoad:(UIWebView *)webView {
        [webView stringByEvaluatingJavaScriptFromString:JSHandler];
    }

    Finally, we want to capture the event.

    Since the URL Scheme is made up, we don't want to actually follow it. We return NO and all is well.

    #define CocoaJSHandler          @"mpAjaxHandler"
    
    - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
        if ([[[request URL] scheme] isEqual:CocoaJSHandler]) {
            NSString *requestedURLString = [[[request URL] absoluteString] substringFromIndex:[CocoaJSHandler length] + 3];
    
            NSLog(@"ajax request: %@", requestedURLString);
            return NO;
        }
    
        return YES;
    }

    I created a sample project with the solution but have nowhere to host it. You can message me if you can host it and I'll edit this post accordingly.

  • 相关阅读:
    自我介绍+软工5问
    团队展示&选题
    团队展示&选题 (白衣天使队)
    结对编程(-java-实现)
    个人项目wc(Java)
    自我介绍+软工五问
    软件工程结课作业
    第四次博客作业-结对项目
    软件工程第三次作业——关于软件质量保障初探
    20194613 自动生成四则运算第一版报告
  • 原文地址:https://www.cnblogs.com/Proteas/p/2848932.html
Copyright © 2011-2022 走看看