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在WebKit中,如何获取资源的内容?

webview webkit objective-c

fernyb · 技术社区 · 16 年前

我一直在编写一个mac应用程序来检查每个HTTP请求,所以我使用webview来加载请求。

问题是,我似乎不知道如何获取每个资源项的内容。

我正在尝试通过 WebResourceLoadDelegate 方法:

- (void)webView:(WebView *)sender resource:(id)identifier didFinishLoadingFromDataSource:(WebDataSource *)dataSource

这似乎不起作用。

我也在看 [dataSource data] 但这只给了我请求的HTML,而不是资源项的数据。

关于如何获取资源的内容有什么想法吗?

2 回复 | 直到 14 年前

J. Perkins 15 年前

是的,这应该是可行的,而且似乎很久以前就有了。您可以通过实现一个定制的nsurlprotocol来解决这个问题。

首先,您需要弄清楚您对拦截感兴趣的请求(或者所有请求,不管是什么)。我在WebResourceLoadDelegate中执行此操作。如果我关心这个请求,我会用自己的一个来替换它,把自己作为一个财产。稍后我将在nsurlprotocol中使用该属性。

- (NSURLRequest*) webView:(WebView*)sender 
                 resource:(id)identifier 
          willSendRequest:(NSURLRequest*)request 
         redirectResponse:(NSURLResponse*)redirectResponse     
           fromDataSource:(WebDataSource*)dataSource
{
    // Am I interested in this request?
    if (/* figure out if you want it or not */) {
        NSMutableURLRequest* newRequest = [[request mutableCopy] autorelease];
        [NSURLProtocol setProperty:self forKey:@"MyApp" inRequest:newRequest];
        return newRequest;
    }
    else {  
        // Not interested, let it go through normally
        return request;
    }
}

我的nsurlprotocol看起来像这样。

@interface MyURLProtocol : NSURLProtocol {
    id _delegate;
    NSURLConnection* _connection;
    NSMutableData* _data;
}
@end

在我的nsurlprotocol子类中,我可以使用附加属性来查看是否应该拦截响应。

+ (BOOL) canInitWithRequest:(NSURLRequest*)request
{   
    id delegate = [NSURLProtocol propertyForKey:@"MyApp" inRequest:request];
    return (delegate != nil);
}

在initwithrequest中,我将委托移动到我的nsurlprotocol实例中,并从请求中移除属性。当我实际尝试加载这个请求时,这会阻止无限循环。

- (id) initWithRequest:(NSURLRequest*)theRequest 
        cachedResponse:(NSCachedURLResponse*)cachedResponse 
                client:(id<NSURLProtocolClient>)client
{
    // Move the delegate from the request to this instance
    NSMutableURLRequest* req = (NSMutableURLRequest*)theRequest;    
    _delegate = [NSURLProtocol propertyForKey:@"MyApp" inRequest:req];  
    [NSURLProtocol removePropertyForKey:@"MyApp" inRequest:req];

    // Complete my setup
    self = [super initWithRequest:req cachedResponse:cachedResponse client:client];
    if (self) {
        _data = [[NSMutableData data] retain];
    }
    return self;
}

剩下的是股票URL加载的东西。

- (void) startLoading
{
    _connection = [[NSURLConnection connectionWithRequest:[self request] delegate:self] retain];
}

- (void) stopLoading
{
    [_connection cancel];
}

- (void)connection:(NSURLConnection*)conn didReceiveResponse:(NSURLResponse*)response 
{
    [[self client] URLProtocol:self didReceiveResponse:response cacheStoragePolicy:[[self request] cachePolicy]];
    [_data setLength:0];
}

- (void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data
{
    [[self client] URLProtocol:self didLoadData:data];
    [_data appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection*)conn
{
    [[self client] URLProtocolDidFinishLoading:self];

    // Forward the response to your delegate however you like
    if (_delegate && [_delegate respondsToSelector:@selector(...)]) {
        [_delegate ... withRequest:[self request] withData:_data];
    }
}

- (NSURLRequest*)connection:(NSURLConnection*)connection willSendRequest:(NSURLRequest*)theRequest redirectResponse:(NSURLResponse*)redirectResponse
{
    return theRequest;
}

- (void)connection:(NSURLConnection*)conn didFailWithError:(NSError*)error 
{
    [[self client] URLProtocol:self didFailWithError:error];
}

amrit_neo 15 年前

在那个委托方法中使用这个

  for(NSString *s in [dataSource subresources])
        NSLog(@"resource : %@",s);

它将显示WebDataSource中正在下载的所有资源